1 files changed, 134 insertions, 0 deletions
diff --git a/gst/mxf/mxfalaw.c b/gst/mxf/mxfalaw.c
new file mode 100644
index 00000000..d0bb113f
--- /dev/null
+++ b/gst/mxf/mxfalaw.c
@@ -0,0 +1,134 @@
+/* GStreamer
+ * Copyright (C) 2008 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.
+ */
+
+/* Implementation of SMPTE 388M - Mapping A-Law coded audio into the MXF
+ * Generic Container
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <string.h>
+
+#include "mxfalaw.h"
+
+GST_DEBUG_CATEGORY_EXTERN (mxf_debug);
+#define GST_CAT_DEFAULT mxf_debug
+
+gboolean
+mxf_is_alaw_audio_essence_track (const MXFMetadataTrack * track)
+{
+  guint i;
+
+  g_return_val_if_fail (track != NULL, FALSE);
+
+  if (track->descriptor == NULL)
+    return FALSE;
+
+  for (i = 0; i < track->n_descriptor; i++) {
+    MXFMetadataFileDescriptor *d = track->descriptor[i];
+    MXFUL *key = &d->essence_container;
+    /* SMPTE 388M 6.1 */
+    if (mxf_is_generic_container_essence_container_label (key) &&
+        key->u[12] == 0x02 && key->u[13] == 0x0a &&
+        (key->u[14] == 0x01 || key->u[14] == 0x02 || key->u[14] == 0x03))
+      return TRUE;
+  }
+
+  return FALSE;
+}
+
+static GstFlowReturn
+mxf_alaw_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
+    GstCaps * caps, MXFMetadataGenericPackage * package,
+    MXFMetadataTrack * track, MXFMetadataStructuralComponent * component,
+    gpointer mapping_data, GstBuffer ** outbuf)
+{
+  *outbuf = buffer;
+
+  /* SMPTE 388M 5.1 */
+  if (key->u[12] != 0x16 || (key->u[14] != 0x08 && key->u[14] != 0x09
+          && key->u[14] != 0x0a)) {
+    GST_ERROR ("Invalid A-Law essence element");
+    return GST_FLOW_ERROR;
+  }
+
+  return GST_FLOW_OK;
+}
+
+
+GstCaps *
+mxf_alaw_create_caps (MXFMetadataGenericPackage * package,
+    MXFMetadataTrack * track, GstTagList ** tags,
+    MXFEssenceElementHandler * handler, gpointer * mapping_data)
+{
+  MXFMetadataFileDescriptor *f = NULL;
+  MXFMetadataGenericSoundEssenceDescriptor *s = NULL;
+  guint i;
+  GstCaps *caps = NULL;
+
+  g_return_val_if_fail (package != NULL, NULL);
+  g_return_val_if_fail (track != NULL, NULL);
+
+  if (track->descriptor == NULL) {
+    GST_ERROR ("No descriptor found for this track");
+    return NULL;
+  }
+
+  for (i = 0; i < track->n_descriptor; i++) {
+    if (((MXFMetadataGenericDescriptor *) track->descriptor[i])->type ==
+        MXF_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR) {
+      s = (MXFMetadataGenericSoundEssenceDescriptor *) track->descriptor[i];
+      f = track->descriptor[i];
+      break;
+    } else if (((MXFMetadataGenericDescriptor *) track->
+            descriptor[i])->is_file_descriptor
+        && ((MXFMetadataGenericDescriptor *) track->descriptor[i])->type !=
+        MXF_METADATA_MULTIPLE_DESCRIPTOR) {
+      f = track->descriptor[i];
+    }
+  }
+
+  if (!f) {
+    GST_ERROR ("No descriptor found for this track");
+    return NULL;
+  }
+
+  *handler = mxf_alaw_handle_essence_element;
+
+  caps = gst_caps_new_simple ("audio/x-alaw", NULL);
+  if (s) {
+    if (s->audio_sampling_rate.n != 0 && s->audio_sampling_rate.d != 0)
+      gst_caps_set_simple (caps, "rate", G_TYPE_INT,
+          (gint) (((gdouble) s->audio_sampling_rate.n) /
+              ((gdouble) s->audio_sampling_rate.d) + 0.5), NULL);
+
+    if (s->channel_count != 0)
+      gst_caps_set_simple (caps, "channels", G_TYPE_INT, s->channel_count,
+          NULL);
+
+    /* TODO: Handle channel layout somehow? */
+  } else {
+    GST_WARNING ("Only a generic sound essence descriptor found");
+  }
+
+  return caps;
+}