gst/matroska/: Implement Dirac muxing into Matroska comforming to the spec, i.e. put all Dirac packages up to a pictu...

Original commit message from CVS:
* gst/matroska/matroska-ids.h:
* gst/matroska/matroska-mux.c: (gst_matroska_pad_free),
(gst_matroska_mux_handle_dirac_packet),
(gst_matroska_mux_write_data):
Implement Dirac muxing into Matroska comforming to the spec, i.e.
put all Dirac packages up to a picture into a Matroska block.
TODO: Implement writing of the ReferenceBlock Matroska elements,
currently the Dirac muxing is only 100% correct if Matroska version 2
is selected for muxing.

ChangeLog

@@ -1,3 +1,16 @@
+2008-11-05  Sebastian Dröge  <sebastian.droege@collabora.co.uk>
+
+	* gst/matroska/matroska-ids.h:
+	* gst/matroska/matroska-mux.c: (gst_matroska_pad_free),
+	(gst_matroska_mux_handle_dirac_packet),
+	(gst_matroska_mux_write_data):
+	Implement Dirac muxing into Matroska comforming to the spec, i.e.
+	put all Dirac packages up to a picture into a Matroska block.
+
+	TODO: Implement writing of the ReferenceBlock Matroska elements,
+	currently the Dirac muxing is only 100% correct if Matroska version 2
+	is selected for muxing.
+
 2008-11-04  Sebastian Dröge  <sebastian.droege@collabora.co.uk>
 
 	Patch by: Bastien Nocera <hadess at hadess dot net>,

gst/matroska/matroska-ids.h

@@ -517,6 +517,8 @@ typedef struct _GstMatroskaTrackVideoContext {
   gdouble       default_fps;
   GstMatroskaAspectRatioMode asr_mode;
   guint32       fourcc;
+
+  GstBuffer     *dirac_unit;
 } GstMatroskaTrackVideoContext;
 
 typedef struct _GstMatroskaTrackAudioContext {

gst/matroska/matroska-mux.c

@@ -364,6 +364,16 @@ static void
 gst_matroska_pad_free (GstMatroskaPad * collect_pad)
 {
   /* free track information */
+  if (collect_pad->track->type == GST_MATROSKA_TRACK_TYPE_VIDEO) {
+    GstMatroskaTrackVideoContext *ctx =
+        (GstMatroskaTrackVideoContext *) collect_pad->track;
+
+    if (ctx->dirac_unit) {
+      gst_buffer_unref (ctx->dirac_unit);
+      ctx->dirac_unit = NULL;
+    }
+  }
+
   if (collect_pad->track != NULL) {
     g_free (collect_pad->track->codec_id);
     g_free (collect_pad->track->codec_name);
@@ -1939,6 +1949,61 @@ gst_matroska_mux_create_buffer_header (GstMatroskaTrackContext * track,
   return hdr;
 }
 
+static GstBuffer *
+gst_matroska_mux_handle_dirac_packet (GstMatroskaMux * mux,
+    GstMatroskaPad * collect_pad, GstBuffer * buf)
+{
+  GstMatroskaTrackVideoContext *ctx =
+      (GstMatroskaTrackVideoContext *) collect_pad->track;
+  const guint8 *data = GST_BUFFER_DATA (buf);
+  guint8 parse_code;
+  GstBuffer *ret = NULL;
+
+  if (GST_BUFFER_SIZE (buf) < 13) {
+    gst_buffer_unref (buf);
+    return ret;
+  }
+
+  if (GST_READ_UINT32_BE (data) != 0x42424344) {
+    gst_buffer_unref (buf);
+    return ret;
+  }
+
+  parse_code = GST_READ_UINT8 (data + 4);
+
+  switch (parse_code) {
+    case 0x00:
+      if (ctx->dirac_unit) {
+        gst_buffer_unref (ctx->dirac_unit);
+      }
+      ctx->dirac_unit = buf;
+      break;
+    case 0x10:
+    case 0x20:
+    case 0x30:
+      if (ctx->dirac_unit)
+        ctx->dirac_unit = gst_buffer_join (ctx->dirac_unit, buf);
+      else
+        ctx->dirac_unit = buf;
+      break;
+    default:
+      /* picture */
+      if (ctx->dirac_unit) {
+        ret = gst_buffer_join (ctx->dirac_unit, gst_buffer_ref (buf));
+        ctx->dirac_unit = NULL;
+        ret = gst_buffer_make_metadata_writable (ret);
+        gst_buffer_copy_metadata (ret, buf,
+            GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS |
+            GST_BUFFER_COPY_CAPS);
+      } else {
+        ret = buf;
+      }
+      break;
+  }
+
+  return ret;
+}
+
 /**
  * gst_matroska_mux_write_data:
  * @mux: #GstMatroskaMux
@@ -1972,6 +2037,14 @@ gst_matroska_mux_write_data (GstMatroskaMux * mux, GstMatroskaPad * collect_pad)
     return GST_FLOW_OK;
   }
 
+  /* for dirac we have to queue up everything up to a picture unit */
+  if (strcmp (collect_pad->track->codec_id,
+          GST_MATROSKA_CODEC_ID_VIDEO_DIRAC) == 0) {
+    buf = gst_matroska_mux_handle_dirac_packet (mux, collect_pad, buf);
+    if (!buf)
+      return GST_FLOW_OK;
+  }
+
   /* hm, invalid timestamp (due to --to be fixed--- element upstream);
    * this would wreak havoc with time stored in matroska file */
   /* TODO: maybe calculate a timestamp by using the previous timestamp