mxf: Add MXF muxer

This muxer currently only supports OP1a and is
probably not yet 100% complying to the standards.

11 files changed, 4431 insertions, 10 deletions

diff --git a/gst/mxf/Makefile.am b/gst/mxf/Makefile.am
index 499ac625..c5eef4b6 100644
--- a/gst/mxf/Makefile.am
+++ b/gst/mxf/Makefile.am
@@ -14,7 +14,9 @@ libgstmxf_la_SOURCES = \
 	mxfup.c \
 	mxfvc3.c \
 	mxfmetadata.c \
-	mxfdms1.c
+	mxfdms1.c \
+	mxfwrite.c \
+	mxfmux.c
 
 libgstmxf_la_CFLAGS = $(GST_CFLAGS) $(GST_BASE_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS)
 libgstmxf_la_LIBADD = $(GST_LIBS) $(GST_BASE_LIBS) $(GST_PLUGINS_BASE_LIBS) \
@@ -35,5 +37,7 @@ noinst_HEADERS = \
 	mxfvc3.h \
 	mxftypes.h \
 	mxfmetadata.h \
-	mxfdms1.h
+	mxfdms1.h \
+	mxfwrite.h \
+	mxfmux.h
 
diff --git a/gst/mxf/mxf.c b/gst/mxf/mxf.c
index ec477721..a906f1d8 100644
--- a/gst/mxf/mxf.c
+++ b/gst/mxf/mxf.c
@@ -24,6 +24,7 @@
 
 #include "mxfquark.h"
 #include "mxfdemux.h"
+#include "mxfmux.h"
 #include "mxfaes-bwf.h"
 #include "mxfmpeg.h"
 #include "mxfdv-dif.h"
@@ -53,6 +54,8 @@ mxf_init (void)
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
+  GST_DEBUG_CATEGORY_INIT (mxf_debug, "mxf", 0, "MXF");
+
   mxf_init ();
   mxf_quark_initialize ();
   mxf_metadata_init_types ();
@@ -67,11 +70,10 @@ plugin_init (GstPlugin * plugin)
   mxf_dms1_initialize ();
 
   if (!gst_element_register (plugin, "mxfdemux", GST_RANK_PRIMARY,
-          GST_TYPE_MXF_DEMUX))
+          GST_TYPE_MXF_DEMUX) ||
+      !gst_element_register (plugin, "mxfmux", GST_RANK_NONE, GST_TYPE_MXF_MUX))
     return FALSE;
 
-  GST_DEBUG_CATEGORY_INIT (mxf_debug, "mxf", 0, "MXF");
-
   return TRUE;
 }
 
diff --git a/gst/mxf/mxfmetadata.c b/gst/mxf/mxfmetadata.c
index cc53ec15..29bd8a5f 100644
--- a/gst/mxf/mxfmetadata.c
+++ b/gst/mxf/mxfmetadata.c
@@ -27,6 +27,7 @@
 #include "mxfparse.h"
 #include "mxfmetadata.h"
 #include "mxfquark.h"
+#include "mxfwrite.h"
 
 GST_DEBUG_CATEGORY_EXTERN (mxf_debug);
 #define GST_CAT_DEFAULT mxf_debug
@@ -238,6 +239,115 @@ mxf_metadata_base_to_structure (MXFMetadataBase * self)
   return NULL;
 }
 
+GstBuffer *
+mxf_metadata_base_to_buffer (MXFMetadataBase * self, MXFPrimerPack * primer)
+{
+  MXFMetadataBaseClass *klass;
+  GstBuffer *ret;
+  GList *tags, *l;
+  guint size = 0, slen;
+  guint8 ber[9];
+  MXFLocalTag *t, *last;
+  guint8 *data;
+
+  g_return_val_if_fail (MXF_IS_METADATA_BASE (self), NULL);
+  g_return_val_if_fail (primer != NULL, NULL);
+
+  klass = MXF_METADATA_BASE_GET_CLASS (self);
+  g_return_val_if_fail (klass->write_tags, NULL);
+
+  tags = klass->write_tags (self, primer);
+  g_return_val_if_fail (tags != NULL, NULL);
+
+  /* Add unknown tags */
+  if (self->other_tags) {
+    MXFLocalTag *tmp;
+#if GLIB_CHECK_VERSION (2, 16, 0)
+    GHashTableIter iter;
+
+    g_hash_table_iter_init (&iter, self->other_tags);
+#else
+    GList *l, *values;
+
+    values = g_hash_table_get_values (self->other_tags);
+#endif
+
+#if GLIB_CHECK_VERSION (2, 16, 0)
+    while (g_hash_table_iter_next (&iter, NULL, (gpointer) & t)) {
+#else
+    for (l = values; l; l = l->next) {
+      t = l->data;
+#endif
+      tmp = g_slice_dup (MXFLocalTag, t);
+      if (t->g_slice) {
+        tmp->data = g_slice_alloc (t->size);
+        mxf_primer_pack_add_mapping (primer, 0x0000, &t->key);
+        memcpy (tmp->data, t->data, t->size);
+      } else {
+        tmp->data = g_memdup (t->data, t->size);
+      }
+      tags = g_list_prepend (tags, tmp);
+    }
+
+#if !GLIB_CHECK_VERSION (2, 16, 0)
+    g_list_free (values);
+#endif
+  }
+
+  l = g_list_last (tags);
+  last = l->data;
+  tags = g_list_delete_link (tags, l);
+  /* Last element contains the metadata UL */
+  g_return_val_if_fail (last->size == 0, NULL);
+
+  for (l = tags; l; l = l->next) {
+    t = l->data;
+    g_assert (G_MAXUINT - t->size >= size);
+    size += 4 + t->size;
+  }
+
+  slen = mxf_ber_encode_size (size, ber);
+  size += 16 + slen;
+
+  ret = gst_buffer_new_and_alloc (size);
+
+  memcpy (GST_BUFFER_DATA (ret), &last->key, 16);
+  mxf_local_tag_free (last);
+  last = NULL;
+  memcpy (GST_BUFFER_DATA (ret) + 16, ber, slen);
+
+  data = GST_BUFFER_DATA (ret) + 16 + slen;
+  size -= 16 + slen;
+
+  for (l = tags; l; l = l->next) {
+    guint16 local_tag;
+
+    g_assert (size >= 4);
+    t = l->data;
+
+    local_tag =
+        GPOINTER_TO_UINT (g_hash_table_lookup (primer->reverse_mappings,
+            &t->key));
+    g_assert (local_tag != 0);
+
+    GST_WRITE_UINT16_BE (data, local_tag);
+    GST_WRITE_UINT16_BE (data + 2, t->size);
+    data += 4;
+    size -= 4;
+    g_assert (size >= t->size);
+
+    memcpy (data, t->data, t->size);
+    data += t->size;
+    size -= t->size;
+
+    mxf_local_tag_free (t);
+  }
+
+  g_list_free (tags);
+
+  return ret;
+}
+
 G_DEFINE_ABSTRACT_TYPE (MXFMetadata, mxf_metadata, MXF_TYPE_METADATA_BASE);
 
 static gboolean
@@ -281,12 +391,65 @@ error:
   return FALSE;
 }
 
+static GList *
+mxf_metadata_write_tags (MXFMetadataBase * m, MXFPrimerPack * primer)
+{
+  MXFMetadata *self = MXF_METADATA (m);
+  GList *ret = NULL;
+  MXFLocalTag *t;
+  MXFMetadataClass *klass;
+  static const guint8 metadata_key[] = {
+    0x06, 0x0e, 0x2b, 0x34, 0x02, 0x53, 0x01, 0x01,
+    0x0d, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 instance_uid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x01, 0x01, 0x15, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 generation_uid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x01, 0x00, 0x00, 0x00
+  };
+
+  g_return_val_if_fail (MXF_IS_METADATA (self), NULL);
+  klass = MXF_METADATA_GET_CLASS (self);
+
+  /* Last element contains the metadata key */
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, metadata_key, 16);
+  GST_WRITE_UINT16_BE (&t->key.u[13], klass->type);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &instance_uid_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (16);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->parent.instance_uid, 16);
+  mxf_primer_pack_add_mapping (primer, 0x3c0a, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (!mxf_ul_is_zero (&self->parent.generation_uid)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &generation_uid_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (16);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->parent.generation_uid, 16);
+    mxf_primer_pack_add_mapping (primer, 0x0102, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_class_init (MXFMetadataClass * klass)
 {
   MXFMetadataBaseClass *metadata_base_class = (MXFMetadataBaseClass *) klass;
 
   metadata_base_class->handle_tag = mxf_metadata_handle_tag;
+  metadata_base_class->write_tags = mxf_metadata_write_tags;
 }
 
 static void
@@ -712,6 +875,159 @@ mxf_metadata_preface_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_preface_write_tags (MXFMetadataBase * m, MXFPrimerPack * primer)
+{
+  MXFMetadataPreface *self = MXF_METADATA_PREFACE (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS (mxf_metadata_preface_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  guint i;
+  static const guint8 last_modified_date_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x10, 0x02, 0x04, 0x00, 0x00
+  };
+  static const guint8 version_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x03, 0x01, 0x02, 0x01, 0x05, 0x00, 0x00, 0x00
+  };
+  static const guint8 object_model_version_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x03, 0x01, 0x02, 0x01, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 primary_package_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x06, 0x01, 0x01, 0x04, 0x01, 0x08, 0x00, 0x00
+  };
+  static const guint8 identifications_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x06, 0x04, 0x00, 0x00
+  };
+  static const guint8 content_storage_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x02, 0x01, 0x00, 0x00
+  };
+  static const guint8 operational_pattern_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x01, 0x02, 0x02, 0x03, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 essence_containers_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x01, 0x02, 0x02, 0x10, 0x02, 0x01, 0x00, 0x00
+  };
+  static const guint8 dm_schemes_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x01, 0x02, 0x02, 0x10, 0x02, 0x02, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &last_modified_date_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (8);
+  t->g_slice = TRUE;
+  mxf_timestamp_write (&self->last_modified_date, t->data);
+  mxf_primer_pack_add_mapping (primer, 0x3b02, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &version_ul, 16);
+  t->size = 2;
+  t->data = g_slice_alloc (2);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT16_BE (t->data, self->version);
+  mxf_primer_pack_add_mapping (primer, 0x3b05, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->object_model_version) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &object_model_version_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (4);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->object_model_version);
+    mxf_primer_pack_add_mapping (primer, 0x3b07, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_ul_is_zero (&self->primary_package_uid)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &primary_package_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (16);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->primary_package_uid, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3b08, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &identifications_ul, 16);
+  t->size = 8 + 16 * self->n_identifications;
+  t->data = g_slice_alloc0 (t->size);
+  t->g_slice = TRUE;
+  mxf_primer_pack_add_mapping (primer, 0x3b06, &t->key);
+  GST_WRITE_UINT32_BE (t->data, self->n_identifications);
+  GST_WRITE_UINT32_BE (t->data + 4, 16);
+  for (i = 0; i < self->n_identifications; i++) {
+    if (!self->identifications[i])
+      continue;
+
+    memcpy (t->data + 8 + 16 * i,
+        &MXF_METADATA_BASE (self->identifications[i])->instance_uid, 16);
+  }
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &content_storage_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  mxf_primer_pack_add_mapping (primer, 0x3b03, &t->key);
+  memcpy (t->data, &MXF_METADATA_BASE (self->content_storage)->instance_uid,
+      16);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &operational_pattern_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  mxf_primer_pack_add_mapping (primer, 0x3b09, &t->key);
+  memcpy (t->data, &self->operational_pattern, 16);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &essence_containers_ul, 16);
+  t->size = 8 + 16 * self->n_essence_containers;
+  t->data = g_slice_alloc0 (t->size);
+  t->g_slice = TRUE;
+  mxf_primer_pack_add_mapping (primer, 0x3b0a, &t->key);
+  GST_WRITE_UINT32_BE (t->data, self->n_essence_containers);
+  GST_WRITE_UINT32_BE (t->data + 4, 16);
+  for (i = 0; i < self->n_essence_containers; i++) {
+    memcpy (t->data + 8 + 16 * i, &self->essence_containers[i], 16);
+  }
+  ret = g_list_prepend (ret, t);
+
+  if (self->dm_schemes) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &dm_schemes_ul, 16);
+    t->size = 8 + 16 * self->n_dm_schemes;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    mxf_primer_pack_add_mapping (primer, 0x3b0b, &t->key);
+    GST_WRITE_UINT32_BE (t->data, self->n_dm_schemes);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_dm_schemes; i++) {
+      memcpy (t->data + 8 + 16 * i, &self->dm_schemes[i], 16);
+    }
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_preface_init (MXFMetadataPreface * self)
 {
@@ -729,6 +1045,7 @@ mxf_metadata_preface_class_init (MXFMetadataPrefaceClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_preface_handle_tag;
   metadata_base_class->resolve = mxf_metadata_preface_resolve;
   metadata_base_class->to_structure = mxf_metadata_preface_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_preface_write_tags;
   metadata_base_class->name_quark = MXF_QUARK (PREFACE);
   metadata_class->type = 0x012f;
 }
@@ -912,6 +1229,127 @@ mxf_metadata_identification_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_identification_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataIdentification *self = MXF_METADATA_IDENTIFICATION (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_identification_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 company_name_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x02, 0x01, 0x00, 0x00
+  };
+  static const guint8 product_name_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x03, 0x01, 0x00, 0x00
+  };
+  static const guint8 product_version_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 version_string_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x05, 0x01, 0x00, 0x00
+  };
+  static const guint8 product_uid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x07, 0x00, 0x00, 0x00
+  };
+  static const guint8 modification_date_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x10, 0x02, 0x03, 0x00, 0x00
+  };
+  static const guint8 toolkit_version_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x0A, 0x00, 0x00, 0x00
+  };
+  static const guint8 platform_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x07, 0x01, 0x06, 0x01, 0x00, 0x00
+  };
+
+  if (self->company_name) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &company_name_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->company_name, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x3c01, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->product_name) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &product_name_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->product_name, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x3c02, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_product_version_is_valid (&self->product_version)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &product_version_ul, 16);
+    t->size = 10;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    mxf_product_version_write (&self->product_version, t->data);
+    mxf_primer_pack_add_mapping (primer, 0x3c03, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->version_string) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &version_string_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->version_string, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x3c04, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_ul_is_zero (&self->product_uid)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &product_uid_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->product_uid, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3c05, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_timestamp_is_unknown (&self->modification_date)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &modification_date_ul, 16);
+    t->size = 8;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    mxf_timestamp_write (&self->modification_date, t->data);
+    mxf_primer_pack_add_mapping (primer, 0x3c06, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_product_version_is_valid (&self->toolkit_version)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &toolkit_version_ul, 16);
+    t->size = 10;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    mxf_product_version_write (&self->toolkit_version, t->data);
+    mxf_primer_pack_add_mapping (primer, 0x3c07, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->platform) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &platform_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->platform, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x3c08, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_identification_init (MXFMetadataIdentification * self)
 {
@@ -929,6 +1367,7 @@ mxf_metadata_identification_class_init (MXFMetadataIdentificationClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_identification_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (IDENTIFICATION);
   metadata_base_class->to_structure = mxf_metadata_identification_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_identification_write_tags;
   metadata_class->type = 0x0130;
 }
 
@@ -1151,6 +1590,69 @@ mxf_metadata_content_storage_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_content_storage_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataContentStorage *self = MXF_METADATA_CONTENT_STORAGE (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_content_storage_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  guint i;
+  static const guint8 packages_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x05, 0x01, 0x00, 0x00
+  };
+  static const guint8 essence_container_data_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x05, 0x02, 0x00, 0x00
+  };
+
+  if (self->packages) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &packages_ul, 16);
+    t->size = 8 + 16 * self->n_packages;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_packages);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_packages; i++) {
+      if (!self->packages[i])
+        continue;
+
+      memcpy (t->data + 8 + i * 16,
+          &MXF_METADATA_BASE (self->packages[i])->instance_uid, 16);
+    }
+
+    mxf_primer_pack_add_mapping (primer, 0x1901, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->essence_container_data) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &essence_container_data_ul, 16);
+    t->size = 8 + 16 * self->n_essence_container_data;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_essence_container_data);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_essence_container_data; i++) {
+      if (!self->essence_container_data[i])
+        continue;
+
+      memcpy (t->data + 8 + i * 16,
+          &MXF_METADATA_BASE (self->essence_container_data[i])->instance_uid,
+          16);
+    }
+
+    mxf_primer_pack_add_mapping (primer, 0x1902, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_content_storage_init (MXFMetadataContentStorage * self)
 {
@@ -1169,6 +1671,7 @@ mxf_metadata_content_storage_class_init (MXFMetadataContentStorageClass * klass)
   metadata_base_class->resolve = mxf_metadata_content_storage_resolve;
   metadata_base_class->name_quark = MXF_QUARK (CONTENT_STORAGE);
   metadata_base_class->to_structure = mxf_metadata_content_storage_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_content_storage_write_tags;
   metadata_class->type = 0x0118;
 }
 
@@ -1298,6 +1801,63 @@ mxf_metadata_essence_container_data_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_essence_container_data_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataEssenceContainerData *self =
+      MXF_METADATA_ESSENCE_CONTAINER_DATA (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_essence_container_data_parent_class)->write_tags (m,
+      primer);
+  MXFLocalTag *t;
+  static const guint8 linked_package_uid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x06, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 body_sid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x01, 0x03, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 index_sid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x01, 0x03, 0x04, 0x05, 0x00, 0x00, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &linked_package_uid_ul, 16);
+  t->size = 32;
+  t->data = g_slice_alloc0 (32);
+  t->g_slice = TRUE;
+  if (self->linked_package)
+    memcpy (t->data, &self->linked_package->parent.package_uid, 32);
+  mxf_primer_pack_add_mapping (primer, 0x2701, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &body_sid_ul, 16);
+  t->size = 4;
+  t->data = g_slice_alloc (4);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->body_sid);
+  mxf_primer_pack_add_mapping (primer, 0x3f07, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->index_sid) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &index_sid_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (4);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->index_sid);
+    mxf_primer_pack_add_mapping (primer, 0x3f07, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_essence_container_data_init (MXFMetadataEssenceContainerData *
     self)
@@ -1318,6 +1878,8 @@ static void
   metadata_base_class->name_quark = MXF_QUARK (ESSENCE_CONTAINER_DATA);
   metadata_base_class->to_structure =
       mxf_metadata_essence_container_data_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_essence_container_data_write_tags;
   metadata_class->type = 0x0123;
 }
 
@@ -1518,6 +2080,95 @@ mxf_metadata_generic_package_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_generic_package_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataGenericPackage *self = MXF_METADATA_GENERIC_PACKAGE (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_generic_package_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 package_uid_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x01, 0x01, 0x15, 0x10, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 name_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x01, 0x03, 0x03, 0x02, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 package_creation_date_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x10, 0x01, 0x03, 0x00, 0x00
+  };
+  static const guint8 package_modified_date_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x10, 0x02, 0x05, 0x00, 0x00
+  };
+  static const guint8 tracks_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x06, 0x05, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &package_uid_ul, 16);
+  t->size = 32;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->package_uid, 32);
+  mxf_primer_pack_add_mapping (primer, 0x4401, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->name) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &name_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->name, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x4402, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &package_creation_date_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  mxf_timestamp_write (&self->package_creation_date, t->data);
+  mxf_primer_pack_add_mapping (primer, 0x4405, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &package_modified_date_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  mxf_timestamp_write (&self->package_modified_date, t->data);
+  mxf_primer_pack_add_mapping (primer, 0x4404, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->tracks) {
+    guint i;
+
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &tracks_ul, 16);
+    t->size = 8 + 16 * self->n_tracks;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_tracks);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_tracks; i++) {
+      if (!self->tracks[i])
+        continue;
+
+      memcpy (t->data + 8 + 16 * i,
+          &MXF_METADATA_BASE (self->tracks[i])->instance_uid, 16);
+    }
+    mxf_primer_pack_add_mapping (primer, 0x4403, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_generic_package_init (MXFMetadataGenericPackage * self)
 {
@@ -1534,6 +2185,7 @@ mxf_metadata_generic_package_class_init (MXFMetadataGenericPackageClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_generic_package_handle_tag;
   metadata_base_class->resolve = mxf_metadata_generic_package_resolve;
   metadata_base_class->to_structure = mxf_metadata_generic_package_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_generic_package_write_tags;
 }
 
 G_DEFINE_TYPE (MXFMetadataMaterialPackage, mxf_metadata_material_package,
@@ -1802,6 +2454,34 @@ mxf_metadata_source_package_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_source_package_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataSourcePackage *self = MXF_METADATA_SOURCE_PACKAGE (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_source_package_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 descriptor_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x02, 0x03, 0x00, 0x00
+  };
+
+  if (self->descriptor) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &descriptor_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &MXF_METADATA_BASE (self->descriptor)->instance_uid, 16);
+    mxf_primer_pack_add_mapping (primer, 0x4701, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_source_package_init (MXFMetadataSourcePackage * self)
 {
@@ -1818,6 +2498,7 @@ mxf_metadata_source_package_class_init (MXFMetadataSourcePackageClass * klass)
   metadata_base_class->resolve = mxf_metadata_source_package_resolve;
   metadata_base_class->name_quark = MXF_QUARK (SOURCE_PACKAGE);
   metadata_base_class->to_structure = mxf_metadata_source_package_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_source_package_write_tags;
   metadata_class->type = 0x0137;
 }
 
@@ -1959,6 +2640,69 @@ mxf_metadata_track_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_track_write_tags (MXFMetadataBase * m, MXFPrimerPack * primer)
+{
+  MXFMetadataTrack *self = MXF_METADATA_TRACK (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS (mxf_metadata_track_parent_class)->write_tags (m,
+      primer);
+  MXFLocalTag *t;
+  static const guint8 track_id_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x01, 0x07, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 track_number_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x01, 0x04, 0x01, 0x03, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 track_name_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x01, 0x07, 0x01, 0x02, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 sequence_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x02, 0x04, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &track_id_ul, 16);
+  t->size = 4;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->track_id);
+  mxf_primer_pack_add_mapping (primer, 0x4801, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &track_number_ul, 16);
+  t->size = 4;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->track_number);
+  mxf_primer_pack_add_mapping (primer, 0x4804, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->track_name) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &track_name_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->track_name, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x4802, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &sequence_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &MXF_METADATA_BASE (self->sequence)->instance_uid, 16);
+  mxf_primer_pack_add_mapping (primer, 0x4803, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
+
 static void
 mxf_metadata_track_init (MXFMetadataTrack * self)
 {
@@ -1975,6 +2719,7 @@ mxf_metadata_track_class_init (MXFMetadataTrackClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_track_handle_tag;
   metadata_base_class->resolve = mxf_metadata_track_resolve;
   metadata_base_class->to_structure = mxf_metadata_track_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_track_write_tags;
 }
 
 /* SMPTE RP224 */
@@ -2022,6 +2767,18 @@ mxf_metadata_track_identifier_parse (const MXFUL * track_identifier)
   return MXF_METADATA_TRACK_UNKNOWN;
 }
 
+const MXFUL *
+mxf_metadata_track_identifier_get (MXFMetadataTrackType type)
+{
+  guint i;
+
+  for (i = 0; i < G_N_ELEMENTS (mxf_metadata_track_identifier); i++)
+    if (mxf_metadata_track_identifier[i].type == type)
+      return (const MXFUL *) &mxf_metadata_track_identifier[i].ul;
+
+  return NULL;
+}
+
 G_DEFINE_TYPE (MXFMetadataTimelineTrack, mxf_metadata_timeline_track,
     MXF_TYPE_METADATA_TRACK);
 
@@ -2078,6 +2835,46 @@ mxf_metadata_timeline_track_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_timeline_track_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataTimelineTrack *self = MXF_METADATA_TIMELINE_TRACK (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_timeline_track_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 edit_rate_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x30, 0x04, 0x05, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 origin_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x03, 0x01, 0x03, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &edit_rate_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->edit_rate.n);
+  GST_WRITE_UINT32_BE (t->data + 4, self->edit_rate.d);
+  mxf_primer_pack_add_mapping (primer, 0x4b01, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &origin_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->origin);
+  mxf_primer_pack_add_mapping (primer, 0x4b02, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
+
 static void
 mxf_metadata_timeline_track_init (MXFMetadataTimelineTrack * self)
 {
@@ -2093,6 +2890,7 @@ mxf_metadata_timeline_track_class_init (MXFMetadataTimelineTrackClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_timeline_track_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (TIMELINE_TRACK);
   metadata_base_class->to_structure = mxf_metadata_timeline_track_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_timeline_track_write_tags;
   metadata_class->type = 0x013b;
 }
 
@@ -2152,6 +2950,46 @@ mxf_metadata_event_track_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_event_track_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataEventTrack *self = MXF_METADATA_EVENT_TRACK (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_event_track_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 event_edit_rate_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x30, 0x04, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 event_origin_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x07, 0x02, 0x01, 0x03, 0x01, 0x0B, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &event_edit_rate_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->event_edit_rate.n);
+  GST_WRITE_UINT32_BE (t->data + 4, self->event_edit_rate.d);
+  mxf_primer_pack_add_mapping (primer, 0x4901, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &event_origin_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->event_origin);
+  mxf_primer_pack_add_mapping (primer, 0x4902, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
+
 static void
 mxf_metadata_event_track_init (MXFMetadataEventTrack * self)
 {
@@ -2167,6 +3005,7 @@ mxf_metadata_event_track_class_init (MXFMetadataEventTrackClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_event_track_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (EVENT_TRACK);
   metadata_base_class->to_structure = mxf_metadata_event_track_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_event_track_write_tags;
   metadata_class->type = 0x0139;
 }
 
@@ -2345,6 +3184,71 @@ mxf_metadata_sequence_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_sequence_write_tags (MXFMetadataBase * m, MXFPrimerPack * primer)
+{
+  MXFMetadataSequence *self = MXF_METADATA_SEQUENCE (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS (mxf_metadata_sequence_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 data_definition_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x07, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 duration_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x02, 0x01, 0x01, 0x03, 0x00, 0x00
+  };
+  static const guint8 structural_components_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x06, 0x09, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &data_definition_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->data_definition, 16);
+  mxf_primer_pack_add_mapping (primer, 0x0201, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &duration_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->duration);
+  mxf_primer_pack_add_mapping (primer, 0x0202, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->structural_components) {
+    guint i;
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &structural_components_ul, 16);
+    t->size = 8 + 16 * self->n_structural_components;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+
+    GST_WRITE_UINT32_BE (t->data, self->n_structural_components);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_structural_components; i++) {
+      if (!self->structural_components[i])
+        continue;
+
+      memcpy (t->data + 8 + i * 16,
+          &MXF_METADATA_BASE (self->structural_components[i])->instance_uid,
+          16);
+    }
+
+    mxf_primer_pack_add_mapping (primer, 0x1001, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_sequence_init (MXFMetadataSequence * self)
 {
@@ -2363,6 +3267,7 @@ mxf_metadata_sequence_class_init (MXFMetadataSequenceClass * klass)
   metadata_base_class->resolve = mxf_metadata_sequence_resolve;
   metadata_base_class->name_quark = MXF_QUARK (SEQUENCE);
   metadata_base_class->to_structure = mxf_metadata_sequence_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_sequence_write_tags;
   metadata_class->type = 0x010f;
 }
 
@@ -2429,6 +3334,45 @@ mxf_metadata_structural_component_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_structural_component_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataStructuralComponent *self = MXF_METADATA_STRUCTURAL_COMPONENT (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_structural_component_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 data_definition_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x07, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 duration_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x02, 0x01, 0x01, 0x03, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &data_definition_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->data_definition, 16);
+  mxf_primer_pack_add_mapping (primer, 0x0201, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &duration_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->duration);
+  mxf_primer_pack_add_mapping (primer, 0x0202, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
+
 static void
 mxf_metadata_structural_component_init (MXFMetadataStructuralComponent * self)
 {
@@ -2445,6 +3389,8 @@ static void
       mxf_metadata_structural_component_handle_tag;
   metadata_base_class->to_structure =
       mxf_metadata_structural_component_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_structural_component_write_tags;
 }
 
 G_DEFINE_TYPE (MXFMetadataTimecodeComponent, mxf_metadata_timecode_component,
@@ -2512,6 +3458,58 @@ mxf_metadata_timecode_component_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_timecode_component_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataTimecodeComponent *self = MXF_METADATA_TIMECODE_COMPONENT (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_timecode_component_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 rounded_timecode_base_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x04, 0x01, 0x01, 0x02, 0x06, 0x00, 0x00
+  };
+  static const guint8 start_timecode_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x03, 0x01, 0x05, 0x00, 0x00
+  };
+  static const guint8 drop_frame_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x04, 0x01, 0x01, 0x05, 0x00, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &rounded_timecode_base_ul, 16);
+  t->size = 2;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT16_BE (t->data, self->rounded_timecode_base);
+  mxf_primer_pack_add_mapping (primer, 0x1502, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &start_timecode_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->start_timecode);
+  mxf_primer_pack_add_mapping (primer, 0x1501, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &drop_frame_ul, 16);
+  t->size = 1;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT8 (t->data, (self->drop_frame) ? 1 : 0);
+  mxf_primer_pack_add_mapping (primer, 0x1503, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
+
 static void
 mxf_metadata_timecode_component_init (MXFMetadataTimecodeComponent * self)
 {
@@ -2529,6 +3527,7 @@ mxf_metadata_timecode_component_class_init (MXFMetadataTimecodeComponentClass *
   metadata_base_class->name_quark = MXF_QUARK (TIMECODE_COMPONENT);
   metadata_base_class->to_structure =
       mxf_metadata_timecode_component_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_timecode_component_write_tags;
   metadata_class->type = 0x0114;
 }
 
@@ -2643,6 +3642,57 @@ mxf_metadata_source_clip_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_source_clip_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataSourceClip *self = MXF_METADATA_SOURCE_CLIP (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_source_clip_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 start_position_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x03, 0x01, 0x04, 0x00, 0x00
+  };
+  static const guint8 source_package_id_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x03, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 source_track_id_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x03, 0x02, 0x00, 0x00, 0x00
+  };
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &start_position_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT64_BE (t->data, self->start_position);
+  mxf_primer_pack_add_mapping (primer, 0x1201, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &source_package_id_ul, 16);
+  t->size = 32;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->source_package_id, 32);
+  mxf_primer_pack_add_mapping (primer, 0x1101, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &source_track_id_ul, 16);
+  t->size = 4;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->source_track_id);
+  mxf_primer_pack_add_mapping (primer, 0x1102, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  return ret;
+}
 
 static void
 mxf_metadata_source_clip_init (MXFMetadataSourceClip * self)
@@ -2660,6 +3710,7 @@ mxf_metadata_source_clip_class_init (MXFMetadataSourceClipClass * klass)
   metadata_base_class->resolve = mxf_metadata_source_clip_resolve;
   metadata_base_class->name_quark = MXF_QUARK (SOURCE_CLIP);
   metadata_base_class->to_structure = mxf_metadata_source_clip_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_source_clip_write_tags;
   metadata_class->type = 0x0111;
 }
 
@@ -2771,6 +3822,39 @@ mxf_metadata_dm_source_clip_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_dm_source_clip_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataDMSourceClip *self = MXF_METADATA_DM_SOURCE_CLIP (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_dm_source_clip_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 track_ids_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x01, 0x07, 0x01, 0x06, 0x00, 0x00, 0x00, 0x00
+  };
+
+  if (self->track_ids) {
+    guint i;
+
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &track_ids_ul, 16);
+    t->size = 8 + 4 * self->n_track_ids;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_track_ids);
+    GST_WRITE_UINT32_BE (t->data + 4, 4);
+    for (i = 0; i < self->n_track_ids; i++)
+      GST_WRITE_UINT32_BE (t->data + 8 + i * 4, self->track_ids[i]);
+    mxf_primer_pack_add_mapping (primer, 0x6103, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_dm_source_clip_init (MXFMetadataDMSourceClip * self)
 {
@@ -2788,6 +3872,7 @@ mxf_metadata_dm_source_clip_class_init (MXFMetadataDMSourceClipClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_dm_source_clip_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (DM_SOURCE_CLIP);
   metadata_base_class->to_structure = mxf_metadata_dm_source_clip_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_dm_source_clip_write_tags;
   metadata_class->type = 0x0145;
 }
 
@@ -2965,10 +4050,84 @@ mxf_metadata_dm_segment_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_dm_segment_write_tags (MXFMetadataBase * m, MXFPrimerPack * primer)
+{
+  MXFMetadataDMSegment *self = MXF_METADATA_DM_SEGMENT (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS (mxf_metadata_dm_segment_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 event_start_position_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x07, 0x02, 0x01, 0x03, 0x03, 0x03, 0x00, 0x00
+  };
+  static const guint8 event_comment_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x30, 0x04, 0x04, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 track_ids_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x01, 0x07, 0x01, 0x05, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 dm_framework_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x06, 0x01, 0x01, 0x04, 0x02, 0x0C, 0x00, 0x00
+  };
+
+  if (self->event_start_position != -1) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &event_start_position_ul, 16);
+    t->size = 8;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT64_BE (t->data, self->event_start_position);
+    mxf_primer_pack_add_mapping (primer, 0x0601, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->event_comment) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &event_comment_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->event_comment, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x0602, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->track_ids) {
+    guint i;
+
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &track_ids_ul, 16);
+    t->size = 8 + 4 * self->n_track_ids;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_track_ids);
+    GST_WRITE_UINT32_BE (t->data + 4, 4);
+    for (i = 0; i < self->n_track_ids; i++)
+      GST_WRITE_UINT32_BE (t->data + 8 + i * 4, self->track_ids[i]);
+    mxf_primer_pack_add_mapping (primer, 0x6102, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->dm_framework) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &dm_framework_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &MXF_METADATA_BASE (self->dm_framework)->instance_uid, 16);
+    mxf_primer_pack_add_mapping (primer, 0x6101, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_dm_segment_init (MXFMetadataDMSegment * self)
 {
-
+  self->event_start_position = -1;
 }
 
 static void
@@ -2983,6 +4142,7 @@ mxf_metadata_dm_segment_class_init (MXFMetadataDMSegmentClass * klass)
   metadata_base_class->resolve = mxf_metadata_dm_segment_resolve;
   metadata_base_class->name_quark = MXF_QUARK (DM_SEGMENT);
   metadata_base_class->to_structure = mxf_metadata_dm_segment_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_dm_segment_write_tags;
   metadata_class->type = 0x0141;
 }
 
@@ -3129,6 +4289,43 @@ mxf_metadata_generic_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_generic_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataGenericDescriptor *self = MXF_METADATA_GENERIC_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_generic_descriptor_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 locators_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x06, 0x03, 0x00, 0x00
+  };
+
+  if (self->locators) {
+    guint i;
+
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &locators_ul, 16);
+    t->size = 8 + 16 * self->n_locators;;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_locators);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_locators; i++) {
+      if (!self->locators[i])
+        continue;
+      memcpy (t->data + 8 + 16 * i,
+          &MXF_METADATA_BASE (self->locators[i])->instance_uid, 16);
+    }
+    mxf_primer_pack_add_mapping (primer, 0x2f01, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_generic_descriptor_init (MXFMetadataGenericDescriptor * self)
 {
@@ -3147,6 +4344,7 @@ mxf_metadata_generic_descriptor_class_init (MXFMetadataGenericDescriptorClass *
   metadata_base_class->resolve = mxf_metadata_generic_descriptor_resolve;
   metadata_base_class->to_structure =
       mxf_metadata_generic_descriptor_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_generic_descriptor_write_tags;
 }
 
 G_DEFINE_TYPE (MXFMetadataFileDescriptor, mxf_metadata_file_descriptor,
@@ -3247,6 +4445,91 @@ mxf_metadata_file_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_file_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataFileDescriptor *self = MXF_METADATA_FILE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_file_descriptor_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 linked_track_id_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x06, 0x01, 0x01, 0x03, 0x05, 0x00, 0x00, 0x00
+  };
+  static const guint8 sample_rate_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x06, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 container_duration_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x06, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 essence_container_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x01, 0x02, 0x00, 0x00
+  };
+  static const guint8 codec_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x06, 0x01, 0x01, 0x04, 0x01, 0x03, 0x00, 0x00
+  };
+
+  if (self->linked_track_id) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &linked_track_id_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->linked_track_id);
+    mxf_primer_pack_add_mapping (primer, 0x3006, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &sample_rate_ul, 16);
+  t->size = 8;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT32_BE (t->data, self->sample_rate.n);
+  GST_WRITE_UINT32_BE (t->data + 4, self->sample_rate.d);
+  mxf_primer_pack_add_mapping (primer, 0x3001, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->container_duration > 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &container_duration_ul, 16);
+    t->size = 8;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT64_BE (t->data, self->container_duration);
+    mxf_primer_pack_add_mapping (primer, 0x3002, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &essence_container_ul, 16);
+  t->size = 16;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  memcpy (t->data, &self->essence_container, 16);
+  mxf_primer_pack_add_mapping (primer, 0x3004, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (!mxf_ul_is_zero (&self->codec)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &codec_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->codec, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3005, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_file_descriptor_init (MXFMetadataFileDescriptor * self)
 {
@@ -3262,6 +4545,7 @@ mxf_metadata_file_descriptor_class_init (MXFMetadataFileDescriptorClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_file_descriptor_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (FILE_DESCRIPTOR);
   metadata_base_class->to_structure = mxf_metadata_file_descriptor_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_file_descriptor_write_tags;
   metadata_class->type = 0x0125;
 }
 
@@ -3567,6 +4851,383 @@ mxf_metadata_generic_picture_essence_descriptor_to_structure (MXFMetadataBase *
   return ret;
 }
 
+static GList *
+mxf_metadata_generic_picture_essence_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataGenericPictureEssenceDescriptor *self =
+      MXF_METADATA_GENERIC_PICTURE_ESSENCE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_generic_picture_essence_descriptor_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 signal_standard_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x05, 0x01, 0x13, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 frame_layout_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x03, 0x01, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 stored_width_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x02, 0x02, 0x00, 0x00, 0x00
+  };
+  static const guint8 stored_height_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x02, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 stored_f2_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x03, 0x02, 0x08, 0x00, 0x00, 0x00
+  };
+  static const guint8 sampled_width_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x08, 0x00, 0x00, 0x00
+  };
+  static const guint8 sampled_height_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x07, 0x00, 0x00, 0x00
+  };
+  static const guint8 sampled_x_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x09, 0x00, 0x00, 0x00
+  };
+  static const guint8 sampled_y_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x0A, 0x00, 0x00, 0x00
+  };
+  static const guint8 display_height_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x0B, 0x00, 0x00, 0x00
+  };
+  static const guint8 display_width_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x0C, 0x00, 0x00, 0x00
+  };
+  static const guint8 display_x_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x0D, 0x00, 0x00, 0x00
+  };
+  static const guint8 display_y_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x0E, 0x00, 0x00, 0x00
+  };
+  static const guint8 display_f2_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x03, 0x02, 0x07, 0x00, 0x00, 0x00
+  };
+  static const guint8 aspect_ratio_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 active_format_descriptor_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x03, 0x02, 0x09, 0x00, 0x00, 0x00
+  };
+  static const guint8 video_line_map_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x03, 0x02, 0x05, 0x00, 0x00, 0x00
+  };
+  static const guint8 alpha_transparency_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x05, 0x20, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 capture_gamma_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x02, 0x01, 0x01, 0x01, 0x02, 0x00
+  };
+  static const guint8 image_alignment_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x18, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 image_start_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x18, 0x02, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 image_end_offset_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x18, 0x03, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 field_dominance_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x03, 0x01, 0x06, 0x00, 0x00, 0x00
+  };
+  static const guint8 picture_essence_coding_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+
+  if (self->signal_standard != 1) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &signal_standard_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->signal_standard);
+    mxf_primer_pack_add_mapping (primer, 0x3215, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->frame_layout != 255) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &frame_layout_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->frame_layout);
+    mxf_primer_pack_add_mapping (primer, 0x320c, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->stored_width != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &stored_width_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->stored_width);
+    mxf_primer_pack_add_mapping (primer, 0x3203, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->stored_height != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &stored_height_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->stored_height);
+    mxf_primer_pack_add_mapping (primer, 0x3202, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->stored_f2_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &stored_f2_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->stored_f2_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3216, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->sampled_width != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sampled_width_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->sampled_width);
+    mxf_primer_pack_add_mapping (primer, 0x3205, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->sampled_height != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sampled_height_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->sampled_height);
+    mxf_primer_pack_add_mapping (primer, 0x3204, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->sampled_x_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sampled_x_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->sampled_x_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3206, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->sampled_y_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sampled_y_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->sampled_y_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3207, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->display_height != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &display_height_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->display_height);
+    mxf_primer_pack_add_mapping (primer, 0x3208, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->display_width != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &display_width_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->display_width);
+    mxf_primer_pack_add_mapping (primer, 0x3209, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->display_x_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &display_x_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->display_x_offset);
+    mxf_primer_pack_add_mapping (primer, 0x320a, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->display_y_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &display_y_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->display_y_offset);
+    mxf_primer_pack_add_mapping (primer, 0x320b, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->display_f2_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &display_f2_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->display_f2_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3217, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->aspect_ratio.n != 0 && self->aspect_ratio.d != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &aspect_ratio_ul, 16);
+    t->size = 8;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->aspect_ratio.n);
+    GST_WRITE_UINT32_BE (t->data + 4, self->aspect_ratio.d);
+    mxf_primer_pack_add_mapping (primer, 0x320e, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->active_format_descriptor != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &active_format_descriptor_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->active_format_descriptor);
+    mxf_primer_pack_add_mapping (primer, 0x3218, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->video_line_map[0] != 0 || self->video_line_map[1] != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &video_line_map_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT64_BE (t->data, self->video_line_map[0]);
+    GST_WRITE_UINT64_BE (t->data + 8, self->video_line_map[1]);
+    mxf_primer_pack_add_mapping (primer, 0x320d, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->alpha_transparency != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &alpha_transparency_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->alpha_transparency);
+    mxf_primer_pack_add_mapping (primer, 0x320f, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_ul_is_zero (&self->capture_gamma)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &capture_gamma_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->capture_gamma, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3210, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->image_alignment_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &image_alignment_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->image_alignment_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3211, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->image_start_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &image_start_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->image_start_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3213, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->image_end_offset != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &image_end_offset_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->image_end_offset);
+    mxf_primer_pack_add_mapping (primer, 0x3214, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->field_dominance != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &field_dominance_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->field_dominance);
+    mxf_primer_pack_add_mapping (primer, 0x3212, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_ul_is_zero (&self->picture_essence_coding)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &picture_essence_coding_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->picture_essence_coding, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3201, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
     mxf_metadata_generic_picture_essence_descriptor_init
     (MXFMetadataGenericPictureEssenceDescriptor * self)
@@ -3588,6 +5249,8 @@ static void
       MXF_QUARK (GENERIC_PICTURE_ESSENCE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_generic_picture_essence_descriptor_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_generic_picture_essence_descriptor_write_tags;
   metadata_class->type = 0x0127;
 }
 
@@ -3641,6 +5304,63 @@ void mxf_metadata_generic_picture_essence_descriptor_set_caps
       par_n, par_d, NULL);
 }
 
+static gint
+gst_greatest_common_divisor (gint a, gint b)
+{
+  while (b != 0) {
+    int temp = a;
+
+    a = b;
+    b = temp % b;
+  }
+
+  return ABS (a);
+}
+
+void mxf_metadata_generic_picture_essence_descriptor_from_caps
+    (MXFMetadataGenericPictureEssenceDescriptor * self, GstCaps * caps)
+{
+  gint par_n, par_d, gcd;
+  gint width, height;
+  gint fps_n, fps_d;
+  MXFMetadataFileDescriptor *f = (MXFMetadataFileDescriptor *) self;
+  GstStructure *s;
+
+  g_return_if_fail (MXF_IS_METADATA_GENERIC_PICTURE_ESSENCE_DESCRIPTOR (self));
+  g_return_if_fail (GST_IS_CAPS (caps));
+
+  s = gst_caps_get_structure (caps, 0);
+
+  if (!gst_structure_get_fraction (s, "framerate", &fps_n, &fps_d)) {
+    GST_ERROR ("Invalid framerate");
+    return;
+  }
+  f->sample_rate.n = fps_n;
+  f->sample_rate.d = fps_d;
+
+  if (!gst_structure_get_int (s, "width", &width) ||
+      !gst_structure_get_int (s, "height", &height)) {
+    GST_ERROR ("Invalid width/height");
+    return;
+  }
+
+  self->stored_width = width;
+  self->stored_height = height;
+
+  if (!gst_structure_get_fraction (s, "pixel-aspect-ratio", &par_n, &par_d)) {
+    par_n = 1;
+    par_d = 1;
+  }
+
+  self->aspect_ratio.n = par_n * width;
+  self->aspect_ratio.d = par_d * height;
+  gcd =
+      gst_greatest_common_divisor (self->aspect_ratio.n, self->aspect_ratio.d);
+  self->aspect_ratio.n /= gcd;
+  self->aspect_ratio.d /= gcd;
+}
+
+
 G_DEFINE_TYPE (MXFMetadataGenericSoundEssenceDescriptor,
     mxf_metadata_generic_sound_essence_descriptor,
     MXF_TYPE_METADATA_FILE_DESCRIPTOR);
@@ -3770,12 +5490,147 @@ mxf_metadata_generic_sound_essence_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_generic_sound_essence_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataGenericSoundEssenceDescriptor *self =
+      MXF_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_generic_sound_essence_descriptor_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 audio_sampling_rate_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x02, 0x03, 0x01, 0x01, 0x01, 0x00, 0x00
+  };
+  static const guint8 locked_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x04, 0x02, 0x03, 0x01, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 audio_ref_level_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x02, 0x01, 0x01, 0x03, 0x00, 0x00, 0x00
+  };
+  static const guint8 electro_spatial_formulation_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x02, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 channel_count_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x02, 0x01, 0x01, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 quantization_bits_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x04, 0x02, 0x03, 0x03, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 dial_norm_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x02, 0x07, 0x01, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 sound_essence_compression_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x02, 0x04, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+
+  if (self->audio_sampling_rate.d && self->audio_sampling_rate.n) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &audio_sampling_rate_ul, 16);
+    t->size = 8;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->audio_sampling_rate.n);
+    GST_WRITE_UINT32_BE (t->data + 4, self->audio_sampling_rate.d);
+    mxf_primer_pack_add_mapping (primer, 0x3d03, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  t = g_slice_new0 (MXFLocalTag);
+  memcpy (&t->key, &locked_ul, 16);
+  t->size = 1;
+  t->data = g_slice_alloc (t->size);
+  t->g_slice = TRUE;
+  GST_WRITE_UINT8 (t->data, (self->locked) ? 1 : 0);
+  mxf_primer_pack_add_mapping (primer, 0x3d02, &t->key);
+  ret = g_list_prepend (ret, t);
+
+  if (self->audio_ref_level) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &audio_ref_level_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->audio_ref_level);
+    mxf_primer_pack_add_mapping (primer, 0x3d04, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->electro_spatial_formulation != 255) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &electro_spatial_formulation_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->electro_spatial_formulation);
+    mxf_primer_pack_add_mapping (primer, 0x3d05, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->channel_count) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &channel_count_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->channel_count);
+    mxf_primer_pack_add_mapping (primer, 0x3d07, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->quantization_bits) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &quantization_bits_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->quantization_bits);
+    mxf_primer_pack_add_mapping (primer, 0x3d01, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->dial_norm != 0) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &dial_norm_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->dial_norm);
+    mxf_primer_pack_add_mapping (primer, 0x3d0c, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (!mxf_ul_is_zero (&self->sound_essence_compression)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sound_essence_compression_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->sound_essence_compression, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3d06, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
     mxf_metadata_generic_sound_essence_descriptor_init
     (MXFMetadataGenericSoundEssenceDescriptor * self)
 {
   self->audio_sampling_rate.n = 48000;
   self->audio_sampling_rate.d = 1;
+  self->electro_spatial_formulation = 255;
 }
 
 static void
@@ -3791,6 +5646,8 @@ static void
       MXF_QUARK (GENERIC_SOUND_ESSENCE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_generic_sound_essence_descriptor_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_generic_sound_essence_descriptor_write_tags;
   metadata_class->type = 0x0142;
 }
 
@@ -3817,6 +5674,33 @@ void mxf_metadata_generic_sound_essence_descriptor_set_caps
   }
 }
 
+void mxf_metadata_generic_sound_essence_descriptor_from_caps
+    (MXFMetadataGenericSoundEssenceDescriptor * self, GstCaps * caps)
+{
+  gint rate;
+  gint channels;
+  GstStructure *s;
+
+  g_return_if_fail (MXF_IS_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR (self));
+  g_return_if_fail (GST_IS_CAPS (caps));
+
+  s = gst_caps_get_structure (caps, 0);
+
+  if (!gst_structure_get_int (s, "rate", &rate)) {
+    GST_WARNING ("No samplerate");
+  } else {
+    self->audio_sampling_rate.n = rate;
+    self->audio_sampling_rate.d = 1;
+  }
+
+  if (!gst_structure_get_int (s, "channels", &channels)) {
+    GST_WARNING ("No channels");
+  } else {
+    self->channel_count = channels;
+  }
+}
+
+
 G_DEFINE_TYPE (MXFMetadataCDCIPictureEssenceDescriptor,
     mxf_metadata_cdci_picture_essence_descriptor,
     MXF_TYPE_METADATA_GENERIC_PICTURE_ESSENCE_DESCRIPTOR);
@@ -3933,7 +5817,7 @@ mxf_metadata_cdci_picture_essence_descriptor_to_structure (MXFMetadataBase * m)
     gst_structure_id_set (ret, MXF_QUARK (VERTICAL_SUBSAMPLING), G_TYPE_UINT,
         self->vertical_subsampling, NULL);
 
-  if (self->color_siting != 0)
+  if (self->color_siting != 255)
     gst_structure_id_set (ret, MXF_QUARK (COLOR_SITING), G_TYPE_UCHAR,
         self->color_siting, NULL);
 
@@ -3963,11 +5847,176 @@ mxf_metadata_cdci_picture_essence_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_cdci_picture_essence_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataCDCIPictureEssenceDescriptor *self =
+      MXF_METADATA_CDCI_PICTURE_ESSENCE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_cdci_picture_essence_descriptor_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 component_depth_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x05, 0x03, 0x0A, 0x00, 0x00, 0x00
+  };
+  static const guint8 horizontal_subsampling_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x05, 0x00, 0x00, 0x00
+  };
+  static const guint8 vertical_subsampling_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x05, 0x01, 0x10, 0x00, 0x00, 0x00
+  };
+  static const guint8 color_siting_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x01, 0x06, 0x00, 0x00, 0x00
+  };
+  static const guint8 reversed_byte_order_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x03, 0x01, 0x02, 0x01, 0x0A, 0x00, 0x00, 0x00
+  };
+  static const guint8 padding_bits_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x18, 0x01, 0x04, 0x00, 0x00, 0x00, 0x00
+  };
+  static const guint8 alpha_sample_depth_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x05, 0x03, 0x07, 0x00, 0x00, 0x00
+  };
+  static const guint8 black_ref_level_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x03, 0x03, 0x00, 0x00, 0x00
+  };
+  static const guint8 white_ref_level_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x04, 0x01, 0x05, 0x03, 0x04, 0x00, 0x00, 0x00
+  };
+  static const guint8 color_range_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x05, 0x03, 0x05, 0x00, 0x00, 0x00
+  };
+
+  if (self->component_depth) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &component_depth_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->component_depth);
+    mxf_primer_pack_add_mapping (primer, 0x3301, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->horizontal_subsampling) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &horizontal_subsampling_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->horizontal_subsampling);
+    mxf_primer_pack_add_mapping (primer, 0x3302, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->vertical_subsampling) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &vertical_subsampling_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->vertical_subsampling);
+    mxf_primer_pack_add_mapping (primer, 0x3308, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->color_siting != 0xff) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &color_siting_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->color_siting);
+    mxf_primer_pack_add_mapping (primer, 0x3303, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->reversed_byte_order) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &reversed_byte_order_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, (self->reversed_byte_order) ? 1 : 0);
+    mxf_primer_pack_add_mapping (primer, 0x330b, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->padding_bits) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &padding_bits_ul, 16);
+    t->size = 2;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT16_BE (t->data, self->padding_bits);
+    mxf_primer_pack_add_mapping (primer, 0x3307, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->alpha_sample_depth) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &alpha_sample_depth_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->alpha_sample_depth);
+    mxf_primer_pack_add_mapping (primer, 0x3309, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->black_ref_level) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &black_ref_level_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->black_ref_level);
+    mxf_primer_pack_add_mapping (primer, 0x3304, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->white_ref_level) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &white_ref_level_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->white_ref_level);
+    mxf_primer_pack_add_mapping (primer, 0x3305, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->color_range) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &color_range_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->color_range);
+    mxf_primer_pack_add_mapping (primer, 0x3306, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
     mxf_metadata_cdci_picture_essence_descriptor_init
     (MXFMetadataCDCIPictureEssenceDescriptor * self)
 {
-
+  self->color_siting = 0xff;
 }
 
 static void
@@ -3982,6 +6031,8 @@ static void
   metadata_base_class->name_quark = MXF_QUARK (CDCI_PICTURE_ESSENCE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_cdci_picture_essence_descriptor_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_cdci_picture_essence_descriptor_write_tags;
   metadata_class->type = 0x0128;
 }
 
@@ -4138,6 +6189,112 @@ mxf_metadata_rgba_picture_essence_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_rgba_picture_essence_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataRGBAPictureEssenceDescriptor *self =
+      MXF_METADATA_RGBA_PICTURE_ESSENCE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_rgba_picture_essence_descriptor_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 component_max_ref_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x05, 0x03, 0x0B, 0x00, 0x00, 0x00
+  };
+  static const guint8 component_min_ref_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x05, 0x03, 0x0C, 0x00, 0x00, 0x00
+  };
+  static const guint8 alpha_max_ref_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x05, 0x03, 0x0D, 0x00, 0x00, 0x00
+  };
+  static const guint8 alpha_min_ref_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x05, 0x03, 0x0E, 0x00, 0x00, 0x00
+  };
+  static const guint8 scanning_direction_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,
+    0x04, 0x01, 0x04, 0x04, 0x01, 0x00, 0x00, 0x00
+  };
+  static const guint8 pixel_layout_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x04, 0x01, 0x05, 0x03, 0x06, 0x00, 0x00, 0x00
+  };
+
+  if (self->component_max_ref != 255) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &component_max_ref_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->component_max_ref);
+    mxf_primer_pack_add_mapping (primer, 0x3406, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->component_min_ref) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &component_min_ref_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->component_min_ref);
+    mxf_primer_pack_add_mapping (primer, 0x3407, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->alpha_max_ref != 255) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &alpha_max_ref_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->alpha_max_ref);
+    mxf_primer_pack_add_mapping (primer, 0x3408, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->alpha_min_ref) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &alpha_min_ref_ul, 16);
+    t->size = 4;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->alpha_min_ref);
+    mxf_primer_pack_add_mapping (primer, 0x3409, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->scanning_direction) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &scanning_direction_ul, 16);
+    t->size = 1;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT8 (t->data, self->scanning_direction);
+    mxf_primer_pack_add_mapping (primer, 0x3405, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  if (self->pixel_layout) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &pixel_layout_ul, 16);
+    t->size = 2 * self->n_pixel_layout + 2;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, self->pixel_layout, self->n_pixel_layout * 2);
+    mxf_primer_pack_add_mapping (primer, 0x3401, &t->key);
+    ret = g_list_prepend (ret, t);
+
+  }
+
+  return ret;
+}
+
 static void
     mxf_metadata_rgba_picture_essence_descriptor_init
     (MXFMetadataRGBAPictureEssenceDescriptor * self)
@@ -4161,6 +6318,8 @@ static void
   metadata_base_class->name_quark = MXF_QUARK (RGBA_PICTURE_ESSENCE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_rgba_picture_essence_descriptor_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_rgba_picture_essence_descriptor_write_tags;
   metadata_class->type = 0x0129;
 }
 
@@ -4227,6 +6386,36 @@ mxf_metadata_generic_data_essence_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_generic_data_essence_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataGenericDataEssenceDescriptor *self =
+      MXF_METADATA_GENERIC_DATA_ESSENCE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_generic_data_essence_descriptor_parent_class)->write_tags
+      (m, primer);
+  MXFLocalTag *t;
+  static const guint8 data_essence_coding_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x03,
+    0x04, 0x03, 0x03, 0x02, 0x00, 0x00, 0x00, 0x00
+  };
+
+  if (!mxf_ul_is_zero (&self->data_essence_coding)) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &data_essence_coding_ul, 16);
+    t->size = 16;
+    t->data = g_slice_alloc (t->size);
+    t->g_slice = TRUE;
+    memcpy (t->data, &self->data_essence_coding, 16);
+    mxf_primer_pack_add_mapping (primer, 0x3e01, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
     mxf_metadata_generic_data_essence_descriptor_init
     (MXFMetadataGenericDataEssenceDescriptor * self)
@@ -4246,6 +6435,8 @@ static void
   metadata_base_class->name_quark = MXF_QUARK (GENERIC_DATA_ESSENCE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_generic_data_essence_descriptor_to_structure;
+  metadata_base_class->write_tags =
+      mxf_metadata_generic_data_essence_descriptor_write_tags;
   metadata_class->type = 0x0143;
 }
 
@@ -4391,6 +6582,44 @@ mxf_metadata_multiple_descriptor_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_multiple_descriptor_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataMultipleDescriptor *self = MXF_METADATA_MULTIPLE_DESCRIPTOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_multiple_descriptor_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 sub_descriptors_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x04,
+    0x06, 0x01, 0x01, 0x04, 0x06, 0x0B, 0x00, 0x00
+  };
+
+  if (self->sub_descriptors) {
+    guint i;
+
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &sub_descriptors_ul, 16);
+    t->size = 8 + 16 * self->n_sub_descriptors;
+    t->data = g_slice_alloc0 (t->size);
+    t->g_slice = TRUE;
+    GST_WRITE_UINT32_BE (t->data, self->n_sub_descriptors);
+    GST_WRITE_UINT32_BE (t->data + 4, 16);
+    for (i = 0; i < self->n_sub_descriptors; i++) {
+      if (!self->sub_descriptors[i])
+        continue;
+
+      memcpy (t->data + 8 + 16 * i,
+          &MXF_METADATA_BASE (self->sub_descriptors[i])->instance_uid, 16);
+    }
+    mxf_primer_pack_add_mapping (primer, 0x3f01, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_multiple_descriptor_init (MXFMetadataMultipleDescriptor * self)
 {
@@ -4411,6 +6640,7 @@ mxf_metadata_multiple_descriptor_class_init (MXFMetadataMultipleDescriptorClass
   metadata_base_class->name_quark = MXF_QUARK (MULTIPLE_DESCRIPTOR);
   metadata_base_class->to_structure =
       mxf_metadata_multiple_descriptor_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_multiple_descriptor_write_tags;
   metadata_class->type = 0x0144;
 }
 
@@ -4480,6 +6710,31 @@ mxf_metadata_text_locator_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_text_locator_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataTextLocator *self = MXF_METADATA_TEXT_LOCATOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_text_locator_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 locator_name_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
+    0x01, 0x04, 0x01, 0x02, 0x01, 0x00, 0x00, 0x00
+  };
+
+  if (self->locator_name) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &locator_name_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->locator_name, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x4101, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_text_locator_init (MXFMetadataTextLocator * self)
 {
@@ -4497,6 +6752,7 @@ mxf_metadata_text_locator_class_init (MXFMetadataTextLocatorClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_text_locator_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (TEXT_LOCATOR);
   metadata_base_class->to_structure = mxf_metadata_text_locator_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_text_locator_write_tags;
   metadata_class->type = 0x0133;
 }
 
@@ -4553,6 +6809,31 @@ mxf_metadata_network_locator_to_structure (MXFMetadataBase * m)
   return ret;
 }
 
+static GList *
+mxf_metadata_network_locator_write_tags (MXFMetadataBase * m,
+    MXFPrimerPack * primer)
+{
+  MXFMetadataNetworkLocator *self = MXF_METADATA_NETWORK_LOCATOR (m);
+  GList *ret =
+      MXF_METADATA_BASE_CLASS
+      (mxf_metadata_network_locator_parent_class)->write_tags (m, primer);
+  MXFLocalTag *t;
+  static const guint8 url_string_ul[] = {
+    0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x01, 0x02, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00
+  };
+
+  if (self->url_string) {
+    t = g_slice_new0 (MXFLocalTag);
+    memcpy (&t->key, &url_string_ul, 16);
+    t->data = mxf_utf8_to_utf16 (self->url_string, &t->size);
+    mxf_primer_pack_add_mapping (primer, 0x4001, &t->key);
+    ret = g_list_prepend (ret, t);
+  }
+
+  return ret;
+}
+
 static void
 mxf_metadata_network_locator_init (MXFMetadataNetworkLocator * self)
 {
@@ -4569,6 +6850,7 @@ mxf_metadata_network_locator_class_init (MXFMetadataNetworkLocatorClass * klass)
   metadata_base_class->handle_tag = mxf_metadata_network_locator_handle_tag;
   metadata_base_class->name_quark = MXF_QUARK (NETWORK_LOCATOR);
   metadata_base_class->to_structure = mxf_metadata_network_locator_to_structure;
+  metadata_base_class->write_tags = mxf_metadata_network_locator_write_tags;
   metadata_class->type = 0x0133;
 }
 
diff --git a/gst/mxf/mxfmetadata.h b/gst/mxf/mxfmetadata.h
index 635c6e02..a29b5834 100644
--- a/gst/mxf/mxfmetadata.h
+++ b/gst/mxf/mxfmetadata.h
@@ -386,6 +386,7 @@ struct _MXFMetadataBaseClass {
   gboolean (*handle_tag) (MXFMetadataBase *self, MXFPrimerPack *primer, guint16 tag, const guint8 *tag_data, guint tag_size);
   gboolean (*resolve) (MXFMetadataBase *self, GHashTable *metadata);
   GstStructure * (*to_structure) (MXFMetadataBase *self);
+  GList * (*write_tags) (MXFMetadataBase *self, MXFPrimerPack *primer);
 
   GQuark name_quark;
 };
@@ -751,15 +752,20 @@ struct _MXFDescriptiveMetadataFrameworkInterface {
 gboolean mxf_metadata_base_parse (MXFMetadataBase *self, MXFPrimerPack *primer, const guint8 *data, guint size);
 gboolean mxf_metadata_base_resolve (MXFMetadataBase *self, GHashTable *metadata);
 GstStructure * mxf_metadata_base_to_structure (MXFMetadataBase *self);
+GstBuffer * mxf_metadata_base_to_buffer (MXFMetadataBase *self, MXFPrimerPack *primer);
 
 MXFMetadata *mxf_metadata_new (guint16 type, MXFPrimerPack *primer, guint64 offset, const guint8 *data, guint size);
 void mxf_metadata_register (GType type);
 void mxf_metadata_init_types (void);
 
 MXFMetadataTrackType mxf_metadata_track_identifier_parse (const MXFUL * track_identifier);
+const MXFUL * mxf_metadata_track_identifier_get (MXFMetadataTrackType type);
 
 void mxf_metadata_generic_picture_essence_descriptor_set_caps (MXFMetadataGenericPictureEssenceDescriptor * self, GstCaps * caps);
+void mxf_metadata_generic_picture_essence_descriptor_from_caps (MXFMetadataGenericPictureEssenceDescriptor * self, GstCaps * caps);
+
 void mxf_metadata_generic_sound_essence_descriptor_set_caps (MXFMetadataGenericSoundEssenceDescriptor * self, GstCaps * caps);
+void mxf_metadata_generic_sound_essence_descriptor_from_caps (MXFMetadataGenericSoundEssenceDescriptor * self, GstCaps * caps);
 
 void mxf_descriptive_metadata_register (guint8 scheme, GType *types);
 MXFDescriptiveMetadata * mxf_descriptive_metadata_new (guint8 scheme, guint32 type, MXFPrimerPack * primer, guint64 offset, const guint8 * data, guint size);
diff --git a/gst/mxf/mxfmux.c b/gst/mxf/mxfmux.c
new file mode 100644
index 00000000..0cec37ee
--- /dev/null
+++ b/gst/mxf/mxfmux.c
@@ -0,0 +1,1327 @@
+/* GStreamer
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <math.h>
+#include <string.h>
+
+#include "mxfmux.h"
+
+#ifdef HAVE_SYS_UTSNAME_H
+#include <sys/utsname.h>
+#endif
+
+GST_DEBUG_CATEGORY_STATIC (mxfmux_debug);
+#define GST_CAT_DEFAULT mxfmux_debug
+
+static GstStaticPadTemplate src_templ = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("application/mxf")
+    );
+
+enum
+{
+  PROP_0
+};
+
+GST_BOILERPLATE (GstMXFMux, gst_mxf_mux, GstElement, GST_TYPE_ELEMENT);
+
+static void gst_mxf_mux_finalize (GObject * object);
+static void gst_mxf_mux_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+static void gst_mxf_mux_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+
+static GstFlowReturn gst_mxf_mux_collected (GstCollectPads * pads,
+    gpointer user_data);
+
+static gboolean gst_mxf_mux_handle_src_event (GstPad * pad, GstEvent * event);
+static GstPad *gst_mxf_mux_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * name);
+static void gst_mxf_mux_release_pad (GstElement * element, GstPad * pad);
+
+static GstStateChangeReturn
+gst_mxf_mux_change_state (GstElement * element, GstStateChange transition);
+
+static void gst_mxf_mux_reset (GstMXFMux * mux);
+
+static GstFlowReturn
+gst_mxf_mux_push (GstMXFMux * mux, GstBuffer * buf)
+{
+  guint size = GST_BUFFER_SIZE (buf);
+  GstFlowReturn ret;
+
+  gst_buffer_set_caps (buf, GST_PAD_CAPS (mux->srcpad));
+  ret = gst_pad_push (mux->srcpad, buf);
+  mux->offset += size;
+
+  return ret;
+}
+
+static void
+gst_mxf_mux_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+  const GstPadTemplate **p;
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_templ));
+
+  p = mxf_essence_element_writer_get_pad_templates ();
+  while (p && *p) {
+    gst_element_class_add_pad_template (element_class,
+        (GstPadTemplate *) gst_object_ref (GST_OBJECT (*p)));
+    p++;
+  }
+
+  gst_element_class_set_details_simple (element_class, "MXF muxer",
+      "Codec/Muxer",
+      "Muxes video/audio streams into a MXF stream",
+      "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
+}
+
+static void
+gst_mxf_mux_class_init (GstMXFMuxClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  GST_DEBUG_CATEGORY_INIT (mxfmux_debug, "mxfmux", 0, "MXF muxer");
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  gobject_class->finalize = gst_mxf_mux_finalize;
+  gobject_class->set_property = gst_mxf_mux_set_property;
+  gobject_class->get_property = gst_mxf_mux_get_property;
+
+  gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_mxf_mux_change_state);
+  gstelement_class->request_new_pad =
+      GST_DEBUG_FUNCPTR (gst_mxf_mux_request_new_pad);
+  gstelement_class->release_pad = GST_DEBUG_FUNCPTR (gst_mxf_mux_release_pad);
+}
+
+static void
+gst_mxf_mux_init (GstMXFMux * mux, GstMXFMuxClass * g_class)
+{
+  GstCaps *caps;
+
+  mux->srcpad = gst_pad_new_from_static_template (&src_templ, "src");
+  gst_pad_set_event_function (mux->srcpad, gst_mxf_mux_handle_src_event);
+  caps = gst_caps_new_simple ("application/mxf", NULL);
+  gst_pad_set_caps (mux->srcpad, caps);
+  gst_caps_unref (caps);
+  gst_element_add_pad (GST_ELEMENT (mux), mux->srcpad);
+
+  mux->collect = gst_collect_pads_new ();
+  gst_collect_pads_set_function (mux->collect,
+      (GstCollectPadsFunction) GST_DEBUG_FUNCPTR (gst_mxf_mux_collected), mux);
+
+  gst_mxf_mux_reset (mux);
+}
+
+static void
+gst_mxf_mux_finalize (GObject * object)
+{
+  GstMXFMux *mux = GST_MXF_MUX (object);
+
+  gst_mxf_mux_reset (mux);
+
+  if (mux->metadata) {
+    g_hash_table_destroy (mux->metadata);
+    mux->metadata = NULL;
+  }
+
+  gst_object_unref (mux->collect);
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gst_mxf_mux_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+  //GstMXFMux *mux = GST_MXF_MUX (object);
+
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_mxf_mux_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  //GstMXFMux *mux = GST_MXF_MUX (object);
+
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_mxf_mux_reset (GstMXFMux * mux)
+{
+  GSList *sl;
+
+  while ((sl = mux->collect->data) != NULL) {
+    GstMXFMuxPad *cpad = (GstMXFMuxPad *) sl->data;
+
+    gst_object_unref (cpad->adapter);
+    g_free (cpad->mapping_data);
+
+    gst_collect_pads_remove_pad (mux->collect, cpad->collect.pad);
+  }
+
+  mux->state = GST_MXF_MUX_STATE_HEADER;
+  mux->n_pads = 0;
+
+  if (mux->metadata) {
+    g_hash_table_destroy (mux->metadata);
+    mux->preface = NULL;
+  }
+  mux->metadata = mxf_metadata_hash_table_new ();
+
+  mxf_partition_pack_reset (&mux->partition);
+  mxf_primer_pack_reset (&mux->primer);
+  memset (&mux->min_edit_rate, 0, sizeof (MXFFraction));
+  mux->last_gc_timestamp = 0;
+  mux->last_gc_position = 0;
+  mux->offset = 0;
+}
+
+static gboolean
+gst_mxf_mux_handle_src_event (GstPad * pad, GstEvent * event)
+{
+  GstEventType type;
+
+  type = event ? GST_EVENT_TYPE (event) : GST_EVENT_UNKNOWN;
+
+  switch (type) {
+    case GST_EVENT_SEEK:
+      /* disable seeking for now */
+      return FALSE;
+    default:
+      break;
+  }
+
+  return gst_pad_event_default (pad, event);
+}
+
+static gboolean
+gst_mxf_mux_handle_sink_event (GstPad * pad, GstEvent * event)
+{
+  GstMXFMux *mux = GST_MXF_MUX (gst_pad_get_parent (pad));
+  gboolean ret = TRUE;
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_TAG:
+      /* TODO: do something with the tags */
+      break;
+    case GST_EVENT_NEWSEGMENT:
+      /* We don't support NEWSEGMENT events */
+      ret = FALSE;
+      gst_event_unref (event);
+      break;
+    default:
+      break;
+  }
+
+  /* now GstCollectPads can take care of the rest, e.g. EOS */
+  if (ret)
+    ret = mux->collect_event (pad, event);
+  gst_object_unref (mux);
+
+  return ret;
+}
+
+static gboolean
+gst_mxf_mux_setcaps (GstPad * pad, GstCaps * caps)
+{
+  GstMXFMux *mux = GST_MXF_MUX (gst_pad_get_parent (pad));
+  GstMXFMuxPad *cpad = (GstMXFMuxPad *) gst_pad_get_element_private (pad);
+  gboolean ret = TRUE;
+  MXFUL d_instance_uid = { {0,} };
+  MXFMetadataFileDescriptor *old_descriptor = cpad->descriptor;
+
+  if (old_descriptor) {
+    memcpy (&d_instance_uid, &MXF_METADATA_BASE (old_descriptor)->instance_uid,
+        16);
+    cpad->descriptor = NULL;
+    g_free (cpad->mapping_data);
+    cpad->mapping_data = NULL;
+  }
+
+  cpad->descriptor =
+      cpad->writer->get_descriptor (gst_pad_get_pad_template (pad), caps,
+      &cpad->write_func, &cpad->mapping_data);
+
+  if (!cpad->descriptor) {
+    GST_ERROR_OBJECT (mux,
+        "Couldn't get descriptor for pad '%s' with caps %" GST_PTR_FORMAT,
+        GST_PAD_NAME (pad), caps);
+    gst_object_unref (mux);
+    return FALSE;
+  }
+
+  if (mxf_ul_is_zero (&d_instance_uid))
+    mxf_ul_set (&d_instance_uid, mux->metadata);
+
+  memcpy (&MXF_METADATA_BASE (cpad->descriptor)->instance_uid, &d_instance_uid,
+      16);
+
+  g_hash_table_replace (mux->metadata,
+      &MXF_METADATA_BASE (cpad->descriptor)->instance_uid, cpad->descriptor);
+
+  if (old_descriptor) {
+    if (mux->preface && mux->preface->content_storage &&
+        mux->preface->content_storage->packages) {
+      guint i, j;
+
+      for (i = 0; i < mux->preface->content_storage->n_packages; i++) {
+        MXFMetadataSourcePackage *package;
+
+        if (!MXF_IS_METADATA_SOURCE_PACKAGE (mux->preface->
+                content_storage->packages[i]))
+          continue;
+
+        package =
+            MXF_METADATA_SOURCE_PACKAGE (mux->preface->
+            content_storage->packages[i]);
+
+        if (!package->descriptor)
+          continue;
+
+        if (MXF_IS_METADATA_MULTIPLE_DESCRIPTOR (package->descriptor)) {
+          MXFMetadataMultipleDescriptor *tmp =
+              MXF_METADATA_MULTIPLE_DESCRIPTOR (package->descriptor);
+
+          for (j = 0; j < tmp->n_sub_descriptors; j++) {
+            if (tmp->sub_descriptors[j] ==
+                MXF_METADATA_GENERIC_DESCRIPTOR (old_descriptor)) {
+              tmp->sub_descriptors[j] =
+                  MXF_METADATA_GENERIC_DESCRIPTOR (cpad->descriptor);
+              memcpy (&tmp->sub_descriptors_uids[j], &d_instance_uid, 16);
+            }
+          }
+        } else if (package->descriptor ==
+            MXF_METADATA_GENERIC_DESCRIPTOR (old_descriptor)) {
+          package->descriptor =
+              MXF_METADATA_GENERIC_DESCRIPTOR (cpad->descriptor);
+          memcpy (&package->descriptor_uid, &d_instance_uid, 16);
+        }
+      }
+    }
+  }
+
+  gst_object_unref (mux);
+
+  return ret;
+}
+
+static GstPad *
+gst_mxf_mux_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * pad_name)
+{
+  GstMXFMux *mux = GST_MXF_MUX (element);
+  GstMXFMuxPad *cpad;
+  GstPad *pad = NULL;
+  guint pad_number;
+  gchar *name = NULL;
+  const MXFEssenceElementWriter *writer;
+
+  if (mux->state != GST_MXF_MUX_STATE_HEADER) {
+    GST_WARNING_OBJECT (mux, "Can't request pads after writing header");
+    return NULL;
+  }
+
+  writer = mxf_essence_element_writer_find (templ);
+  if (!writer) {
+    GST_ERROR_OBJECT (mux, "Not our template");
+    return NULL;
+  }
+
+  pad_number = g_atomic_int_exchange_and_add ((gint *) & mux->n_pads, 1);
+  name = g_strdup_printf (GST_PAD_TEMPLATE_NAME_TEMPLATE (templ), pad_number);
+
+  pad = gst_pad_new_from_template (templ, name);
+  g_free (name);
+  cpad = (GstMXFMuxPad *)
+      gst_collect_pads_add_pad (mux->collect, pad, sizeof (GstMXFMuxPad));
+  cpad->last_timestamp = 0;
+  cpad->adapter = gst_adapter_new ();
+  cpad->writer = writer;
+
+  /* FIXME: hacked way to override/extend the event function of
+   * GstCollectPads; because it sets its own event function giving the
+   * element no access to events.
+   */
+  mux->collect_event = (GstPadEventFunction) GST_PAD_EVENTFUNC (pad);
+  gst_pad_set_event_function (pad,
+      GST_DEBUG_FUNCPTR (gst_mxf_mux_handle_sink_event));
+
+  gst_pad_set_setcaps_function (pad, gst_mxf_mux_setcaps);
+  gst_pad_use_fixed_caps (pad);
+  gst_pad_set_active (pad, TRUE);
+  gst_element_add_pad (element, pad);
+
+  return pad;
+}
+
+static void
+gst_mxf_mux_release_pad (GstElement * element, GstPad * pad)
+{
+  GstMXFMux *mux = GST_MXF_MUX (GST_PAD_PARENT (pad));
+  GstMXFMuxPad *cpad = (GstMXFMuxPad *) gst_pad_get_element_private (pad);
+
+  gst_object_unref (cpad->adapter);
+  g_free (cpad->mapping_data);
+
+  gst_collect_pads_remove_pad (mux->collect, pad);
+  gst_element_remove_pad (element, pad);
+}
+
+static GstFlowReturn
+gst_mxf_mux_create_metadata (GstMXFMux * mux)
+{
+  GstFlowReturn ret = GST_FLOW_OK;
+  GSList *l;
+  GArray *tmp;
+
+  for (l = mux->collect->data; l; l = l->next) {
+    GstMXFMuxPad *cpad = l->data;
+
+    if (cpad->writer->update_descriptor)
+      cpad->writer->update_descriptor (cpad->descriptor,
+          GST_PAD_CAPS (cpad->collect.pad), cpad->mapping_data,
+          cpad->collect.buffer);
+  }
+
+  /* Preface */
+  mux->preface =
+      (MXFMetadataPreface *) gst_mini_object_new (MXF_TYPE_METADATA_PREFACE);
+  mxf_ul_set (&MXF_METADATA_BASE (mux->preface)->instance_uid, mux->metadata);
+  g_hash_table_insert (mux->metadata,
+      &MXF_METADATA_BASE (mux->preface)->instance_uid, mux->preface);
+
+  mxf_timestamp_set_now (&mux->preface->last_modified_date);
+  mux->preface->version = 258;
+  mux->preface->object_model_version = 1;
+
+  mxf_op_set_generalized (&mux->preface->operational_pattern, MXF_OP_1a, TRUE,
+      TRUE, FALSE);
+
+  tmp = g_array_new (FALSE, FALSE, sizeof (MXFUL));
+  for (l = mux->collect->data; l; l = l->next) {
+    GstMXFMuxPad *cpad = l->data;
+
+    if (!cpad || !cpad->descriptor ||
+        mxf_ul_is_zero (&cpad->descriptor->essence_container))
+      return GST_FLOW_ERROR;
+
+    g_array_append_val (tmp, cpad->descriptor->essence_container);
+  }
+  mux->preface->n_essence_containers = tmp->len;
+  mux->preface->essence_containers = (MXFUL *) g_array_free (tmp, FALSE);
+
+  /* This will later be used as UID for the material package */
+  mxf_ul_set (&mux->preface->primary_package_uid, mux->metadata);
+
+  /* Identifications */
+  {
+    MXFMetadataIdentification *identification;
+    static const guint8 gst_uid[] = {
+      0xe5, 0xde, 0xcd, 0x04, 0x24, 0x90, 0x69, 0x18,
+      0x8a, 0xc9, 0xb5, 0xd7, 0x02, 0x58, 0x46, 0x78
+    };
+    guint major, minor, micro, nano;
+
+    mux->preface->n_identifications = 1;
+    mux->preface->identifications = g_new0 (MXFMetadataIdentification *, 1);
+    identification = mux->preface->identifications[0] =
+        (MXFMetadataIdentification *)
+        gst_mini_object_new (MXF_TYPE_METADATA_IDENTIFICATION);
+
+    mxf_ul_set (&MXF_METADATA_BASE (identification)->instance_uid,
+        mux->metadata);
+    g_hash_table_insert (mux->metadata,
+        &MXF_METADATA_BASE (identification)->instance_uid, identification);
+
+    mxf_ul_set (&identification->this_generation_uid, NULL);
+
+    identification->company_name = g_strdup ("GStreamer");
+    identification->product_name = g_strdup ("GStreamer Multimedia Framework");
+
+    gst_version (&major, &minor, &micro, &nano);
+    identification->product_version.major = major;
+    identification->product_version.minor = minor;
+    identification->product_version.patch = micro;
+    identification->product_version.build = nano;
+    identification->product_version.release =
+        (nano == 0) ? 1 : (nano == 1) ? 2 : 4;
+
+    identification->version_string =
+        g_strdup_printf ("%u.%u.%u.%u", major, minor, micro, nano);
+    memcpy (&identification->product_uid, &gst_uid, 16);
+
+    memcpy (&identification->modification_date,
+        &mux->preface->last_modified_date, sizeof (MXFTimestamp));
+    memcpy (&identification->toolkit_version, &identification->product_version,
+        sizeof (MXFProductVersion));
+
+#ifdef HAVE_SYS_UTSNAME_H
+    {
+      struct utsname sys_details;
+
+      if (uname (&sys_details) == 0) {
+        identification->platform = g_strdup_printf ("%s %s %s",
+            sys_details.sysname, sys_details.release, sys_details.machine);
+      }
+    }
+#endif
+
+#if defined(G_OS_WIN32)
+    if (identification->platform == NULL)
+      identification->platform = g_strdup ("Microsoft Windows");
+#elif defined(G_OS_BEOS)
+    if (identification->platform == NULL)
+      identification->platform = g_strdup ("BEOS");
+#elif defined(G_OS_UNIX)
+    if (identification->platform == NULL)
+      identification->platform = g_strdup ("Unix");
+#endif
+  }
+
+  /* Content storage */
+  {
+    MXFMetadataContentStorage *cstorage;
+    guint i;
+
+    cstorage = mux->preface->content_storage = (MXFMetadataContentStorage *)
+        gst_mini_object_new (MXF_TYPE_METADATA_CONTENT_STORAGE);
+    mxf_ul_set (&MXF_METADATA_BASE (cstorage)->instance_uid, mux->metadata);
+    g_hash_table_insert (mux->metadata,
+        &MXF_METADATA_BASE (cstorage)->instance_uid, cstorage);
+
+    cstorage->n_packages = 2;
+    cstorage->packages = g_new (MXFMetadataGenericPackage *, 2);
+
+    /* Source package */
+    {
+      MXFMetadataSourcePackage *p;
+
+      cstorage->packages[1] = (MXFMetadataGenericPackage *)
+          gst_mini_object_new (MXF_TYPE_METADATA_SOURCE_PACKAGE);
+      mxf_ul_set (&MXF_METADATA_BASE (cstorage->packages[1])->instance_uid,
+          mux->metadata);
+      g_hash_table_insert (mux->metadata,
+          &MXF_METADATA_BASE (cstorage->packages[1])->instance_uid,
+          cstorage->packages[1]);
+      p = (MXFMetadataSourcePackage *) cstorage->packages[1];
+
+      mxf_umid_set (&p->parent.package_uid);
+      p->parent.name = g_strdup ("Source package");
+      memcpy (&p->parent.package_creation_date,
+          &mux->preface->last_modified_date, sizeof (MXFTimestamp));
+      memcpy (&p->parent.package_modified_date,
+          &mux->preface->last_modified_date, sizeof (MXFTimestamp));
+
+      p->parent.n_tracks = g_slist_length (mux->collect->data);
+      p->parent.tracks = g_new (MXFMetadataTrack *, p->parent.n_tracks);
+
+      if (p->parent.n_tracks > 1) {
+        MXFMetadataMultipleDescriptor *d;
+
+        p->descriptor = (MXFMetadataGenericDescriptor *)
+            gst_mini_object_new (MXF_TYPE_METADATA_MULTIPLE_DESCRIPTOR);
+        d = (MXFMetadataMultipleDescriptor *) p->descriptor;
+        d->n_sub_descriptors = p->parent.n_tracks;
+        d->sub_descriptors =
+            g_new (MXFMetadataGenericDescriptor *, p->parent.n_tracks);
+
+        mxf_ul_set (&MXF_METADATA_BASE (d)->instance_uid, mux->metadata);
+        g_hash_table_insert (mux->metadata,
+            &MXF_METADATA_BASE (d)->instance_uid, d);
+      }
+
+      /* Tracks */
+      {
+        guint n = 0;
+
+        /* Essence tracks */
+        for (l = mux->collect->data; l; l = l->next) {
+          GstMXFMuxPad *cpad = l->data;
+          MXFMetadataTimelineTrack *track;
+          MXFMetadataSequence *sequence;
+          MXFMetadataSourceClip *clip;
+
+          p->parent.tracks[n] = (MXFMetadataTrack *)
+              gst_mini_object_new (MXF_TYPE_METADATA_TIMELINE_TRACK);
+          track = (MXFMetadataTimelineTrack *) p->parent.tracks[n];
+          mxf_ul_set (&MXF_METADATA_BASE (track)->instance_uid, mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (track)->instance_uid, track);
+
+          track->parent.track_id = n + 1;
+          track->parent.track_number =
+              cpad->writer->get_track_number_template (cpad->descriptor,
+              GST_PAD_CAPS (cpad->collect.pad), cpad->mapping_data);
+
+          cpad->writer->get_edit_rate (cpad->descriptor,
+              GST_PAD_CAPS (cpad->collect.pad), cpad->mapping_data,
+              cpad->collect.buffer, p, track, &track->edit_rate);
+
+          sequence = track->parent.sequence = (MXFMetadataSequence *)
+              gst_mini_object_new (MXF_TYPE_METADATA_SEQUENCE);
+          mxf_ul_set (&MXF_METADATA_BASE (sequence)->instance_uid,
+              mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (sequence)->instance_uid, sequence);
+
+          memcpy (&sequence->data_definition, &cpad->writer->data_definition,
+              16);
+
+          sequence->n_structural_components = 1;
+          sequence->structural_components =
+              g_new (MXFMetadataStructuralComponent *, 1);
+
+          clip = (MXFMetadataSourceClip *)
+              gst_mini_object_new (MXF_TYPE_METADATA_SOURCE_CLIP);
+          sequence->structural_components[0] =
+              (MXFMetadataStructuralComponent *) clip;
+          mxf_ul_set (&MXF_METADATA_BASE (clip)->instance_uid, mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (clip)->instance_uid, clip);
+
+          memcpy (&clip->parent.data_definition, &sequence->data_definition,
+              16);
+          clip->start_position = 0;
+
+          cpad->source_package = p;
+          cpad->source_track = track;
+          cpad->descriptor->linked_track_id = n + 1;
+          if (p->parent.n_tracks == 1) {
+            p->descriptor = (MXFMetadataGenericDescriptor *) cpad->descriptor;
+          } else {
+            MXF_METADATA_MULTIPLE_DESCRIPTOR (p->
+                descriptor)->sub_descriptors[n] =
+                (MXFMetadataGenericDescriptor *) cpad->descriptor;
+          }
+
+          n++;
+        }
+      }
+    }
+
+    /* Material package */
+    {
+      MXFMetadataMaterialPackage *p;
+      MXFFraction min_edit_rate = { 0, 0 };
+      gdouble min_edit_rate_d = G_MAXDOUBLE;
+
+      cstorage->packages[0] = (MXFMetadataGenericPackage *)
+          gst_mini_object_new (MXF_TYPE_METADATA_MATERIAL_PACKAGE);
+      memcpy (&MXF_METADATA_BASE (cstorage->packages[0])->instance_uid,
+          &mux->preface->primary_package_uid, 16);
+      g_hash_table_insert (mux->metadata,
+          &MXF_METADATA_BASE (cstorage->packages[0])->instance_uid,
+          cstorage->packages[0]);
+      p = (MXFMetadataMaterialPackage *) cstorage->packages[0];
+
+      mxf_umid_set (&p->package_uid);
+      p->name = g_strdup ("Material package");
+      memcpy (&p->package_creation_date, &mux->preface->last_modified_date,
+          sizeof (MXFTimestamp));
+      memcpy (&p->package_modified_date, &mux->preface->last_modified_date,
+          sizeof (MXFTimestamp));
+
+      p->n_tracks = g_slist_length (mux->collect->data) + 1;
+      p->tracks = g_new (MXFMetadataTrack *, p->n_tracks);
+
+      /* Tracks */
+      {
+        guint n;
+
+        n = 1;
+        /* Essence tracks */
+        for (l = mux->collect->data; l; l = l->next) {
+          GstMXFMuxPad *cpad = l->data;
+          MXFMetadataSourcePackage *source_package;
+          MXFMetadataTimelineTrack *track, *source_track;
+          MXFMetadataSequence *sequence;
+          MXFMetadataSourceClip *clip;
+
+          source_package = MXF_METADATA_SOURCE_PACKAGE (cstorage->packages[1]);
+          source_track =
+              MXF_METADATA_TIMELINE_TRACK (source_package->parent.tracks[n -
+                  1]);
+
+          p->tracks[n] = (MXFMetadataTrack *)
+              gst_mini_object_new (MXF_TYPE_METADATA_TIMELINE_TRACK);
+          track = (MXFMetadataTimelineTrack *) p->tracks[n];
+          mxf_ul_set (&MXF_METADATA_BASE (track)->instance_uid, mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (track)->instance_uid, track);
+
+          track->parent.track_id = n + 1;
+          track->parent.track_number = 0;
+
+          cpad->writer->get_edit_rate (cpad->descriptor,
+              GST_PAD_CAPS (cpad->collect.pad), cpad->mapping_data,
+              cpad->collect.buffer, source_package, source_track,
+              &track->edit_rate);
+
+          if (track->edit_rate.n != source_track->edit_rate.n ||
+              track->edit_rate.d != source_track->edit_rate.d) {
+            memcpy (&source_track->edit_rate, &track->edit_rate,
+                sizeof (MXFFraction));
+          }
+
+          if (min_edit_rate_d >
+              ((gdouble) track->edit_rate.n) / ((gdouble) track->edit_rate.d)) {
+            min_edit_rate_d =
+                ((gdouble) track->edit_rate.n) / ((gdouble) track->edit_rate.d);
+            memcpy (&min_edit_rate, &track->edit_rate, sizeof (MXFFraction));
+          }
+
+          sequence = track->parent.sequence = (MXFMetadataSequence *)
+              gst_mini_object_new (MXF_TYPE_METADATA_SEQUENCE);
+          mxf_ul_set (&MXF_METADATA_BASE (sequence)->instance_uid,
+              mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (sequence)->instance_uid, sequence);
+
+          memcpy (&sequence->data_definition, &cpad->writer->data_definition,
+              16);
+          sequence->n_structural_components = 1;
+          sequence->structural_components =
+              g_new (MXFMetadataStructuralComponent *, 1);
+
+          clip = (MXFMetadataSourceClip *)
+              gst_mini_object_new (MXF_TYPE_METADATA_SOURCE_CLIP);
+          sequence->structural_components[0] =
+              (MXFMetadataStructuralComponent *) clip;
+          mxf_ul_set (&MXF_METADATA_BASE (clip)->instance_uid, mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (clip)->instance_uid, clip);
+
+          memcpy (&clip->parent.data_definition, &sequence->data_definition,
+              16);
+          clip->start_position = 0;
+
+          memcpy (&clip->source_package_id, &cstorage->packages[1]->package_uid,
+              32);
+          clip->source_track_id = n;
+
+          n++;
+        }
+
+        n = 0;
+        /* Timecode track */
+        {
+          MXFMetadataTimelineTrack *track;
+          MXFMetadataSequence *sequence;
+          MXFMetadataTimecodeComponent *component;
+
+          p->tracks[n] = (MXFMetadataTrack *)
+              gst_mini_object_new (MXF_TYPE_METADATA_TIMELINE_TRACK);
+          track = (MXFMetadataTimelineTrack *) p->tracks[n];
+          mxf_ul_set (&MXF_METADATA_BASE (track)->instance_uid, mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (track)->instance_uid, track);
+
+          track->parent.track_id = n + 1;
+          track->parent.track_number = 0;
+          track->parent.track_name = g_strdup ("Timecode track");
+          /* FIXME: Is this correct? */
+          memcpy (&track->edit_rate, &min_edit_rate, sizeof (MXFFraction));
+
+          sequence = track->parent.sequence = (MXFMetadataSequence *)
+              gst_mini_object_new (MXF_TYPE_METADATA_SEQUENCE);
+          mxf_ul_set (&MXF_METADATA_BASE (sequence)->instance_uid,
+              mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (sequence)->instance_uid, sequence);
+
+          memcpy (&sequence->data_definition,
+              mxf_metadata_track_identifier_get
+              (MXF_METADATA_TRACK_TIMECODE_12M_INACTIVE), 16);
+
+          sequence->n_structural_components = 1;
+          sequence->structural_components =
+              g_new (MXFMetadataStructuralComponent *, 1);
+
+          component = (MXFMetadataTimecodeComponent *)
+              gst_mini_object_new (MXF_TYPE_METADATA_TIMECODE_COMPONENT);
+          sequence->structural_components[0] =
+              (MXFMetadataStructuralComponent *) component;
+          mxf_ul_set (&MXF_METADATA_BASE (component)->instance_uid,
+              mux->metadata);
+          g_hash_table_insert (mux->metadata,
+              &MXF_METADATA_BASE (component)->instance_uid, component);
+
+          memcpy (&component->parent.data_definition,
+              &sequence->data_definition, 16);
+
+          component->start_timecode = 0;
+          component->rounded_timecode_base =
+              (((gdouble) track->edit_rate.n) / ((gdouble) track->edit_rate.d) +
+              0.5);
+          /* TODO: drop frame */
+        }
+
+        memcpy (&mux->min_edit_rate, &min_edit_rate, sizeof (MXFFraction));
+      }
+    }
+
+    for (i = 0; i < cstorage->packages[1]->n_tracks; i++) {
+      MXFMetadataTrack *track = cstorage->packages[1]->tracks[i];
+      guint j;
+      guint32 templ;
+      guint8 n_type, n;
+
+      if ((track->track_number & 0x00ff00ff) != 0)
+        continue;
+
+      templ = track->track_number;
+      n_type = 0;
+
+      for (j = 0; j < cstorage->packages[1]->n_tracks; j++) {
+        MXFMetadataTrack *tmp = cstorage->packages[1]->tracks[j];
+
+        if (tmp->track_number == templ) {
+          n_type++;
+        }
+      }
+
+      n = 0;
+      for (j = 0; j < cstorage->packages[1]->n_tracks; j++) {
+        MXFMetadataTrack *tmp = cstorage->packages[1]->tracks[j];
+
+        if (tmp->track_number == templ) {
+          n++;
+          tmp->track_number |= (n_type << 16) | (n);
+        }
+      }
+    }
+
+    cstorage->n_essence_container_data = 1;
+    cstorage->essence_container_data =
+        g_new (MXFMetadataEssenceContainerData *, 1);
+    cstorage->essence_container_data[0] = (MXFMetadataEssenceContainerData *)
+        gst_mini_object_new (MXF_TYPE_METADATA_ESSENCE_CONTAINER_DATA);
+    mxf_ul_set (&MXF_METADATA_BASE (cstorage->
+            essence_container_data[0])->instance_uid, mux->metadata);
+    g_hash_table_insert (mux->metadata,
+        &MXF_METADATA_BASE (cstorage->essence_container_data[0])->instance_uid,
+        cstorage->essence_container_data[0]);
+
+    cstorage->essence_container_data[0]->linked_package =
+        MXF_METADATA_SOURCE_PACKAGE (cstorage->packages[1]);
+    cstorage->essence_container_data[0]->index_sid = 0;
+    cstorage->essence_container_data[0]->body_sid = 1;
+  }
+
+  return ret;
+}
+
+static GstFlowReturn
+gst_mxf_mux_create_header_partition_pack (GstMXFMux * mux)
+{
+  GSList *l;
+  guint i = 0;
+
+  mxf_partition_pack_reset (&mux->partition);
+  mux->partition.type = MXF_PARTITION_PACK_HEADER;
+  mux->partition.closed = mux->partition.complete = FALSE;
+  mux->partition.major_version = 0x0001;
+  mux->partition.minor_version = 0x0002;
+  mux->partition.kag_size = 0;
+  mux->partition.this_partition = 0;
+  mux->partition.prev_partition = 0;
+  mux->partition.footer_partition = 0;
+  mux->partition.header_byte_count = 0;
+  mux->partition.index_byte_count = 0;
+  mux->partition.index_sid = 0;
+  mux->partition.body_offset = 0;
+  mux->partition.body_sid = 0;
+
+  memcpy (&mux->partition.operational_pattern,
+      &mux->preface->operational_pattern, 16);
+
+  mux->partition.n_essence_containers = g_slist_length (mux->collect->data);
+  mux->partition.essence_containers =
+      g_new0 (MXFUL, mux->partition.n_essence_containers);
+
+  for (l = mux->collect->data; l; l = l->next) {
+    GstMXFMuxPad *cpad = l->data;
+    guint j;
+
+    for (j = 0; j < i; j++) {
+      if (mxf_ul_is_equal (&cpad->descriptor->essence_container,
+              &mux->partition.essence_containers[j]))
+        continue;
+    }
+
+    memcpy (&mux->partition.essence_containers[i],
+        &cpad->descriptor->essence_container, 16);
+    i++;
+  }
+  mux->partition.n_essence_containers = i;
+
+  return GST_FLOW_OK;
+}
+
+static GstFlowReturn
+gst_mxf_mux_write_header_metadata (GstMXFMux * mux)
+{
+  GstFlowReturn ret = GST_FLOW_OK;
+  GstBuffer *buf;
+  GList *buffers = NULL;
+#if GLIB_CHECK_VERSION (2, 16, 0)
+  GHashTableIter iter;
+#else
+  GList *values;
+#endif
+  MXFMetadataBase *m;
+  GList *l;
+  guint64 header_byte_count = 0;
+
+  buf =
+      mxf_metadata_base_to_buffer (MXF_METADATA_BASE (mux->preface),
+      &mux->primer);
+  header_byte_count += GST_BUFFER_SIZE (buf);
+  buffers = g_list_prepend (buffers, buf);
+
+#if GLIB_CHECK_VERSION (2, 16, 0)
+  g_hash_table_iter_init (&iter, mux->metadata);
+  while (g_hash_table_iter_next (&iter, NULL, (gpointer) & m)) {
+#else
+  values = g_hash_table_get_values (mux->metadata);
+  for (l = values; l; l = l->next) {
+    m = l->data;
+#endif
+    buf = mxf_metadata_base_to_buffer (m, &mux->primer);
+    header_byte_count += GST_BUFFER_SIZE (buf);
+    buffers = g_list_prepend (buffers, buf);
+  }
+
+#if !GLIB_CHECK_VERSION (2, 16, 0)
+  g_list_free (value);
+#endif
+
+  buffers = g_list_reverse (buffers);
+  buf = mxf_primer_pack_to_buffer (&mux->primer);
+  header_byte_count += GST_BUFFER_SIZE (buf);
+  buffers = g_list_prepend (buffers, buf);
+
+  mux->partition.header_byte_count = header_byte_count;
+  buf = mxf_partition_pack_to_buffer (&mux->partition);
+  if ((ret = gst_mxf_mux_push (mux, buf)) != GST_FLOW_OK) {
+    GST_ERROR_OBJECT (mux, "Failed pushing partition: %s",
+        gst_flow_get_name (ret));
+    g_list_foreach (buffers, (GFunc) gst_mini_object_unref, NULL);
+    g_list_free (buffers);
+    return ret;
+  }
+
+  for (l = buffers; l; l = l->next) {
+    buf = l->data;
+    l->data = NULL;
+    if ((ret = gst_mxf_mux_push (mux, buf)) != GST_FLOW_OK) {
+      GST_ERROR_OBJECT (mux, "Failed pushing buffer: %s",
+          gst_flow_get_name (ret));
+      g_list_foreach (buffers, (GFunc) gst_mini_object_unref, NULL);
+      g_list_free (buffers);
+      return ret;
+    }
+  }
+
+  g_list_free (buffers);
+
+  return ret;
+}
+
+static const guint8 _gc_essence_element_ul[] = {
+  0x06, 0x0e, 0x2b, 0x34, 0x01, 0x02, 0x01, 0x00,
+  0x0d, 0x01, 0x03, 0x01, 0x00, 0x00, 0x00, 0x00
+};
+
+static GstFlowReturn
+gst_mxf_mux_handle_buffer (GstMXFMux * mux, GstMXFMuxPad * cpad)
+{
+  GstBuffer *buf = gst_collect_pads_pop (mux->collect, &cpad->collect);
+  GstBuffer *outbuf = NULL;
+  GstBuffer *packet;
+  GstFlowReturn ret = GST_FLOW_OK;
+  guint8 slen, ber[9];
+
+  if ((ret =
+          cpad->write_func (buf, GST_PAD_CAPS (cpad->collect.pad),
+              cpad->mapping_data, cpad->adapter, &outbuf,
+              FALSE) != GST_FLOW_OK)) {
+    GST_ERROR_OBJECT (mux, "Failed handling buffer for track %u",
+        cpad->source_track->parent.track_id);
+    return ret;
+  }
+
+  buf = outbuf;
+  if (buf == NULL)
+    return ret;
+
+  slen = mxf_ber_encode_size (GST_BUFFER_SIZE (buf), ber);
+  packet = gst_buffer_new_and_alloc (16 + slen + GST_BUFFER_SIZE (buf));
+  memcpy (GST_BUFFER_DATA (packet), _gc_essence_element_ul, 16);
+  GST_BUFFER_DATA (packet)[7] = cpad->descriptor->essence_container.u[7];
+  GST_WRITE_UINT32_BE (&GST_BUFFER_DATA (packet)[12],
+      cpad->source_track->parent.track_number);
+  memcpy (&GST_BUFFER_DATA (packet)[16], ber, slen);
+  memcpy (&GST_BUFFER_DATA (packet)[16 + slen], GST_BUFFER_DATA (buf),
+      GST_BUFFER_SIZE (buf));
+  gst_buffer_unref (buf);
+
+  if ((ret = gst_mxf_mux_push (mux, packet)) != GST_FLOW_OK) {
+    GST_ERROR_OBJECT (mux, "Failed pushing buffer for track %u",
+        cpad->source_track->parent.track_id);
+    return ret;
+  }
+
+  cpad->pos++;
+  cpad->last_timestamp =
+      gst_util_uint64_scale (GST_SECOND * cpad->pos,
+      cpad->source_track->edit_rate.d, cpad->source_track->edit_rate.n);
+
+  return ret;
+}
+
+static GstFlowReturn
+gst_mxf_mux_write_body_partition (GstMXFMux * mux)
+{
+  GstBuffer *buf;
+
+  mux->partition.type = MXF_PARTITION_PACK_BODY;
+  mux->partition.closed = mux->partition.complete = FALSE;
+  mux->partition.major_version = 0x0001;
+  mux->partition.minor_version = 0x0002;
+  mux->partition.kag_size = 0;
+  mux->partition.this_partition = mux->offset;
+  mux->partition.prev_partition = 0;
+  mux->partition.footer_partition = 0;
+  mux->partition.header_byte_count = 0;
+  mux->partition.index_byte_count = 0;
+  mux->partition.index_sid = 0;
+  mux->partition.body_offset = 0;
+  mux->partition.body_sid =
+      mux->preface->content_storage->essence_container_data[0]->body_sid;
+
+  buf = mxf_partition_pack_to_buffer (&mux->partition);
+  return gst_mxf_mux_push (mux, buf);
+}
+
+static GstFlowReturn
+gst_mxf_mux_handle_eos (GstMXFMux * mux)
+{
+  GSList *l;
+  GstBuffer *packet, *buf;
+
+  for (l = mux->collect->data; l; l = l->next) {
+    GstMXFMuxPad *cpad = l->data;
+    GstFlowReturn ret;
+    guint i;
+
+    buf = NULL;
+    cpad->write_func (NULL, GST_PAD_CAPS (cpad->collect.pad),
+        cpad->mapping_data, cpad->adapter, &buf, TRUE);
+
+    if (buf) {
+      guint8 slen, ber[9];
+
+      slen = mxf_ber_encode_size (GST_BUFFER_SIZE (buf), ber);
+      packet = gst_buffer_new_and_alloc (16 + slen + GST_BUFFER_SIZE (buf));
+      memcpy (GST_BUFFER_DATA (packet), _gc_essence_element_ul, 16);
+      GST_BUFFER_DATA (packet)[7] = cpad->descriptor->essence_container.u[7];
+      GST_WRITE_UINT32_BE (&GST_BUFFER_DATA (packet)[12],
+          cpad->source_track->parent.track_number);
+      memcpy (&GST_BUFFER_DATA (packet)[16], ber, slen);
+      memcpy (&GST_BUFFER_DATA (packet)[16 + slen], GST_BUFFER_DATA (buf),
+          GST_BUFFER_SIZE (buf));
+      gst_buffer_unref (buf);
+
+      ret = gst_mxf_mux_push (mux, packet);
+      if (ret != GST_FLOW_OK) {
+        GST_WARNING_OBJECT (mux, "Failed handling EOS for track %u",
+            cpad->source_track->parent.track_id);
+      }
+      cpad->pos++;
+    }
+
+    /* Update durations */
+    cpad->source_track->parent.sequence->duration = cpad->pos;
+    MXF_METADATA_SOURCE_CLIP (cpad->source_track->parent.
+        sequence->structural_components[0])->parent.duration = cpad->pos;
+    for (i = 0; i < mux->preface->content_storage->packages[0]->n_tracks; i++) {
+      MXFMetadataTimelineTrack *track;
+
+      if (!MXF_IS_METADATA_TIMELINE_TRACK (mux->preface->
+              content_storage->packages[0]->tracks[i])
+          || !MXF_IS_METADATA_SOURCE_CLIP (mux->preface->
+              content_storage->packages[0]->tracks[i]->sequence->
+              structural_components[0]))
+        continue;
+
+      track =
+          MXF_METADATA_TIMELINE_TRACK (mux->preface->
+          content_storage->packages[0]->tracks[i]);
+      if (MXF_METADATA_SOURCE_CLIP (track->parent.
+              sequence->structural_components[0])->source_track_id ==
+          cpad->source_track->parent.track_id) {
+        track->parent.sequence->structural_components[0]->duration = cpad->pos;
+        track->parent.sequence->duration = cpad->pos;
+      }
+    }
+  }
+
+  /* Update timecode track duration */
+  {
+    MXFMetadataTimelineTrack *track =
+        MXF_METADATA_TIMELINE_TRACK (mux->preface->
+        content_storage->packages[0]->tracks[0]);
+    MXFMetadataSequence *sequence = track->parent.sequence;
+    MXFMetadataTimecodeComponent *component =
+        MXF_METADATA_TIMECODE_COMPONENT (sequence->structural_components[0]);
+
+    sequence->duration = mux->last_gc_position;
+    component->parent.duration = mux->last_gc_position;
+  }
+
+  {
+    guint64 body_partition = mux->partition.this_partition;
+    guint32 body_sid = mux->partition.body_sid;
+    guint64 footer_partition = mux->offset;
+    GArray *rip;
+    GstFlowReturn ret;
+    MXFRandomIndexPackEntry entry;
+
+    mux->partition.type = MXF_PARTITION_PACK_FOOTER;
+    mux->partition.closed = TRUE;
+    mux->partition.complete = TRUE;
+    mux->partition.major_version = 0x0001;
+    mux->partition.minor_version = 0x0002;
+    mux->partition.kag_size = 0;
+    mux->partition.this_partition = mux->offset;
+    mux->partition.prev_partition = body_partition;
+    mux->partition.footer_partition = mux->offset;
+    mux->partition.header_byte_count = 0;
+    mux->partition.index_byte_count = 0;
+    mux->partition.index_sid = 0;
+    mux->partition.body_offset = 0;
+    mux->partition.body_sid = 0;
+
+    gst_mxf_mux_write_header_metadata (mux);
+
+    rip = g_array_sized_new (FALSE, FALSE, sizeof (MXFRandomIndexPackEntry), 3);
+    entry.offset = 0;
+    entry.body_sid = 0;
+    g_array_append_val (rip, entry);
+    entry.offset = body_partition;
+    entry.body_sid = body_sid;
+    g_array_append_val (rip, entry);
+    entry.offset = footer_partition;
+    entry.body_sid = 0;
+    g_array_append_val (rip, entry);
+
+    packet = mxf_random_index_pack_to_buffer (rip);
+    if ((ret = gst_mxf_mux_push (mux, packet)) != GST_FLOW_OK) {
+      GST_ERROR_OBJECT (mux, "Failed pushing random index pack");
+    }
+    g_array_free (rip, TRUE);
+
+    /* Rewrite header partition with updated values */
+    if (gst_pad_push_event (mux->srcpad,
+            gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, 0, -1,
+                0))) {
+      mux->offset = 0;
+      mux->partition.type = MXF_PARTITION_PACK_HEADER;
+      mux->partition.closed = TRUE;
+      mux->partition.complete = TRUE;
+      mux->partition.major_version = 0x0001;
+      mux->partition.minor_version = 0x0002;
+      mux->partition.kag_size = 0;
+      mux->partition.this_partition = 0;
+      mux->partition.prev_partition = footer_partition;
+      mux->partition.footer_partition = footer_partition;
+      mux->partition.header_byte_count = 0;
+      mux->partition.index_byte_count = 0;
+      mux->partition.index_sid = 0;
+      mux->partition.body_offset = 0;
+      mux->partition.body_sid = 0;
+
+      ret = gst_mxf_mux_write_header_metadata (mux);
+      if (ret != GST_FLOW_OK) {
+        GST_ERROR_OBJECT (mux, "Rewriting header partition failed");
+        return ret;
+      }
+    } else {
+      GST_WARNING_OBJECT (mux, "Can't rewrite header partition");
+    }
+  }
+
+  return GST_FLOW_OK;
+}
+
+static gint
+_sort_mux_pads (gconstpointer a, gconstpointer b)
+{
+  const GstMXFMuxPad *pa = a, *pb = b;
+  MXFMetadataTrackType ta =
+      mxf_metadata_track_identifier_parse (&pa->writer->data_definition);
+  MXFMetadataTrackType tb =
+      mxf_metadata_track_identifier_parse (&pb->writer->data_definition);
+
+  if (ta != tb)
+    return ta - tb;
+
+  return pa->source_track->parent.track_number -
+      pa->source_track->parent.track_number;
+}
+
+static GstFlowReturn
+gst_mxf_mux_collected (GstCollectPads * pads, gpointer user_data)
+{
+  GstMXFMux *mux = GST_MXF_MUX (user_data);
+  GstMXFMuxPad *best = NULL;
+  GstFlowReturn ret;
+  GSList *sl;
+  gboolean eos = TRUE;
+
+  if (mux->state == GST_MXF_MUX_STATE_HEADER) {
+    if (mux->collect->data == NULL) {
+      GST_ELEMENT_ERROR (mux, STREAM, MUX, (NULL),
+          ("No input streams configured"));
+      return GST_FLOW_ERROR;
+    }
+
+    if (gst_pad_push_event (mux->srcpad,
+            gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_BYTES, 0, -1,
+                0))) {
+      if ((ret = gst_mxf_mux_create_metadata (mux)) != GST_FLOW_OK)
+        return ret;
+
+      if ((ret = gst_mxf_mux_create_header_partition_pack (mux)) != GST_FLOW_OK)
+        return ret;
+
+      ret = gst_mxf_mux_write_header_metadata (mux);
+    } else {
+      ret = GST_FLOW_ERROR;
+    }
+
+    if (ret != GST_FLOW_OK)
+      return ret;
+
+    /* Sort pads, we will always write in that order */
+    mux->collect->data = g_slist_sort (mux->collect->data, _sort_mux_pads);
+
+    /* Write body partition */
+    ret = gst_mxf_mux_write_body_partition (mux);
+    if (ret != GST_FLOW_OK)
+      return ret;
+    mux->state = GST_MXF_MUX_STATE_DATA;
+  }
+
+  for (sl = mux->collect->data; sl; sl = sl->next) {
+    GstMXFMuxPad *cpad = sl->data;
+    GstClockTime next_gc_timestamp =
+        gst_util_uint64_scale ((mux->last_gc_position + 1) * GST_SECOND,
+        mux->min_edit_rate.d, mux->min_edit_rate.n);
+
+    if (cpad->collect.abidata.ABI.eos)
+      continue;
+
+    if (cpad->last_timestamp < next_gc_timestamp) {
+      eos = FALSE;
+      best = cpad;
+      break;
+    } else if (eos || !sl->next) {
+      mux->last_gc_position++;
+      mux->last_gc_timestamp = next_gc_timestamp;
+      sl = mux->collect->data;
+    }
+    eos = FALSE;
+  }
+
+  if (!eos && best) {
+    return gst_mxf_mux_handle_buffer (mux, best);
+  } else if (eos) {
+    mux->last_gc_position++;
+    mux->last_gc_timestamp =
+        gst_util_uint64_scale (mux->last_gc_position * GST_SECOND,
+        mux->min_edit_rate.d, mux->min_edit_rate.n);
+    gst_mxf_mux_handle_eos (mux);
+    gst_pad_push_event (mux->srcpad, gst_event_new_eos ());
+    return GST_FLOW_UNEXPECTED;
+  } else {
+    return GST_FLOW_OK;
+  }
+}
+
+static GstStateChangeReturn
+gst_mxf_mux_change_state (GstElement * element, GstStateChange transition)
+{
+  GstStateChangeReturn ret;
+  GstMXFMux *mux = GST_MXF_MUX (element);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      break;
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+      gst_collect_pads_start (mux->collect);
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_collect_pads_stop (mux->collect);
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+      break;
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_mxf_mux_reset (mux);
+      break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
diff --git a/gst/mxf/mxfmux.h b/gst/mxf/mxfmux.h
new file mode 100644
index 00000000..ed35d7cb
--- /dev/null
+++ b/gst/mxf/mxfmux.h
@@ -0,0 +1,100 @@
+/* GStreamer
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __MXF_MUX_H__
+#define __MXF_MUX_H__
+
+#include <gst/gst.h>
+#include <gst/base/gstadapter.h>
+#include <gst/base/gstcollectpads.h>
+
+#include "mxfwrite.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_MXF_MUX \
+  (gst_mxf_mux_get_type ())
+#define GST_MXF_MUX(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_MXF_MUX, GstMXFMux))
+#define GST_MXF_MUX_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_MXF_MUX, GstMXFMuxClass))
+#define GST_IS_MXF_MUX(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_MXF_MUX))
+#define GST_IS_MXF_MUX_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_MXF_MUX))
+
+typedef struct
+{
+  GstCollectData collect;
+
+  guint64 pos;
+  GstClockTime last_timestamp;
+
+  MXFMetadataFileDescriptor *descriptor;
+
+  GstAdapter *adapter;
+
+  gpointer mapping_data;
+  const MXFEssenceElementWriter *writer;
+  MXFEssenceElementWriteFunc write_func;
+
+  MXFMetadataSourcePackage *source_package;
+  MXFMetadataTimelineTrack *source_track;
+} GstMXFMuxPad;
+
+typedef enum
+{
+  GST_MXF_MUX_STATE_HEADER,
+  GST_MXF_MUX_STATE_DATA
+} GstMXFMuxState;
+
+typedef struct _GstMXFMux {
+  GstElement element;
+
+  GstPad *srcpad;
+  GstCollectPads *collect;
+  GstPadEventFunction collect_event;
+
+  GstMXFMuxState state;
+  guint n_pads;
+
+  guint64 offset;
+
+  MXFPartitionPack partition;
+  MXFPrimerPack primer;
+  
+  GHashTable *metadata;
+  MXFMetadataPreface *preface;
+
+  MXFFraction min_edit_rate;
+  guint64 last_gc_position;
+  GstClockTime last_gc_timestamp;
+
+  gchar *application;
+} GstMXFMux;
+
+typedef struct _GstMXFMuxClass {
+  GstElementClass parent;
+} GstMXFMuxClass;
+
+GType gst_mxf_mux_get_type (void);
+
+G_END_DECLS
+
+#endif /* __MXF_MUX_H__ */
diff --git a/gst/mxf/mxfparse.c b/gst/mxf/mxfparse.c
index d4d52312..71d639e4 100644
--- a/gst/mxf/mxfparse.c
+++ b/gst/mxf/mxfparse.c
@@ -469,6 +469,14 @@ mxf_product_version_parse (MXFProductVersion * product_version,
 }
 
 gboolean
+mxf_product_version_is_valid (const MXFProductVersion * version)
+{
+  static const guint8 null[sizeof (MXFProductVersion)] = { 0, };
+
+  return (memcmp (version, &null, sizeof (MXFProductVersion)) == 0);
+}
+
+gboolean
 mxf_ul_array_parse (MXFUL ** array, guint32 * count, const guint8 * data,
     guint size)
 {
@@ -1023,7 +1031,12 @@ mxf_primer_pack_reset (MXFPrimerPack * pack)
 
   if (pack->mappings)
     g_hash_table_destroy (pack->mappings);
+  if (pack->reverse_mappings)
+    g_hash_table_destroy (pack->reverse_mappings);
+
   memset (pack, 0, sizeof (MXFPrimerPack));
+
+  pack->next_free_tag = 0x8000;
 }
 
 /* structural metadata parsing */
@@ -1051,7 +1064,10 @@ mxf_local_tag_parse (const guint8 * data, guint size, guint16 * tag,
 void
 mxf_local_tag_free (MXFLocalTag * tag)
 {
-  g_free (tag->data);
+  if (tag->g_slice)
+    g_slice_free1 (tag->size, tag->data);
+  else
+    g_free (tag->data);
   g_slice_free (MXFLocalTag, tag);
 }
 
@@ -1100,6 +1116,32 @@ mxf_local_tag_add_to_hash_table (const MXFPrimerPack * primer,
   return TRUE;
 }
 
+gboolean
+mxf_local_tag_insert (MXFLocalTag * tag, GHashTable ** hash_table)
+{
+#ifndef GST_DISABLE_GST_DEBUG
+  gchar str[48];
+#endif
+
+  g_return_val_if_fail (tag != NULL, FALSE);
+  g_return_val_if_fail (hash_table != NULL, FALSE);
+
+  if (*hash_table == NULL)
+    *hash_table =
+        g_hash_table_new_full ((GHashFunc) mxf_ul_hash,
+        (GEqualFunc) mxf_ul_is_equal, (GDestroyNotify) NULL,
+        (GDestroyNotify) mxf_local_tag_free);
+
+  g_return_val_if_fail (*hash_table != NULL, FALSE);
+
+  GST_DEBUG ("Adding local tag 0x%04x with UL %s and size %u", tag,
+      mxf_ul_to_string (&tag->key, str), tag->size);
+
+  g_hash_table_insert (*hash_table, &tag->key, tag);
+
+  return TRUE;
+}
+
 static GSList *_mxf_essence_element_handler_registry = NULL;
 
 void
diff --git a/gst/mxf/mxfparse.h b/gst/mxf/mxfparse.h
index 5a5e630e..4e4f7dc1 100644
--- a/gst/mxf/mxfparse.h
+++ b/gst/mxf/mxfparse.h
@@ -72,6 +72,7 @@ gchar * mxf_utf16_to_utf8 (const guint8 * data, guint size);
 
 gboolean mxf_product_version_parse (MXFProductVersion * product_version,
     const guint8 * data, guint size);
+gboolean mxf_product_version_is_valid (const MXFProductVersion *version);
 
 gboolean mxf_fraction_parse (MXFFraction *fraction, const guint8 *data, guint size);
 gdouble mxf_fraction_to_double (const MXFFraction *fraction);
@@ -96,11 +97,12 @@ void mxf_index_table_segment_reset (MXFIndexTableSegment *segment);
 
 gboolean mxf_local_tag_parse (const guint8 * data, guint size, guint16 * tag,
     guint16 * tag_size, const guint8 ** tag_data);
-void gst_mxf_local_tag_free (MXFLocalTag *tag);
+void mxf_local_tag_free (MXFLocalTag *tag);
 
 gboolean mxf_local_tag_add_to_hash_table (const MXFPrimerPack *primer,
   guint16 tag, const guint8 *tag_data, guint16 tag_size,
   GHashTable **hash_table);
+gboolean mxf_local_tag_insert (MXFLocalTag *tag, GHashTable **hash_table);
 
 void mxf_essence_element_handler_register (const MXFEssenceElementHandler *handler);
 const MXFEssenceElementHandler * mxf_essence_element_handler_find (const MXFMetadataTimelineTrack *track);
diff --git a/gst/mxf/mxftypes.h b/gst/mxf/mxftypes.h
index dcbbd28d..f0878597 100644
--- a/gst/mxf/mxftypes.h
+++ b/gst/mxf/mxftypes.h
@@ -65,6 +65,8 @@ typedef struct {
   MXFUL key;
   guint16 size;
   guint8 *data;
+  
+  gboolean g_slice; /* TRUE if data was allocated by GSlice */
 } MXFLocalTag;
 
 /* SMPTE 377M 11.1 */
@@ -114,6 +116,8 @@ typedef struct {
 typedef struct {
   guint64 offset;
   GHashTable *mappings;
+  GHashTable *reverse_mappings;
+  guint16 next_free_tag;
 } MXFPrimerPack;
 
 /* SMPTE 377M 10.2.3 */
diff --git a/gst/mxf/mxfwrite.c b/gst/mxf/mxfwrite.c
new file mode 100644
index 00000000..c2c15bba
--- /dev/null
+++ b/gst/mxf/mxfwrite.c
@@ -0,0 +1,567 @@
+/* GStreamer
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <string.h>
+
+#include "mxfwrite.h"
+
+GST_DEBUG_CATEGORY_EXTERN (mxf_debug);
+#define GST_CAT_DEFAULT mxf_debug
+
+static GList *_essence_element_writer_registry = NULL;
+static GPtrArray *_essence_element_writer_pad_templates = NULL;
+
+void
+mxf_essence_element_writer_register (const MXFEssenceElementWriter * writer)
+{
+  _essence_element_writer_registry =
+      g_list_prepend (_essence_element_writer_registry, (gpointer) writer);
+
+  if (!_essence_element_writer_pad_templates)
+    _essence_element_writer_pad_templates = g_ptr_array_new ();
+
+  if (_essence_element_writer_pad_templates->len > 0 &&
+      g_ptr_array_index (_essence_element_writer_pad_templates,
+          _essence_element_writer_pad_templates->len - 1) == NULL)
+    g_ptr_array_remove_index (_essence_element_writer_pad_templates,
+        _essence_element_writer_pad_templates->len - 1);
+
+  g_ptr_array_add (_essence_element_writer_pad_templates,
+      (gpointer) writer->pad_template);
+}
+
+const GstPadTemplate **
+mxf_essence_element_writer_get_pad_templates (void)
+{
+  if (!_essence_element_writer_pad_templates
+      || _essence_element_writer_pad_templates->len == 0)
+    return NULL;
+
+  if (g_ptr_array_index (_essence_element_writer_pad_templates,
+          _essence_element_writer_pad_templates->len - 1))
+    g_ptr_array_add (_essence_element_writer_pad_templates, NULL);
+
+  return (const GstPadTemplate **) _essence_element_writer_pad_templates->pdata;
+}
+
+const MXFEssenceElementWriter *
+mxf_essence_element_writer_find (const GstPadTemplate * templ)
+{
+  GList *l = _essence_element_writer_registry;
+
+  for (; l; l = l->next) {
+    MXFEssenceElementWriter *writer = l->data;
+
+    if (writer->pad_template == templ)
+      return writer;
+  }
+
+  return NULL;
+}
+
+void
+mxf_ul_set (MXFUL * ul, GHashTable * hashtable)
+{
+  guint i;
+
+next_try:
+  for (i = 0; i < 4; i++)
+    GST_WRITE_UINT32_BE (&ul->u[i * 4], g_random_int ());
+
+  if (hashtable && g_hash_table_lookup_extended (hashtable, ul, NULL, NULL))
+    goto next_try;
+}
+
+void
+mxf_umid_set (MXFUMID * umid)
+{
+  guint i;
+  guint32 tmp;
+
+  /* SMPTE S330M 5.1.1:
+   *    UMID Identifier
+   */
+  umid->u[0] = 0x06;
+  umid->u[1] = 0x0a;
+  umid->u[2] = 0x2b;
+  umid->u[3] = 0x34;
+  umid->u[4] = 0x01;
+  umid->u[5] = 0x01;
+  umid->u[6] = 0x01;
+  umid->u[7] = 0x05;            /* version, see RP210 */
+  umid->u[8] = 0x01;
+  umid->u[9] = 0x01;
+  umid->u[10] = 0x0d;           /* mixed group of components in a single container */
+
+  /* - UUID/UL method for material number
+   * - 24 bit PRG for instance number
+   */
+  umid->u[11] = 0x20 | 0x02;
+
+  /* Length of remaining data */
+  umid->u[12] = 0x13;
+
+  /* Instance number */
+  tmp = g_random_int ();
+  umid->u[13] = (tmp >> 24) & 0xff;
+  umid->u[14] = (tmp >> 16) & 0xff;
+  umid->u[15] = (tmp >> 8) & 0xff;
+
+  /* Material number: ISO UUID Version 4 */
+  for (i = 16; i < 32; i += 4)
+    GST_WRITE_UINT32_BE (&umid->u[i], g_random_int ());
+
+  umid->u[16 + 6] &= 0x0f;
+  umid->u[16 + 6] |= 0x40;
+
+  umid->u[16 + 8] &= 0x3f;
+  umid->u[16 + 8] |= 0x80;
+}
+
+void
+mxf_timestamp_set_now (MXFTimestamp * timestamp)
+{
+  GTimeVal tv;
+  time_t t;
+  struct tm *tm;
+
+#ifdef HAVE_GMTIME_R
+  struct tm tm_;
+#endif
+
+  g_get_current_time (&tv);
+  t = (time_t) tv.tv_sec;
+
+#ifdef HAVE_GMTIME_R
+  tm = gmtime_r (&t, &tm_);
+#else
+  tm = gmtime (&t);
+#endif
+
+  timestamp->year = tm->tm_year + 1900;
+  timestamp->month = tm->tm_mon;
+  timestamp->day = tm->tm_mday;
+  timestamp->hour = tm->tm_hour;
+  timestamp->minute = tm->tm_min;
+  timestamp->second = tm->tm_sec;
+  timestamp->msecond = tv.tv_usec / 1000;
+}
+
+static guint8 mxf_op_identification_ul[] = {
+  0x06, 0x0e, 0x2b, 0x34, 0x04, 0x01, 0x01, 0x01, 0x0d, 0x01, 0x02, 0x01
+};
+
+void
+mxf_op_set_atom (MXFUL * ul, gboolean single_sourceclip,
+    gboolean single_essence_track)
+{
+  memcpy (&ul->u, &mxf_op_identification_ul, 12);
+  ul->u[12] = 0x10;
+  ul->u[13] = 0;
+
+  if (!single_sourceclip)
+    ul->u[13] |= 0x80;
+
+  if (!single_essence_track)
+    ul->u[13] |= 0x40;
+
+  ul->u[14] = 0;
+  ul->u[15] = 0;
+}
+
+void
+mxf_op_set_generalized (MXFUL * ul, MXFOperationalPattern pattern,
+    gboolean internal_essence, gboolean streamable, gboolean single_track)
+{
+  g_return_if_fail (pattern >= MXF_OP_1a);
+
+  memcpy (&ul->u, &mxf_op_identification_ul, 12);
+
+  if (pattern == MXF_OP_1a || pattern == MXF_OP_1b || pattern == MXF_OP_1c)
+    ul->u[12] = 0x01;
+  else if (pattern == MXF_OP_2a || pattern == MXF_OP_2b || pattern == MXF_OP_2c)
+    ul->u[12] = 0x02;
+  else if (pattern == MXF_OP_3a || pattern == MXF_OP_3b || pattern == MXF_OP_3c)
+    ul->u[12] = 0x03;
+
+  if (pattern == MXF_OP_1a || pattern == MXF_OP_2a || pattern == MXF_OP_3a)
+    ul->u[13] = 0x01;
+  else if (pattern == MXF_OP_1b || pattern == MXF_OP_2b || pattern == MXF_OP_3b)
+    ul->u[13] = 0x02;
+  else if (pattern == MXF_OP_1c || pattern == MXF_OP_2c || pattern == MXF_OP_3c)
+    ul->u[13] = 0x02;
+
+  ul->u[14] = 0x80;
+  if (!internal_essence)
+    ul->u[14] |= 0x40;
+  if (!streamable)
+    ul->u[14] |= 0x20;
+  if (!single_track)
+    ul->u[14] |= 0x10;
+
+  ul->u[15] = 0;
+}
+
+static void
+_mxf_mapping_ul_free (MXFUL * ul)
+{
+  g_slice_free (MXFUL, ul);
+}
+
+guint16
+mxf_primer_pack_add_mapping (MXFPrimerPack * primer, guint16 local_tag,
+    const MXFUL * ul)
+{
+  MXFUL *uid;
+#ifndef GST_DISABLE_GST_DEBUG
+  gchar str[48];
+#endif
+
+  if (primer->mappings == NULL) {
+    primer->mappings = g_hash_table_new_full (g_direct_hash, g_direct_equal,
+        (GDestroyNotify) NULL, (GDestroyNotify) _mxf_mapping_ul_free);
+  }
+
+  if (primer->reverse_mappings == NULL) {
+    primer->reverse_mappings = g_hash_table_new_full ((GHashFunc) mxf_ul_hash,
+        (GEqualFunc) mxf_ul_is_equal, (GDestroyNotify) _mxf_mapping_ul_free,
+        (GDestroyNotify) NULL);
+  }
+
+  if (primer->next_free_tag == 0xffff && local_tag == 0) {
+    GST_ERROR ("Used too many dynamic tags");
+    return 0;
+  }
+
+  if (local_tag == 0) {
+    guint16 tmp;
+
+    tmp = GPOINTER_TO_UINT (g_hash_table_lookup (primer->reverse_mappings, ul));
+    if (tmp == 0) {
+      local_tag = primer->next_free_tag;
+      primer->next_free_tag++;
+    }
+  } else {
+    if (g_hash_table_lookup (primer->mappings, GUINT_TO_POINTER (local_tag)))
+      return local_tag;
+  }
+
+  g_assert (local_tag != 0);
+
+  uid = g_slice_new (MXFUL);
+  memcpy (uid, ul, 16);
+
+  GST_DEBUG ("Adding mapping = 0x%04x -> %s", local_tag,
+      mxf_ul_to_string (uid, str));
+  g_hash_table_insert (primer->mappings, GUINT_TO_POINTER (local_tag), uid);
+  uid = g_slice_dup (MXFUL, uid);
+  g_hash_table_insert (primer->reverse_mappings, uid,
+      GUINT_TO_POINTER (local_tag));
+
+  return local_tag;
+}
+
+guint
+mxf_ber_encode_size (guint size, guint8 ber[9])
+{
+  guint8 slen, i;
+  guint8 tmp[8];
+
+  memset (ber, 0, 9);
+
+  if (size <= 127) {
+    ber[0] = size;
+    return 1;
+  } else if (size > G_MAXUINT) {
+    return 0;
+  }
+
+  slen = 0;
+  while (size > 0) {
+    tmp[slen] = size & 0xff;
+    size >>= 8;
+    slen++;
+  }
+
+  ber[0] = 0x80 | slen;
+  for (i = 0; i < slen; i++) {
+    ber[i + 1] = tmp[slen - i - 1];
+  }
+
+  return slen + 1;
+}
+
+void
+mxf_timestamp_write (const MXFTimestamp * timestamp, guint8 * data)
+{
+  GST_WRITE_UINT16_BE (data, timestamp->year);
+  GST_WRITE_UINT8 (data + 2, timestamp->month);
+  GST_WRITE_UINT8 (data + 3, timestamp->day);
+  GST_WRITE_UINT8 (data + 4, timestamp->hour);
+  GST_WRITE_UINT8 (data + 5, timestamp->minute);
+  GST_WRITE_UINT8 (data + 6, timestamp->second);
+  GST_WRITE_UINT8 (data + 7, (timestamp->msecond * 256) / 1000);
+}
+
+guint8 *
+mxf_utf8_to_utf16 (const gchar * str, guint16 * size)
+{
+  guint8 *ret;
+  GError *error = NULL;
+  gsize s;
+
+  g_return_val_if_fail (size != NULL, NULL);
+
+  if (str == NULL) {
+    *size = 0;
+    return NULL;
+  }
+
+  ret = (guint8 *)
+      g_convert_with_fallback (str, -1, "UTF-16BE", "UTF-8", "*", NULL, &s,
+      &error);
+
+  if (ret == NULL) {
+    GST_WARNING ("UTF-16-BE to UTF-8 conversion failed: %s", error->message);
+    g_error_free (error);
+    *size = 0;
+    return NULL;
+  }
+
+  *size = s;
+  return (guint8 *) ret;
+}
+
+void
+mxf_product_version_write (const MXFProductVersion * version, guint8 * data)
+{
+  GST_WRITE_UINT16_BE (data, version->major);
+  GST_WRITE_UINT16_BE (data + 2, version->minor);
+  GST_WRITE_UINT16_BE (data + 4, version->patch);
+  GST_WRITE_UINT16_BE (data + 6, version->build);
+  GST_WRITE_UINT16_BE (data + 8, version->release);
+}
+
+GstBuffer *
+mxf_partition_pack_to_buffer (const MXFPartitionPack * pack)
+{
+  static const guint8 partition_pack_ul[] =
+      { 0x06, 0x0e, 0x2b, 0x34, 0x02, 0x05, 0x01, 0x01,
+    0x0d, 0x01, 0x02, 0x01, 0x01
+  };
+  guint slen;
+  guint8 ber[9];
+  GstBuffer *ret;
+  guint8 *data;
+  guint i;
+  guint size =
+      8 + 16 * pack->n_essence_containers + 16 + 4 + 8 + 4 + 8 + 8 + 8 + 8 + 8 +
+      4 + 2 + 2;
+
+  slen = mxf_ber_encode_size (size, ber);
+
+  ret = gst_buffer_new_and_alloc (16 + slen + size);
+  memcpy (GST_BUFFER_DATA (ret), &partition_pack_ul, 13);
+  if (pack->type == MXF_PARTITION_PACK_HEADER)
+    GST_BUFFER_DATA (ret)[13] = 0x02;
+  else if (pack->type == MXF_PARTITION_PACK_BODY)
+    GST_BUFFER_DATA (ret)[13] = 0x03;
+  else if (pack->type == MXF_PARTITION_PACK_FOOTER)
+    GST_BUFFER_DATA (ret)[13] = 0x04;
+  GST_BUFFER_DATA (ret)[14] = 0;
+  if (pack->complete)
+    GST_BUFFER_DATA (ret)[14] |= 0x02;
+  if (pack->closed)
+    GST_BUFFER_DATA (ret)[14] |= 0x01;
+  GST_BUFFER_DATA (ret)[14] += 1;
+  GST_BUFFER_DATA (ret)[15] = 0;
+  memcpy (GST_BUFFER_DATA (ret) + 16, &ber, slen);
+
+  data = GST_BUFFER_DATA (ret) + 16 + slen;
+
+  GST_WRITE_UINT16_BE (data, pack->major_version);
+  GST_WRITE_UINT16_BE (data + 2, pack->minor_version);
+  data += 4;
+
+  GST_WRITE_UINT32_BE (data, pack->kag_size);
+  data += 4;
+
+  GST_WRITE_UINT64_BE (data, pack->this_partition);
+  data += 8;
+
+  GST_WRITE_UINT64_BE (data, pack->prev_partition);
+  data += 8;
+
+  GST_WRITE_UINT64_BE (data, pack->footer_partition);
+  data += 8;
+
+  GST_WRITE_UINT64_BE (data, pack->header_byte_count);
+  data += 8;
+
+  GST_WRITE_UINT64_BE (data, pack->index_byte_count);
+  data += 8;
+
+  GST_WRITE_UINT32_BE (data, pack->index_sid);
+  data += 4;
+
+  GST_WRITE_UINT64_BE (data, pack->body_offset);
+  data += 8;
+
+  GST_WRITE_UINT32_BE (data, pack->body_sid);
+  data += 4;
+
+  memcpy (data, &pack->operational_pattern, 16);
+  data += 16;
+
+  GST_WRITE_UINT32_BE (data, pack->n_essence_containers);
+  GST_WRITE_UINT32_BE (data + 4, 16);
+  data += 8;
+
+  for (i = 0; i < pack->n_essence_containers; i++)
+    memcpy (data + 16 * i, &pack->essence_containers[i], 16);
+
+  return ret;
+}
+
+GstBuffer *
+mxf_primer_pack_to_buffer (const MXFPrimerPack * pack)
+{
+  static const guint8 primer_pack_ul[] =
+      { 0x06, 0x0e, 0x2b, 0x34, 0x02, 0x05, 0x01, 0x01, 0x0d, 0x01, 0x02, 0x01,
+    0x01, 0x05, 0x01, 0x00
+  };
+  guint slen;
+  guint8 ber[9];
+  GstBuffer *ret;
+  guint n;
+  guint8 *data;
+
+  if (pack->mappings)
+    n = g_hash_table_size (pack->mappings);
+  else
+    n = 0;
+
+  slen = mxf_ber_encode_size (8 + 18 * n, ber);
+
+  ret = gst_buffer_new_and_alloc (16 + slen + 8 + 18 * n);
+  memcpy (GST_BUFFER_DATA (ret), &primer_pack_ul, 16);
+  memcpy (GST_BUFFER_DATA (ret) + 16, &ber, slen);
+
+  data = GST_BUFFER_DATA (ret) + 16 + slen;
+
+  GST_WRITE_UINT32_BE (data, n);
+  GST_WRITE_UINT32_BE (data + 4, 18);
+  data += 8;
+
+  if (pack->mappings) {
+    guint16 local_tag;
+    MXFUL *ul;
+#if GLIB_CHECK_VERSION (2, 16, 0)
+    GHashTableIter iter;
+
+    g_hash_table_iter_init (&iter, pack->mappings);
+#else
+    GList *l, *values;
+
+    keys = g_hash_table_get_keys (pack->mappings);
+#endif
+
+#if GLIB_CHECK_VERSION (2, 16, 0)
+    while (g_hash_table_iter_next (&iter, (gpointer) & local_tag,
+            (gpointer) & ul)) {
+#else
+    for (l = keys l; l = l->next) {
+      local_tag = GPOINTER_TO_GUINT (l->data);
+      ul = g_hash_table_lookup (pack->mappings, GUINT_TO_POINTER (local_tag));
+#endif
+      GST_WRITE_UINT16_BE (data, local_tag);
+      memcpy (data + 2, ul, 16);
+      data += 18;
+    }
+
+#if !GLIB_CHECK_VERSION (2, 16, 0)
+    g_list_free (keys);
+#endif
+  }
+
+  return ret;
+}
+
+GstBuffer *
+mxf_fill_new (guint size)
+{
+  static const guint8 fill_ul[] =
+      { 0x06, 0x0e, 0x2b, 0x34, 0x01, 0x01, 0x01, 0x01,
+    0x03, 0x01, 0x02, 0x10, 0x01, 0x00, 0x00, 0x00
+  };
+  GstBuffer *ret;
+  guint slen;
+  guint8 ber[9];
+
+  slen = mxf_ber_encode_size (size, ber);
+
+  ret = gst_buffer_new_and_alloc (16 + slen + size);
+  memcpy (GST_BUFFER_DATA (ret), &fill_ul, 16);
+  memcpy (GST_BUFFER_DATA (ret) + 16, &ber, slen);
+  memset (GST_BUFFER_DATA (ret) + slen, 0, size);
+
+  return ret;
+}
+
+static const guint8 random_index_pack_ul[] =
+    { 0x06, 0x0e, 0x2b, 0x34, 0x02, 0x05, 0x01, 0x01,
+  0x0d, 0x01, 0x02, 0x01, 0x01, 0x11, 0x01, 0x00
+};
+
+GstBuffer *
+mxf_random_index_pack_to_buffer (const GArray * array)
+{
+  MXFRandomIndexPackEntry *entry;
+  guint i;
+  GstBuffer *ret;
+  guint8 slen, ber[9];
+  guint size;
+  guint8 *data;
+
+  if (array->len == 0)
+    return NULL;
+
+  size = array->len * 12 + 4;
+  slen = mxf_ber_encode_size (size, ber);
+  ret = gst_buffer_new_and_alloc (16 + slen + size);
+  memcpy (GST_BUFFER_DATA (ret), random_index_pack_ul, 16);
+  memcpy (GST_BUFFER_DATA (ret) + 16, ber, slen);
+
+  data = GST_BUFFER_DATA (ret) + 16 + slen;
+
+  for (i = 0; i < array->len; i++) {
+    entry = &g_array_index (array, MXFRandomIndexPackEntry, i);
+    GST_WRITE_UINT32_BE (data, entry->body_sid);
+    GST_WRITE_UINT64_BE (data + 4, entry->offset);
+    data += 12;
+  }
+  GST_WRITE_UINT32_BE (data, GST_BUFFER_SIZE (ret));
+
+  return ret;
+}
diff --git a/gst/mxf/mxfwrite.h b/gst/mxf/mxfwrite.h
new file mode 100644
index 00000000..4ebca925
--- /dev/null
+++ b/gst/mxf/mxfwrite.h
@@ -0,0 +1,85 @@
+/* GStreamer
+ * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/* Handling of the basic MXF types */
+
+#ifndef __MXF_WRITE_H__
+#define __MXF_WRITE_H__
+
+#include <string.h>
+#include <gst/gst.h>
+#include <gst/base/gstadapter.h>
+
+#include "mxfmetadata.h"
+#include "mxftypes.h"
+#include "mxfparse.h"
+
+typedef GstFlowReturn (*MXFEssenceElementWriteFunc) (GstBuffer *buffer, GstCaps *caps, gpointer mapping_data, GstAdapter *adapter, GstBuffer **outbuf, gboolean flush);
+
+typedef struct {
+   MXFMetadataFileDescriptor * (*get_descriptor) (GstPadTemplate *tmpl, GstCaps *caps, MXFEssenceElementWriteFunc *handler, gpointer *mapping_data);
+   void (*update_descriptor) (MXFMetadataFileDescriptor *d, GstCaps *caps, gpointer mapping_data, GstBuffer *buf);
+   void (*get_edit_rate) (MXFMetadataFileDescriptor *a, GstCaps *caps, gpointer mapping_data, GstBuffer *buf, MXFMetadataSourcePackage *package, MXFMetadataTimelineTrack *track, MXFFraction *edit_rate);
+   guint32 (*get_track_number_template) (MXFMetadataFileDescriptor *a, GstCaps *caps, gpointer mapping_data);
+   const GstPadTemplate *pad_template;
+   MXFUL data_definition;
+} MXFEssenceElementWriter;
+
+typedef enum {
+  MXF_OP_UNKNOWN = 0,
+  MXF_OP_ATOM,
+  MXF_OP_1a,
+  MXF_OP_1b,
+  MXF_OP_1c,
+  MXF_OP_2a,
+  MXF_OP_2b,
+  MXF_OP_2c,
+  MXF_OP_3a,
+  MXF_OP_3b,
+  MXF_OP_3c,
+} MXFOperationalPattern;
+
+void mxf_essence_element_writer_register (const MXFEssenceElementWriter *writer);
+const GstPadTemplate ** mxf_essence_element_writer_get_pad_templates (void);
+const MXFEssenceElementWriter *mxf_essence_element_writer_find (const GstPadTemplate *templ);
+
+void mxf_ul_set (MXFUL *ul, GHashTable *hashtable);
+void mxf_umid_set (MXFUMID *umid);
+
+void mxf_timestamp_set_now (MXFTimestamp *timestamp);
+void mxf_timestamp_write (const MXFTimestamp *timestamp, guint8 *data);
+
+void mxf_op_set_atom (MXFUL *ul, gboolean single_sourceclip, gboolean single_essence_track);
+void mxf_op_set_generalized (MXFUL *ul, MXFOperationalPattern pattern, gboolean internal_essence, gboolean streamable, gboolean single_track);
+
+guint16 mxf_primer_pack_add_mapping (MXFPrimerPack *primer, guint16 local_tag, const MXFUL *ul);
+
+guint mxf_ber_encode_size (guint size, guint8 ber[9]);
+
+guint8 * mxf_utf8_to_utf16 (const gchar *str, guint16 *size);
+
+void mxf_product_version_write (const MXFProductVersion *version, guint8 *data);
+
+GstBuffer * mxf_partition_pack_to_buffer (const MXFPartitionPack *pack);
+GstBuffer * mxf_primer_pack_to_buffer (const MXFPrimerPack *pack);
+GstBuffer * mxf_fill_new (guint size);
+
+GstBuffer * mxf_random_index_pack_to_buffer (const GArray *array);
+
+#endif /* __MXF_WRITE_H__ */