Added a test application. Added some EXIF tags. Fixed a muxer bug.

Original commit message from CVS:
Added a test application. Added some EXIF tags. Fixed a muxer bug.

11 files changed, 1419 insertions, 105 deletions

diff --git a/ChangeLog b/ChangeLog
index 44305952..846dfd86 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2007-12-13  Edgard Lima  <edgard.lima@indt.org.br>
+
+	* configure.ac:
+	* ext/metadata/Makefile.am:
+	* ext/metadata/gstmetadatamux.c:
+	* ext/metadata/gstmetadataparse.c:
+	* ext/metadata/metadataexif.c:
+	* ext/metadata/metadatatags.c:
+	* ext/metadata/test/Makefile:
+	* ext/metadata/test/MetadataEditorMain.glade:
+	* ext/metadata/test/metadata_editor.c:
+	  Added a test application. Added some EXIF tags. Fixed a muxer bug.
+
 2007-12-13  Sebastian Dröge  <slomo@circular-chaos.org>
 
 	* gst/videoparse/gstvideoparse.c: (gst_video_parse_init),
diff --git a/common b/common
-Subproject fb7ab03319930496e922173d54f6dfccfff6f35
+Subproject ea5f2cfab1a164a5d285fe745343cbe0a476a90
diff --git a/configure.ac b/configure.ac
index f889f922..695a7779 100644
--- a/configure.ac
+++ b/configure.ac
@@ -515,7 +515,7 @@ AG_GST_CHECK_FEATURE(METADATA, [METADATA muxer and demuxer], metadata, [
     ], HAVE_XMP="no")
   if test x$HAVE_EXIF = xyes; then
     METADATA_CFLAGS="-DHAVE_EXIF $EXIF_CFLAGS $METADATA_CFLAGS"
-    METADATA_LIBS="$EXIF_LIBS $METADATA_LIBS"
+    METADATA_LIBS="$EXIF_LIBS $METADATA_LIBS -lm"
     HAVE_METADATA="yes"
   fi
   if test x$HAVE_IPTC = xyes; then
diff --git a/ext/metadata/Makefile.am b/ext/metadata/Makefile.am
index afef850f..753aceff 100644
--- a/ext/metadata/Makefile.am
+++ b/ext/metadata/Makefile.am
@@ -30,6 +30,5 @@ noinst_HEADERS = 	gstmetadataparse.h   \
 			metadataxmp.h        \
 			metadataparseutil.h  \
 			metadatatypes.h      \
-			gstmetadatamux.h     \
-			metadatatags.h
+			gstmetadatamux.h 
 
diff --git a/ext/metadata/gstmetadatamux.c b/ext/metadata/gstmetadatamux.c
index 51fef2fb..953f9cdb 100644
--- a/ext/metadata/gstmetadatamux.c
+++ b/ext/metadata/gstmetadatamux.c
@@ -776,7 +776,6 @@ gst_metadata_update_segment (GstMetadataMux * filter, guint8 ** buf,
   if (*size == 0)
     goto done;
 
-  /* calculate the new position off injected chunks */
   for (i = 0; i < inject_len; ++i) {
     if (inject[i].type == type) {
       inject[i].size = *size;
@@ -1351,6 +1350,7 @@ gst_metadata_mux_strip_push_buffer (GstMetadataMux * filter,
   MetadataChunk *inject = filter->mux_data.inject_chunks.chunk;
   const gsize strip_len = filter->mux_data.strip_chunks.len;
   const gsize inject_len = filter->mux_data.inject_chunks.len;
+  gboolean buffer_reallocated = FALSE;
 
   guint32 size_buf_in = GST_BUFFER_SIZE (*buf);
 
@@ -1422,24 +1422,27 @@ gst_metadata_mux_strip_push_buffer (GstMetadataMux * filter,
 
     guint8 *data;
 
-    if (injected_bytes + prepend_size > striped_bytes) {
-      GstBuffer *new_buf =
-          gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
-          prepend_size - striped_bytes);
+    if (!buffer_reallocated) {
+      buffer_reallocated = TRUE;
+      if (injected_bytes + prepend_size > striped_bytes) {
+        GstBuffer *new_buf =
+            gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
+            prepend_size - striped_bytes);
 
-      memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
-          GST_BUFFER_SIZE (*buf));
+        memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
+            GST_BUFFER_SIZE (*buf));
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
 
-    } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
-      GstBuffer *new_buf = gst_buffer_copy (*buf);
+      } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
+        GstBuffer *new_buf = gst_buffer_copy (*buf);
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
-      GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
-      GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
+        GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
+        GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+      }
     }
 
     data = GST_BUFFER_DATA (*buf);
@@ -1469,24 +1472,27 @@ inject:
     guint8 *data;
     guint32 striped_so_far;
 
-    if (injected_bytes + prepend_size > striped_bytes) {
-      GstBuffer *new_buf =
-          gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
-          prepend_size - striped_bytes);
+    if (!buffer_reallocated) {
+      buffer_reallocated = TRUE;
+      if (injected_bytes + prepend_size > striped_bytes) {
+        GstBuffer *new_buf =
+            gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
+            prepend_size - striped_bytes);
 
-      memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
-          GST_BUFFER_SIZE (*buf));
+        memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
+            GST_BUFFER_SIZE (*buf));
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
 
-    } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
-      GstBuffer *new_buf = gst_buffer_copy (*buf);
+      } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
+        GstBuffer *new_buf = gst_buffer_copy (*buf);
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
-      GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
-      GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
+        GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
+        GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+      }
     }
 
     data = GST_BUFFER_DATA (*buf);
@@ -1515,7 +1521,7 @@ inject:
               size_buf_in - buf_off);
           memcpy (data + buf_off, inject[i].data, inject[i].size);
           injected_bytes += inject[i].size;
-          size_buf_in += injected_bytes;
+          size_buf_in += inject[i].size;
         } else {
           /* segment is after size (segments are sorted) */
           break;
diff --git a/ext/metadata/gstmetadataparse.c b/ext/metadata/gstmetadataparse.c
index 3dd07cb2..a8ded250 100644
--- a/ext/metadata/gstmetadataparse.c
+++ b/ext/metadata/gstmetadataparse.c
@@ -1312,6 +1312,7 @@ gst_metadata_parse_strip_push_buffer (GstMetadataParse * filter,
   MetadataChunk *inject = filter->parse_data.inject_chunks.chunk;
   const gsize strip_len = filter->parse_data.strip_chunks.len;
   const gsize inject_len = filter->parse_data.inject_chunks.len;
+  gboolean buffer_reallocated = FALSE;
 
   guint32 size_buf_in = GST_BUFFER_SIZE (*buf);
 
@@ -1383,24 +1384,27 @@ gst_metadata_parse_strip_push_buffer (GstMetadataParse * filter,
 
     guint8 *data;
 
-    if (injected_bytes + prepend_size > striped_bytes) {
-      GstBuffer *new_buf =
-          gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
-          prepend_size - striped_bytes);
+    if (!buffer_reallocated) {
+      buffer_reallocated = TRUE;
+      if (injected_bytes + prepend_size > striped_bytes) {
+        GstBuffer *new_buf =
+            gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
+            prepend_size - striped_bytes);
 
-      memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
-          GST_BUFFER_SIZE (*buf));
+        memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
+            GST_BUFFER_SIZE (*buf));
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
 
-    } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
-      GstBuffer *new_buf = gst_buffer_copy (*buf);
+      } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
+        GstBuffer *new_buf = gst_buffer_copy (*buf);
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
-      GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
-      GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
+        GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
+        GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+      }
     }
 
     data = GST_BUFFER_DATA (*buf);
@@ -1430,24 +1434,27 @@ inject:
     guint8 *data;
     guint32 striped_so_far;
 
-    if (injected_bytes + prepend_size > striped_bytes) {
-      GstBuffer *new_buf =
-          gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
-          prepend_size - striped_bytes);
+    if (!buffer_reallocated) {
+      buffer_reallocated = TRUE;
+      if (injected_bytes + prepend_size > striped_bytes) {
+        GstBuffer *new_buf =
+            gst_buffer_new_and_alloc (GST_BUFFER_SIZE (*buf) + injected_bytes +
+            prepend_size - striped_bytes);
 
-      memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
-          GST_BUFFER_SIZE (*buf));
+        memcpy (GST_BUFFER_DATA (new_buf), GST_BUFFER_DATA (*buf),
+            GST_BUFFER_SIZE (*buf));
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
 
-    } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
-      GstBuffer *new_buf = gst_buffer_copy (*buf);
+      } else if (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_READONLY)) {
+        GstBuffer *new_buf = gst_buffer_copy (*buf);
 
-      gst_buffer_unref (*buf);
-      *buf = new_buf;
-      GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
-      GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+        gst_buffer_unref (*buf);
+        *buf = new_buf;
+        GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
+        GST_BUFFER_SIZE (*buf) += injected_bytes + prepend_size - striped_bytes;
+      }
     }
 
     data = GST_BUFFER_DATA (*buf);
@@ -1476,7 +1483,7 @@ inject:
               size_buf_in - buf_off);
           memcpy (data + buf_off, inject[i].data, inject[i].size);
           injected_bytes += inject[i].size;
-          size_buf_in += injected_bytes;
+          size_buf_in += inject[i].size;
         } else {
           /* segment is after size (segments are sorted) */
           break;
diff --git a/ext/metadata/metadataexif.c b/ext/metadata/metadataexif.c
index c45a93e4..65ade6ea 100644
--- a/ext/metadata/metadataexif.c
+++ b/ext/metadata/metadataexif.c
@@ -75,6 +75,8 @@ metadatamux_exif_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
 
 #include <libexif/exif-data.h>
 #include <stdlib.h>
+#include <string.h>
+#include <math.h>
 
 typedef struct _tag_MEUserData
 {
@@ -95,37 +97,55 @@ exif_data_foreach_content_func (ExifContent * content, void *callback_data);
 
 static void exif_content_foreach_entry_func (ExifEntry * entry, void *);
 
-const gchar *
+/* *INDENT-OFF* */
+static MapIntStr mappedTags[] = {
+  {EXIF_TAG_MAKE,               /*EXIF_FORMAT_ASCII,*/     GST_TAG_DEVICE_MAKE,              G_TYPE_STRING},
+  {EXIF_TAG_MODEL,              /*EXIF_FORMAT_ASCII,*/     GST_TAG_DEVICE_MODEL,             G_TYPE_STRING},
+  {EXIF_TAG_SOFTWARE,           /*EXIF_FORMAT_ASCII,*/     GST_TAG_CREATOR_TOOL,             G_TYPE_STRING},
+  {EXIF_TAG_X_RESOLUTION,       /*EXIF_FORMAT_RATIONAL,*/  GST_TAG_IMAGE_XRESOLUTION,        G_TYPE_FLOAT},   /* inches */
+  {EXIF_TAG_Y_RESOLUTION,       /*EXIF_FORMAT_RATIONAL,*/  GST_TAG_IMAGE_YRESOLUTION,        G_TYPE_FLOAT},   /* inches */
+  {EXIF_TAG_EXPOSURE_TIME,      /*EXIF_FORMAT_RATIONAL,*/  GST_TAG_CAPTURE_EXPOSURE_TIME,    G_TYPE_FLOAT},
+  {EXIF_TAG_FNUMBER,            /*EXIF_FORMAT_RATIONAL,*/  GST_TAG_CAPTURE_FNUMBER,          G_TYPE_FLOAT},
+  {EXIF_TAG_EXPOSURE_PROGRAM,   /*EXIF_FORMAT_SHORT,*/     GST_TAG_CAPTURE_EXPOSURE_PROGRAM, G_TYPE_UINT},
+  {EXIF_TAG_BRIGHTNESS_VALUE,   /*EXIF_FORMAT_SRATIONAL,*/ GST_TAG_CAPTURE_BRIGHTNESS,       G_TYPE_FLOAT},
+  {EXIF_TAG_WHITE_BALANCE,      /*EXIF_FORMAT_SHORT,*/     GST_TAG_CAPTURE_WHITE_BALANCE,    G_TYPE_UINT},
+  {EXIF_TAG_DIGITAL_ZOOM_RATIO, /*EXIF_FORMAT_RATIONAL,*/  GST_TAG_CAPTURE_DIGITAL_ZOOM,     G_TYPE_FLOAT},
+  {EXIF_TAG_GAIN_CONTROL,       /*EXIF_FORMAT_SHORT,*/     GST_TAG_CAPTURE_GAIN,             G_TYPE_UINT},
+  {EXIF_TAG_CONTRAST,           /*EXIF_FORMAT_SHORT,*/     GST_TAG_CAPTURE_CONTRAST,         G_TYPE_INT},
+  {EXIF_TAG_SATURATION,         /*EXIF_FORMAT_SHORT,*/     GST_TAG_CAPTURE_SATURATION,       G_TYPE_INT},
+  {0, NULL, G_TYPE_NONE}
+};
+/* *INDENT-ON* */
+
+static const gchar *
 metadataparse_exif_get_tag_from_exif (ExifTag exif, GType * type)
 {
-  /* FIXEME: sorted with binary search */
-  static MapIntStr array[] = {
-    {EXIF_TAG_MAKE, GST_TAG_DEVICE_MAKE, G_TYPE_STRING},
-    {EXIF_TAG_MODEL, GST_TAG_DEVICE_MODEL, G_TYPE_STRING},
-    {EXIF_TAG_SOFTWARE, GST_TAG_CREATOR_TOOL, G_TYPE_STRING},
-    {EXIF_TAG_X_RESOLUTION, GST_TAG_IMAGE_XRESOLUTION, G_TYPE_FLOAT},   /* asure inches */
-    {EXIF_TAG_Y_RESOLUTION, GST_TAG_IMAGE_YRESOLUTION, G_TYPE_FLOAT},   /* asure inches */
-    {EXIF_TAG_EXPOSURE_TIME, GST_TAG_CAPTURE_EXPOSURE_TIME, G_TYPE_FLOAT},
-    {EXIF_TAG_FNUMBER, GST_TAG_CAPTURE_FNUMBER, G_TYPE_FLOAT},
-    {EXIF_TAG_EXPOSURE_PROGRAM, GST_TAG_CAPTURE_EXPOSURE_PROGRAM, G_TYPE_UINT},
-    {EXIF_TAG_BRIGHTNESS_VALUE, GST_TAG_CAPTURE_BRIGHTNESS, G_TYPE_FLOAT},
-    {EXIF_TAG_WHITE_BALANCE, GST_TAG_CAPTURE_WHITE_BALANCE, G_TYPE_UINT},
-    {EXIF_TAG_DIGITAL_ZOOM_RATIO, GST_TAG_CAPTURE_DIGITAL_ZOOM, G_TYPE_FLOAT},
-    {EXIF_TAG_GAIN_CONTROL, GST_TAG_CAPTURE_GAIN, G_TYPE_UINT},
-    {EXIF_TAG_CONTRAST, GST_TAG_CAPTURE_CONTRAST, G_TYPE_UINT},
-    {EXIF_TAG_SATURATION, GST_TAG_CAPTURE_SATURATION, G_TYPE_UINT},
-    {0, NULL, G_TYPE_NONE, G_TYPE_UINT}
-  };
   int i = 0;
 
-  while (array[i].exif) {
-    if (exif == array[i].exif)
+  while (mappedTags[i].exif) {
+    if (exif == mappedTags[i].exif)
       break;
     ++i;
   }
 
-  *type = array[i].type;
-  return array[i].str;
+  *type = mappedTags[i].type;
+  return mappedTags[i].str;
+
+}
+
+static ExifTag
+metadataparse_exif_get_exif_from_tag (const gchar * tag, GType * type)
+{
+  int i = 0;
+
+  while (mappedTags[i].exif) {
+    if (0 == strcmp (mappedTags[i].str, tag))
+      break;
+    ++i;
+  }
+
+  *type = mappedTags[i].type;
+  return mappedTags[i].exif;
 
 }
 
@@ -180,6 +200,31 @@ exif_data_foreach_content_func (ExifContent * content, void *user_data)
       user_data);
 }
 
+#if 0
+static gboolean
+exif_fast_mdc (glong n, glong d, gulong * m)
+{
+  gboolean ret = FALSE;
+
+  static const int a[] =
+      { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 39, 41, 43, 47, 49, 53, 0 };
+  int i = 0;
+
+  *m = 1;
+
+  while (a[i] <= n && a[i] <= d) {
+    while ((n % a[i] == 0) && (d % a[i]) == 0) {
+      *m *= a[i];
+      ret = TRUE;
+    }
+    ++i;
+  }
+
+  return ret;
+
+}
+#endif
+
 static void
 exif_content_foreach_entry_func (ExifEntry * entry, void *user_data)
 {
@@ -223,65 +268,83 @@ exif_content_foreach_entry_func (ExifEntry * entry, void *user_data)
       case G_TYPE_FLOAT:
       {
         gfloat f_value;
-        ExifRational v_rat;
 
         switch (entry->format) {
+          case EXIF_FORMAT_SRATIONAL:
+          {
+            ExifSRational v_srat;
+
+            v_srat = exif_get_srational (entry->data, byte_order);
+            if (v_srat.denominator == 0)
+              f_value = 0.0f;
+            else
+              f_value = (float) v_srat.numerator / (float) v_srat.denominator;
+            if (v_srat.numerator == 0xFFFFFFFF) {
+              if (entry->tag == EXIF_TAG_BRIGHTNESS_VALUE) {
+                f_value = 100.0f;
+              }
+            }
+          }
+            break;
           case EXIF_FORMAT_RATIONAL:
+          {
+            ExifRational v_rat;
+
             v_rat = exif_get_rational (entry->data, byte_order);
-            if (v_rat.numerator == 0)
+            if (v_rat.denominator == 0)
               f_value = 0.0f;
             else
               f_value = (float) v_rat.numerator / (float) v_rat.denominator;
-            if (v_rat.numerator == 0xFFFFFFFF) {
-              if (entry->tag == GST_TAG_CAPTURE_BRIGHTNESS) {
-                f_value = 100.0f;
+            if (meudata->resolution_unit == 3) {
+              /* converts from cm to inches */
+              if (entry->tag == EXIF_TAG_X_RESOLUTION
+                  || entry->tag == EXIF_TAG_Y_RESOLUTION) {
+                f_value *= 0.4f;
               }
             }
+          }
             break;
           default:
             GST_ERROR ("Unexpected Tag Type");
             goto done;
             break;
         }
-        if (meudata->resolution_unit == 3) {
-          /* converts from cm to inches */
-          if (entry->tag == EXIF_TAG_X_RESOLUTION
-              || entry->tag == EXIF_TAG_Y_RESOLUTION) {
-            f_value *= 0.4f;
-          }
-        }
         gst_tag_list_add (meudata->taglist, meudata->mode, tag, f_value, NULL);
       }
+        break;
+      case G_TYPE_INT:
+        /* fall through */
       case G_TYPE_UINT:
       {
-        ExifShort v_short;
+        gint value;
 
         switch (entry->format) {
           case EXIF_FORMAT_SHORT:
-            v_short = exif_get_short (entry->data, byte_order);
+            value = exif_get_short (entry->data, byte_order);
             break;
           default:
-            GST_ERROR ("Unexpected Tag Type");
+            GST_ERROR ("Unexpected Exif Tag Type (%s - %s)",
+                tag, exif_format_get_name (entry->format));
             goto done;
             break;
         }
         if (entry->tag == EXIF_TAG_CONTRAST ||
             entry->tag == EXIF_TAG_SATURATION) {
-          switch (v_short) {
+          switch (value) {
             case 0:
               break;
             case 1:
-              v_short = -67;
+              value = -67;      /* -100-34 /2 */
               break;
             case 2:
-              v_short = 66;
+              value = 67;       /* 100+34 /2 */
               break;
             default:
               GST_ERROR ("Unexpected value");
               break;
           }
         }
-        gst_tag_list_add (meudata->taglist, meudata->mode, tag, v_short, NULL);
+        gst_tag_list_add (meudata->taglist, meudata->mode, tag, value, NULL);
       }
         break;
       default:
@@ -313,6 +376,188 @@ done:
  *
  */
 
+static ExifRational
+float_to_rational (gfloat f)
+{
+  ExifRational r;
+  int i = 6;                    /* precision */
+
+  r.denominator = 1;
+
+  while (i--) {
+    if (f == floorf (f)) {
+      break;
+    }
+    f *= 10.0f;
+    r.denominator *= 10;
+  }
+
+  r.numerator = f;
+
+  if (!(r.numerator & 0x1 || r.denominator & 0x1)) {
+    /* divide both by 2 */
+    r.numerator >>= 1;
+    r.denominator >>= 1;
+  }
+  if (r.numerator % 5 == 0 && r.denominator % 5 == 0) {
+    r.numerator /= 5;
+    r.denominator /= 5;
+  }
+
+  return r;
+
+}
+
+static ExifSRational
+float_to_srational (gfloat f)
+{
+  ExifSRational sr;
+  int i = 6;                    /* precision */
+
+  sr.denominator = 1;
+
+  while (i--) {
+    if (f == floorf (f)) {
+      break;
+    }
+    f *= 10.0f;
+    sr.denominator *= 10;
+  }
+
+  sr.numerator = f;
+
+  if (!(sr.numerator & 0x1 || sr.denominator & 0x1)) {
+    /* divide both by 2 */
+    sr.numerator >>= 1;
+    sr.denominator >>= 1;
+  }
+  if (sr.numerator % 5 == 0 && sr.denominator % 5 == 0) {
+    sr.numerator /= 5;
+    sr.denominator /= 5;
+  }
+
+  return sr;
+
+}
+
+static void
+metadataexif_for_each_tag_in_list (const GstTagList * list, const gchar * tag,
+    gpointer user_data)
+{
+  ExifData *ed = (ExifData *) user_data;
+  ExifTag exif_tag;
+  GType type;
+  ExifEntry *entry = NULL;
+  const ExifByteOrder byte_order = exif_data_get_byte_order (ed);
+
+  exif_tag = metadataparse_exif_get_exif_from_tag (tag, &type);
+
+  if (!exif_tag)
+    goto done;
+
+  entry = exif_data_get_entry (ed, exif_tag);
+
+  if (entry)
+    exif_entry_ref (entry);
+  else {
+    entry = exif_entry_new ();
+    exif_content_add_entry (ed->ifd[EXIF_IFD_0], entry);
+    exif_entry_initialize (entry, exif_tag);
+  }
+
+  switch (type) {
+    case G_TYPE_STRING:
+    {
+      gchar *value = NULL;
+
+      if (gst_tag_list_get_string (list, tag, &value)) {
+        entry->components = strlen (value) + 1;
+        entry->size = exif_format_get_size (entry->format) * entry->components;
+        entry->data = value;
+      }
+    }
+      break;
+    case G_TYPE_FLOAT:
+    {
+      gfloat value;
+
+      gst_tag_list_get_float (list, tag, &value);
+
+      switch (entry->format) {
+        case EXIF_FORMAT_SRATIONAL:
+        {
+          ExifSRational sr;
+
+          sr = float_to_srational (value);
+          if (entry->tag == EXIF_TAG_BRIGHTNESS_VALUE) {
+            if (value == 100.0f) {
+              sr.numerator = 0xFFFFFFFF;
+              sr.denominator = 1;
+            }
+          }
+
+          exif_set_srational (entry->data, byte_order, sr);
+        }
+          break;
+        case EXIF_FORMAT_RATIONAL:
+        {
+          ExifRational r;
+
+          r = float_to_rational (value);
+          exif_set_rational (entry->data, byte_order, r);
+          if (entry->tag == EXIF_TAG_X_RESOLUTION ||
+              entry->tag == EXIF_TAG_Y_RESOLUTION) {
+            ExifEntry *unit_entry = NULL;
+
+            if ((unit_entry =
+                    exif_data_get_entry (ed, EXIF_TAG_RESOLUTION_UNIT))) {
+              ExifShort vsh = exif_get_short (unit_entry->data, byte_order);
+
+              if (vsh != 2)     /* inches */
+                exif_set_short (unit_entry->data, byte_order, 2);
+            }
+          }
+        }
+          break;
+        default:
+          break;
+      }
+    }
+      break;
+    case G_TYPE_UINT:
+    case G_TYPE_INT:
+    {
+      gint value;
+      ExifShort v_short;
+
+      if (G_TYPE_UINT == type) {
+        gst_tag_list_get_uint (list, tag, &value);
+      } else {
+        gst_tag_list_get_int (list, tag, &value);
+      }
+      if (entry->tag == EXIF_TAG_CONTRAST || entry->tag == EXIF_TAG_SATURATION) {
+        if (value < -33)
+          value = 1;            /* low */
+        else if (value < 34)
+          value = 0;            /* normal */
+        else
+          value = 2;            /* high */
+      }
+      v_short = value;
+      exif_set_short (entry->data, byte_order, v_short);
+    }
+      break;
+    default:
+      break;
+  }
+
+done:
+
+  if (entry)
+    exif_entry_unref (entry);
+
+}
+
 void
 metadatamux_exif_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
     const GstTagList * taglist)
@@ -344,7 +589,7 @@ metadatamux_exif_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
     exif_data_fix (ed);
   }
 
-  /* FIXME: consider individual tags */
+  gst_tag_list_foreach (taglist, metadataexif_for_each_tag_in_list, ed);
 
   exif_data_save_data (ed, buf, size);
 
diff --git a/ext/metadata/metadatatags.c b/ext/metadata/metadatatags.c
index 45988922..00f3956b 100644
--- a/ext/metadata/metadatatags.c
+++ b/ext/metadata/metadatatags.c
@@ -172,12 +172,18 @@ metadata_tags_register (void)
       GST_TAG_CAPTURE_GAIN, "", NULL);
   /**
      from -100 to 100
+     [-100, -34] - soft
+     [-33, 33] - normal
+     [34, 100] - hard
      *** exif is just 0, 1, 2 (normal, soft and hard)
   */
   gst_tag_register (GST_TAG_CAPTURE_CONTRAST, GST_TAG_FLAG_META, G_TYPE_INT,
       GST_TAG_CAPTURE_CONTRAST, "", NULL);
   /**
      from -100 to 100
+     [-100, -34] - low
+     [-33, 33] - normal
+     [34, 100] - high
      *** exif is just 0, 1, 2 (normal, low and high)
   */
   gst_tag_register (GST_TAG_CAPTURE_SATURATION, GST_TAG_FLAG_META, G_TYPE_INT,
diff --git a/ext/metadata/test/Makefile b/ext/metadata/test/Makefile
new file mode 100644
index 00000000..dfcd3f73
--- /dev/null
+++ b/ext/metadata/test/Makefile
@@ -0,0 +1,16 @@
+
+CC=gcc
+CFLAGS=-c -Wall -g3 -O0 `pkg-config --cflags gstreamer-0.10 libglade-2.0 gtk+-2.0`
+CLIBS=-lgstinterfaces-0.10 -Wl -export-dynamic `pkg-config --libs gstreamer-0.10 libglade-2.0 gtk+-2.0`
+
+all: metadata_editor
+
+metadata_editor: metadata_editor.o
+	$(CC) $(CLIBS) metadata_editor.o -o metadata_editor
+
+metadata_editor.o: metadata_editor.c
+	$(CC) $(CFLAGS) metadata_editor.c
+
+clean:
+	rm -rf *.o metadata_editor
+
diff --git a/ext/metadata/test/MetadataEditorMain.glade b/ext/metadata/test/MetadataEditorMain.glade
new file mode 100644
index 00000000..ecd09be5
--- /dev/null
+++ b/ext/metadata/test/MetadataEditorMain.glade
@@ -0,0 +1,141 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE glade-interface SYSTEM "glade-2.0.dtd">
+<!--Generated with glade3 3.2.0 on Wed Dec 12 14:07:03 2007 by edlima@feisty-laptop-->
+<glade-interface>
+  <widget class="GtkWindow" id="windowMain">
+    <property name="width_request">800</property>
+    <property name="height_request">600</property>
+    <property name="events">GDK_EXPOSURE_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+    <property name="title" translatable="yes">Metadata Editor</property>
+    <signal name="configure_event" handler="on_windowMain_configure_event"/>
+    <signal name="delete_event" handler="on_windowMain_delete_event"/>
+    <child>
+      <widget class="GtkVPaned" id="vpanedMain">
+        <property name="visible">True</property>
+        <property name="can_focus">True</property>
+        <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+        <child>
+          <widget class="GtkDrawingArea" id="drawingMain">
+            <property name="width_request">200</property>
+            <property name="height_request">100</property>
+            <property name="visible">True</property>
+            <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+            <signal name="expose_event" handler="on_drawingMain_expose_event"/>
+          </widget>
+          <packing>
+            <property name="resize">False</property>
+            <property name="shrink">False</property>
+          </packing>
+        </child>
+        <child>
+          <widget class="GtkVBox" id="vboxMain">
+            <property name="visible">True</property>
+            <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+            <child>
+              <widget class="GtkScrolledWindow" id="scrolledwindow">
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                <property name="hscrollbar_policy">GTK_POLICY_AUTOMATIC</property>
+                <property name="vscrollbar_policy">GTK_POLICY_AUTOMATIC</property>
+                <child>
+                  <widget class="GtkTreeView" id="treeMain">
+                    <property name="visible">True</property>
+                    <property name="can_focus">True</property>
+                    <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                    <property name="headers_clickable">True</property>
+                    <property name="rules_hint">True</property>
+                    <property name="enable_search">False</property>
+                    <property name="hover_expand">True</property>
+                  </widget>
+                </child>
+              </widget>
+            </child>
+            <child>
+              <widget class="GtkVBox" id="vboxEditBnt">
+                <property name="visible">True</property>
+                <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                <child>
+                  <widget class="GtkHBox" id="hboxEdit">
+                    <property name="visible">True</property>
+                    <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                    <child>
+                      <widget class="GtkEntry" id="entryTag">
+                        <property name="width_request">300</property>
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                      </widget>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">False</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <widget class="GtkEntry" id="entryValue">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                      </widget>
+                      <packing>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                  </widget>
+                </child>
+                <child>
+                  <widget class="GtkHButtonBox" id="hbuttonboxBnt">
+                    <property name="visible">True</property>
+                    <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                    <property name="homogeneous">True</property>
+                    <property name="layout_style">GTK_BUTTONBOX_SPREAD</property>
+                    <child>
+                      <widget class="GtkButton" id="buttonInsert">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                        <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                        <property name="label" translatable="yes">Insert</property>
+                        <signal name="clicked" handler="on_buttonInsert_clicked"/>
+                      </widget>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">False</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <widget class="GtkButton" id="buttonSaveFile">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                        <property name="events">GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK</property>
+                        <property name="label" translatable="yes">Save File</property>
+                        <signal name="clicked" handler="on_buttonSaveFile_clicked"/>
+                      </widget>
+                      <packing>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                  </widget>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">False</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+              </widget>
+              <packing>
+                <property name="expand">False</property>
+                <property name="fill">False</property>
+                <property name="position">1</property>
+              </packing>
+            </child>
+          </widget>
+          <packing>
+            <property name="shrink">False</property>
+          </packing>
+        </child>
+      </widget>
+    </child>
+  </widget>
+</glade-interface>
diff --git a/ext/metadata/test/metadata_editor.c b/ext/metadata/test/metadata_editor.c
new file mode 100644
index 00000000..4228b227
--- /dev/null
+++ b/ext/metadata/test/metadata_editor.c
@@ -0,0 +1,881 @@
+/*
+ * GStreamer
+ * Copyright 2007 Edgard Lima <edgard.lima@indt.org.br>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <gst/gst.h>
+#include <glade/glade-xml.h>
+#include <gtk/gtk.h>
+#include <gst/interfaces/xoverlay.h>
+#include <gdk/gdkx.h>
+
+/*
+ * Global constants
+ */
+
+enum
+{
+  COL_TAG = 0,
+  COL_VALUE,
+  NUM_COLS
+};
+
+#define ENC_ERROR (-1)
+#define ENC_DONE (0)
+#define ENC_UNKNOWN (1)
+
+
+/*
+ * functions prototypes
+ */
+
+/* gstreamer related functions */
+
+static void me_gst_cleanup_elements ();
+static int
+me_gst_setup_view_pipeline (const gchar * filename, GdkWindow * window);
+static int
+me_gst_setup_encode_pipeline (const gchar * src_file, const gchar * dest_file,
+    gint * encode_status);
+
+/* ui related functions */
+
+static void ui_refresh ();
+
+/*
+ * Global Vars 
+ */
+
+GstElement *gst_source = NULL;
+GstElement *gst_metadata_demux = NULL;
+GstElement *gst_metadata_mux = NULL;
+GstElement *gst_image_dec = NULL;
+GstElement *gst_video_scale = NULL;
+GstElement *gst_video_convert = NULL;
+GstElement *gst_video_sink = NULL;
+GstElement *gst_file_sink = NULL;
+GstElement *gst_pipeline = NULL;
+
+GstTagList *tag_list = NULL;
+
+GladeXML *ui_glade_xml = NULL;
+GtkWidget *ui_main_window = NULL;
+GtkWidget *ui_drawing = NULL;
+GtkWidget *ui_tree = NULL;
+
+GtkEntry *ui_entry_insert_tag = NULL;
+GtkEntry *ui_entry_insert_value = NULL;
+
+GString *filename = NULL;
+
+/*
+ * Helper functions
+ */
+
+static void
+insert_tag_on_tree (const GstTagList * list, const gchar * tag,
+    gpointer user_data)
+{
+  gchar *str = NULL;
+  GtkTreeView *tree_view = NULL;
+  GtkTreeStore *tree_store = NULL;
+  GtkTreeIter iter;
+
+  tree_view = GTK_TREE_VIEW (user_data);
+
+  if (gst_tag_get_type (tag) == G_TYPE_STRING) {
+    if (!gst_tag_list_get_string_index (list, tag, 0, &str))
+      g_assert_not_reached ();
+  } else {
+    str = g_strdup_value_contents (gst_tag_list_get_value_index (list, tag, 0));
+  }
+
+  tree_store = GTK_TREE_STORE (gtk_tree_view_get_model (tree_view));
+  gtk_tree_store_append (tree_store, &iter, NULL);
+  gtk_tree_store_set (tree_store, &iter, COL_TAG, tag, COL_VALUE, str, -1);
+
+  if (str)
+    g_free (str);
+
+}
+
+static gboolean
+change_tag_list (GstTagList ** list, const gchar * tag, const gchar * value)
+{
+  GType type;
+  gboolean ret = FALSE;
+
+  if (list == NULL || tag == NULL || value == NULL)
+    goto done;
+
+  if (!gst_tag_exists (tag)) {
+    fprintf (stderr, "%s is not a GStreamer registered tag\n", tag);
+    goto done;
+  }
+
+  if (*list == NULL)
+    *list = gst_tag_list_new ();
+
+  type = gst_tag_get_type (tag);
+
+  switch (type) {
+    case G_TYPE_STRING:
+      gst_tag_list_add (*list, GST_TAG_MERGE_REPLACE, tag, value, NULL);
+      ret = TRUE;
+      break;
+    case G_TYPE_FLOAT:
+    {
+      gfloat fv = (gfloat) g_strtod (value, NULL);
+
+      gst_tag_list_add (*list, GST_TAG_MERGE_REPLACE, tag, fv, NULL);
+      ret = TRUE;
+    }
+      break;
+    case G_TYPE_INT:
+      /* fall through */
+    case G_TYPE_UINT:
+    {
+      gint iv = atoi (value);
+
+      gst_tag_list_add (*list, GST_TAG_MERGE_REPLACE, tag, iv, NULL);
+      ret = TRUE;
+    }
+      break;
+    default:
+      fprintf (stderr, "This app still doesn't handle type (%s)(%ld)\n",
+          g_type_name (type), type);
+      break;
+  }
+
+done:
+
+  return ret;
+
+}
+
+
+/*
+ * UI handling functions (mapped by glade)
+ */
+
+gboolean
+on_windowMain_configure_event (GtkWidget * widget, GdkEventConfigure * event,
+    gpointer user_data)
+{
+  GstXOverlay *xoverlay;
+
+  if (gst_video_sink) {
+
+    xoverlay = GST_X_OVERLAY (gst_video_sink);
+
+    if (xoverlay != NULL && GST_IS_X_OVERLAY (xoverlay)) {
+      gst_x_overlay_expose (xoverlay);
+    }
+
+  }
+
+  return FALSE;
+}
+
+gboolean
+on_drawingMain_expose_event (GtkWidget * widget, GdkEventExpose * event,
+    gpointer data)
+{
+  if (gst_video_sink) {
+    gst_x_overlay_set_xwindow_id (GST_X_OVERLAY (gst_video_sink),
+        GDK_WINDOW_XWINDOW (widget->window));
+  }
+  return FALSE;
+}
+
+void
+on_windowMain_delete_event (GtkWidget * widget, GdkEvent * event,
+    gpointer user_data)
+{
+  gst_element_set_state (gst_pipeline, GST_STATE_NULL);
+  gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+  gtk_main_quit ();
+}
+
+void
+on_buttonInsert_clicked (GtkButton * button, gpointer user_data)
+{
+  GtkTreeStore *store = NULL;
+  GtkTreeIter iter;
+  const gchar *tag = gtk_entry_get_text (ui_entry_insert_tag);
+  const gchar *value = gtk_entry_get_text (ui_entry_insert_value);
+
+  if (tag && value && tag[0] != '\0') {
+
+    /* insert just new tags (the ones already in list should be modified) */
+    if (gst_tag_list_get_tag_size (tag_list, tag)) {
+      fprintf (stderr, "%s tag is already in the list try to modify it\n", tag);
+    } else {
+      if (change_tag_list (&tag_list, tag, value)) {
+        /* just add to ui_tree if it has been added to tag_list */
+        store =
+            GTK_TREE_STORE (gtk_tree_view_get_model (GTK_TREE_VIEW (ui_tree)));
+        gtk_tree_store_append (store, &iter, NULL);
+        gtk_tree_store_set (store, &iter, COL_TAG, tag, COL_VALUE, value, -1);
+      }
+    }
+
+  }
+
+  return;
+
+}
+
+void
+on_buttonSaveFile_clicked (GtkButton * button, gpointer user_data)
+{
+
+  GString *src_file = NULL;
+  gint enc_status = ENC_UNKNOWN;
+
+  gst_element_set_state (gst_pipeline, GST_STATE_NULL);
+  gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+
+  src_file = g_string_new (filename->str);
+
+  g_string_prepend (filename, "_new_");
+  remove (filename->str);
+
+  ui_refresh ();
+
+  if (me_gst_setup_encode_pipeline (src_file->str, filename->str, &enc_status)) {
+    goto done;
+  }
+
+  if (tag_list && gst_metadata_mux) {
+    GstTagSetter *setter = GST_TAG_SETTER (gst_metadata_mux);
+
+    if (setter) {
+      gst_element_set_state (gst_pipeline, GST_STATE_READY);
+      gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+
+      gst_tag_setter_merge_tags (setter, tag_list, GST_TAG_MERGE_REPLACE);
+
+    }
+  }
+
+  gst_element_set_state (gst_pipeline, GST_STATE_PLAYING);
+  gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+
+  /* wait until finished */
+  gtk_main ();
+
+  gst_element_set_state (gst_pipeline, GST_STATE_NULL);
+  gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+
+  if (enc_status == ENC_DONE) {
+
+    /* view new file */
+    if (tag_list) {
+      gst_tag_list_free (tag_list);
+      tag_list = NULL;
+    }
+
+    me_gst_setup_view_pipeline (filename->str, ui_drawing->window);
+
+    gst_element_set_state (gst_pipeline, GST_STATE_PLAYING);
+    gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+
+  }
+
+done:
+
+  if (src_file)
+    g_string_free (src_file, TRUE);
+
+}
+
+/*
+ * UI handling functions
+ */
+
+void
+on_cell_edited (GtkCellRendererText * renderer, gchar * str_path,
+    gchar * new_text, gpointer user_data)
+{
+  GtkTreePath *path = NULL;
+  GtkTreeIter iter;
+  GtkTreeModel *model = NULL;
+  const guint32 col_index = (guint32) user_data;
+  const gchar *tag = gtk_entry_get_text (ui_entry_insert_tag);
+
+  path = gtk_tree_path_new_from_string (str_path);
+  model = gtk_tree_view_get_model (GTK_TREE_VIEW (ui_tree));
+
+  if (change_tag_list (&tag_list, tag, new_text)) {
+
+    if (gtk_tree_model_get_iter (model, &iter, path)) {
+      gtk_tree_store_set (GTK_TREE_STORE (model), &iter, col_index, new_text,
+          -1);
+      gtk_entry_set_text (ui_entry_insert_value, new_text);
+    }
+
+  }
+
+  if (path)
+    gtk_tree_path_free (path);
+
+}
+
+static void
+on_tree_selection_changed (GtkTreeSelection * selection, gpointer data)
+{
+  GtkTreeIter iter;
+  GtkTreeModel *model;
+
+  if (gtk_tree_selection_get_selected (selection, &model, &iter)) {
+    gchar *tag;
+    gchar *value;
+
+    gtk_tree_model_get (model, &iter, COL_TAG, &tag, -1);
+    gtk_tree_model_get (model, &iter, COL_VALUE, &value, -1);
+
+    gtk_entry_set_text (ui_entry_insert_tag, tag);
+    gtk_entry_set_text (ui_entry_insert_value, value);
+
+    g_free (value);
+    g_free (tag);
+
+  }
+
+}
+
+/*
+ * UI helper functions
+ */
+
+static int
+ui_add_columns (GtkTreeView * tree_view, const gchar * title, gint col_index,
+    gboolean editable)
+{
+  GtkCellRenderer *renderer;
+  GtkTreeViewColumn *tree_col;
+  int ret = 0;
+
+  renderer = gtk_cell_renderer_text_new ();
+
+  if (editable) {
+    g_object_set (renderer, "editable", TRUE, NULL);
+    g_signal_connect (G_OBJECT (renderer), "edited",
+        G_CALLBACK (on_cell_edited), (gpointer) col_index);
+  }
+
+  if ((tree_col = gtk_tree_view_column_new_with_attributes (title, renderer,
+              "text", col_index, NULL))) {
+    gtk_tree_view_append_column (tree_view, tree_col);
+  } else {
+    fprintf (stderr, "UI: could not create column %s\n", title);
+    ret = -201;
+    goto done;
+  }
+
+done:
+
+  return ret;
+
+}
+
+
+static int
+ui_setup_tree_view (GtkTreeView * tree_view)
+{
+  int ret = 0;
+  GtkTreeStore *tree_store = NULL;
+  GtkTreeSelection *select;
+
+  if ((ret = ui_add_columns (tree_view, "tag", COL_TAG, FALSE)))
+    goto done;
+
+  if ((ret = ui_add_columns (tree_view, "value", COL_VALUE, TRUE)))
+    goto done;
+
+  tree_store = gtk_tree_store_new (NUM_COLS, G_TYPE_STRING, G_TYPE_STRING);
+
+  gtk_tree_view_set_model (tree_view, GTK_TREE_MODEL (tree_store));
+
+  select = gtk_tree_view_get_selection (tree_view);
+  gtk_tree_selection_set_mode (select, GTK_SELECTION_SINGLE);
+  g_signal_connect (G_OBJECT (select), "changed",
+      G_CALLBACK (on_tree_selection_changed), NULL);
+
+done:
+
+  if (tree_store)
+    g_object_unref (tree_store);
+
+  return ret;
+}
+
+static void
+ui_refresh ()
+{
+  GtkTreeStore *store =
+      GTK_TREE_STORE (gtk_tree_view_get_model (GTK_TREE_VIEW (ui_tree)));
+  gtk_tree_store_clear (store);
+  if (filename)
+    gtk_window_set_title (GTK_WINDOW (ui_main_window), filename->str);
+}
+
+static int
+ui_create ()
+{
+  int ret = 0;
+
+  ui_glade_xml = glade_xml_new ("MetadataEditorMain.glade", NULL, NULL);
+
+  if (!ui_glade_xml) {
+    fprintf (stderr, "glade_xml_new failed\n");
+    ret = -101;
+    goto done;
+  }
+
+  ui_main_window = glade_xml_get_widget (ui_glade_xml, "windowMain");
+
+  ui_drawing = glade_xml_get_widget (ui_glade_xml, "drawingMain");
+
+  ui_tree = glade_xml_get_widget (ui_glade_xml, "treeMain");
+
+  ui_entry_insert_tag =
+      GTK_ENTRY (glade_xml_get_widget (ui_glade_xml, "entryTag"));
+
+  ui_entry_insert_value =
+      GTK_ENTRY (glade_xml_get_widget (ui_glade_xml, "entryValue"));
+
+  if (!(ui_main_window && ui_drawing && ui_tree && ui_entry_insert_tag
+          && ui_entry_insert_value)) {
+    fprintf (stderr, "Some widgets couldn't be created\n");
+    ret = -105;
+    goto done;
+  }
+
+  glade_xml_signal_autoconnect (ui_glade_xml);
+
+  ui_setup_tree_view (GTK_TREE_VIEW (ui_tree));
+
+  ui_refresh ();
+
+  gtk_widget_show_all (ui_main_window);
+
+done:
+
+  return ret;
+
+}
+
+/*
+ * GStreamer functions
+ */
+
+
+static gboolean
+me_gst_bus_callback_encode (GstBus * bus, GstMessage * message, gpointer data)
+{
+  gint *encode_status = (gint *) data;
+
+  fflush (stdout);
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+    {
+      GError *err;
+      gchar *debug;
+
+      gst_message_parse_error (message, &err, &debug);
+      fprintf (stderr, "Error: %s\n", err->message);
+      g_error_free (err);
+      g_free (debug);
+
+      *encode_status = ENC_ERROR;
+      gtk_main_quit ();
+    }
+      break;
+    case GST_MESSAGE_TAG:
+    {
+      /* ignore, we alredy have the tag list */
+    }
+      break;
+    case GST_MESSAGE_EOS:
+    {
+      *encode_status = ENC_DONE;
+      gtk_main_quit ();
+    }
+      break;
+    default:
+      /* unhandled message */
+      break;
+  }
+
+  /* we want to be notified again the next time there is a message
+   * on the bus, so returning TRUE (FALSE means we want to stop watching
+   * for messages on the bus and our callback should not be called again)
+   */
+  return TRUE;
+}
+
+static gboolean
+me_gst_bus_callback_view (GstBus * bus, GstMessage * message, gpointer data)
+{
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_ERROR:
+    {
+      GError *err;
+      gchar *debug;
+
+      gst_message_parse_error (message, &err, &debug);
+      fprintf (stderr, "Error: %s\n", err->message);
+      g_error_free (err);
+      g_free (debug);
+
+      gtk_main_quit ();
+    }
+      break;
+    case GST_MESSAGE_TAG:
+    {
+      if (tag_list == NULL)
+        gst_message_parse_tag (message, &tag_list);
+      else {
+        GstTagList *tl = NULL;
+        GstTagList *ntl = NULL;
+
+        gst_message_parse_tag (message, &tl);
+        if (tl) {
+          ntl = gst_tag_list_merge (tag_list, tl, GST_TAG_MERGE_PREPEND);
+          if (ntl) {
+            gst_tag_list_free (tag_list);
+            tag_list = ntl;
+            gst_tag_list_free (tl);
+          }
+        }
+      }
+      /* remove whole chunk tags */
+      gst_tag_list_remove_tag (tag_list, "exif");
+      gst_tag_list_remove_tag (tag_list, "iptc");
+      gst_tag_list_remove_tag (tag_list, "xmp");
+    }
+      break;
+    case GST_MESSAGE_EOS:
+      if (tag_list) {
+        gst_tag_list_foreach (tag_list, insert_tag_on_tree, ui_tree);
+      }
+      break;
+    default:
+      /* unhandled message */
+      break;
+  }
+
+  /* we want to be notified again the next time there is a message
+   * on the bus, so returning TRUE (FALSE means we want to stop watching
+   * for messages on the bus and our callback should not be called again)
+   */
+  return TRUE;
+}
+
+static void
+me_gst_cleanup_elements ()
+{
+  /* when adding an element to pipeline rember to set it to NULL or add extra ref */
+
+  if (gst_source) {
+    gst_object_unref (gst_source);
+    gst_source = NULL;
+  }
+  if (gst_metadata_demux) {
+    gst_object_unref (gst_metadata_demux);
+    gst_metadata_demux = NULL;
+  }
+  if (gst_metadata_mux) {
+    gst_object_unref (gst_metadata_mux);
+    gst_metadata_mux = NULL;
+  }
+  if (gst_image_dec) {
+    gst_object_unref (gst_image_dec);
+    gst_image_dec = NULL;
+  }
+  if (gst_video_scale) {
+    gst_object_unref (gst_video_scale);
+    gst_video_scale = NULL;
+  }
+  if (gst_video_convert) {
+    gst_object_unref (gst_video_convert);
+    gst_video_convert = NULL;
+  }
+  if (gst_video_sink) {
+    gst_object_unref (gst_video_sink);
+    gst_video_sink = NULL;
+  }
+  if (gst_file_sink) {
+    gst_object_unref (gst_file_sink);
+    gst_file_sink = NULL;
+  }
+
+  if (gst_pipeline) {
+    gst_element_set_state (gst_pipeline, GST_STATE_NULL);
+    gst_element_get_state (gst_pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
+    gst_object_unref (gst_pipeline);
+    gst_pipeline = NULL;
+  }
+
+}
+
+/* dummy function that looks the file extension */
+static gboolean
+is_png (const gchar * filename)
+{
+  gboolean ret = FALSE;
+  guint32 len;
+
+  if (!filename)
+    goto done;
+
+  if ((len = strlen (filename)) < 4)    /* at least ".png" */
+    goto done;
+
+  if (0 == strcasecmp (filename + (len - 4), ".png"))
+    ret = TRUE;
+
+done:
+
+  return ret;
+
+}
+
+static int
+me_gst_setup_encode_pipeline (const gchar * src_file, const gchar * dest_file,
+    gint * encode_status)
+{
+  int ret = 0;
+  GstBus *bus = NULL;
+  gboolean linked;
+
+  *encode_status = ENC_ERROR;
+
+  me_gst_cleanup_elements ();
+
+  /* create elements */
+  gst_source = gst_element_factory_make ("filesrc", NULL);
+  gst_metadata_demux = gst_element_factory_make ("metadataparse", NULL);
+  gst_metadata_mux = gst_element_factory_make ("metadatamux", NULL);
+  gst_file_sink = gst_element_factory_make ("filesink", NULL);
+
+
+  if (!(gst_source && gst_metadata_demux && gst_metadata_mux && gst_file_sink)) {
+    fprintf (stderr, "An element couldn't be created for ecoding\n");
+    ret = -300;
+    goto done;
+  }
+
+
+  /* create gst_pipeline */
+  gst_pipeline = gst_pipeline_new (NULL);
+
+  if (NULL == gst_pipeline) {
+    fprintf (stderr, "Pipeline couldn't be created\n");
+    ret = -305;
+    goto done;
+  }
+
+  /* set elements's properties */
+  g_object_set (gst_source, "location", src_file, NULL);
+  g_object_set (gst_file_sink, "location", dest_file, NULL);
+
+  /* adding and linking elements */
+  gst_bin_add_many (GST_BIN (gst_pipeline), gst_source, gst_metadata_demux,
+      gst_metadata_mux, gst_file_sink, NULL);
+
+  linked =
+      gst_element_link_many (gst_source, gst_metadata_demux, gst_metadata_mux,
+      gst_file_sink, NULL);
+
+  /* now element are owned by pipeline (for videosink we keep a extra ref) */
+  gst_source = gst_metadata_demux = gst_file_sink = NULL;
+  gst_object_ref (gst_metadata_mux);
+
+  if (!linked) {
+    fprintf (stderr, "Elements couldn't be linked\n");
+    ret = -310;
+    goto done;
+  }
+
+  *encode_status = ENC_UNKNOWN;
+
+  /* adding message bus */
+  bus = gst_pipeline_get_bus (GST_PIPELINE (gst_pipeline));
+  gst_bus_add_watch (bus, me_gst_bus_callback_encode, encode_status);
+  gst_object_unref (bus);
+
+done:
+
+  return ret;
+
+}
+
+static int
+me_gst_setup_view_pipeline (const gchar * filename, GdkWindow * window)
+{
+  int ret = 0;
+  GstBus *bus = NULL;
+  gboolean linked;
+
+  me_gst_cleanup_elements ();
+
+  /* create elements */
+  gst_source = gst_element_factory_make ("filesrc", NULL);
+  gst_metadata_demux = gst_element_factory_make ("metadataparse", NULL);
+  /* let's do a dummy stuff to avoid decodebin */
+  if (is_png (filename))
+    gst_image_dec = gst_element_factory_make ("pngdec", NULL);
+  else
+    gst_image_dec = gst_element_factory_make ("jpegdec", NULL);
+  gst_video_scale = gst_element_factory_make ("videoscale", NULL);
+  gst_video_convert = gst_element_factory_make ("ffmpegcolorspace", NULL);
+  gst_video_sink = gst_element_factory_make ("ximagesink", NULL);
+
+  if (!(gst_source && gst_metadata_demux && gst_image_dec && gst_video_scale
+          && gst_video_convert && gst_video_sink)) {
+    fprintf (stderr, "An element couldn't be created for viewing\n");
+    ret = -400;
+    goto done;
+  }
+
+  /* create gst_pipeline */
+  gst_pipeline = gst_pipeline_new (NULL);
+
+  if (NULL == gst_pipeline) {
+    fprintf (stderr, "Pipeline couldn't be created\n");
+    ret = -405;
+    goto done;
+  }
+
+  /* set elements's properties */
+  g_object_set (gst_source, "location", filename, NULL);
+  g_object_set (gst_video_sink, "force-aspect-ratio", TRUE, NULL);
+
+
+  /* adding and linking elements */
+  gst_bin_add_many (GST_BIN (gst_pipeline), gst_source, gst_metadata_demux,
+      gst_image_dec, gst_video_scale, gst_video_convert, gst_video_sink, NULL);
+
+  linked = gst_element_link_many (gst_source, gst_metadata_demux, gst_image_dec,
+      gst_video_scale, gst_video_convert, gst_video_sink, NULL);
+
+  /* now element are owned by pipeline (for videosink we keep a extra ref) */
+  gst_source = gst_metadata_demux = gst_image_dec = gst_video_scale =
+      gst_video_convert = NULL;
+  gst_object_ref (gst_video_sink);
+
+  if (window)
+    gst_x_overlay_set_xwindow_id (GST_X_OVERLAY (gst_video_sink),
+        GDK_WINDOW_XWINDOW (window));
+
+  if (!linked) {
+    fprintf (stderr, "Elements couldn't be linked\n");
+    ret = -410;
+    goto done;
+  }
+
+  /* adding message bus */
+  bus = gst_pipeline_get_bus (GST_PIPELINE (gst_pipeline));
+  gst_bus_add_watch (bus, me_gst_bus_callback_view, NULL);
+  gst_object_unref (bus);
+
+
+done:
+
+  return ret;
+
+}
+
+int
+main (int argc, char *argv[])
+{
+  int ret = 0;
+
+  if (argc != 2) {
+    fprintf (stderr, "Give the name of a jpeg file as argument\n");
+    ret = -5;
+    goto done;
+  }
+
+  gst_init (&argc, &argv);
+  gtk_init (&argc, &argv);
+
+  /* filename for future usage (title and file name to be created) */
+  if (filename)
+    g_string_free (filename, TRUE);
+  filename = g_string_new (argv[1]);
+
+  /* create UI */
+  if ((ret = ui_create ())) {
+    goto done;
+  }
+
+  /* create pipeline */
+  me_gst_setup_view_pipeline (argv[1], ui_drawing->window);
+
+  gst_element_set_state (gst_pipeline, GST_STATE_PLAYING);
+
+  gtk_main ();
+
+done:
+
+  me_gst_cleanup_elements ();
+
+  if (tag_list) {
+    gst_tag_list_free (tag_list);
+    tag_list = NULL;
+  }
+
+  if (filename) {
+    g_string_free (filename, TRUE);
+    filename = NULL;
+  }
+
+  return ret;
+}