gst/qtdemux/: Process 'ctts' atoms, which are present in AVC ISO files (.mov files with h264 video).

Original commit message from CVS:
* gst/qtdemux/qtdemux.c: (gst_qtdemux_prepare_current_sample),
(gst_qtdemux_chain), (qtdemux_parse_samples):
* gst/qtdemux/qtdemux_dump.c: (qtdemux_dump_ctts):
* gst/qtdemux/qtdemux_dump.h:
* gst/qtdemux/qtdemux_fourcc.h:
* gst/qtdemux/qtdemux_types.c:
Process 'ctts' atoms, which are present in AVC ISO files (.mov files
with h264 video).
Use the offset present in 'ctts' to calculate the PTS for each packet
and set the PTS on outgoing buffers.
Fixes #423283

1 files changed, 30 insertions, 4 deletions

diff --git a/gst/qtdemux/qtdemux.c b/gst/qtdemux/qtdemux.c
index 3b527fac..aca5bd32 100644
--- a/gst/qtdemux/qtdemux.c
+++ b/gst/qtdemux/qtdemux.c
@@ -88,6 +88,7 @@ struct _QtDemuxSample
   guint32 chunk;
   guint32 size;
   guint64 offset;
+  GstClockTimeDiff pts_offset;  /* Add this value to timestamp to get the pts */
   guint64 timestamp;            /* In GstClockTime */
   guint64 duration;             /* in GstClockTime */
   gboolean keyframe;            /* TRUE when this packet is a keyframe */
@@ -1147,9 +1148,9 @@ gst_qtdemux_prepare_current_sample (GstQTDemux * qtdemux,
   /* now get the info for the sample we're at */
   sample = &stream->samples[stream->sample_index];
 
+  *timestamp = sample->timestamp + sample->pts_offset;
   *offset = sample->offset;
   *size = sample->size;
-  *timestamp = sample->timestamp;
   *duration = sample->duration;
   *keyframe = stream->all_keyframe || sample->keyframe;
 
@@ -1687,9 +1688,15 @@ gst_qtdemux_chain (GstPad * sinkpad, GstBuffer * inbuf)
         GST_DEBUG_OBJECT (demux, "stream : %" GST_FOURCC_FORMAT,
             GST_FOURCC_ARGS (stream->fourcc));
 
-        GST_BUFFER_TIMESTAMP (outbuf) =
-            stream->samples[stream->sample_index].timestamp;
-        demux->last_ts = GST_BUFFER_TIMESTAMP (outbuf);
+        if (stream->samples[stream->sample_index].pts_offset) {
+          demux->last_ts = stream->samples[stream->sample_index].timestamp;
+          GST_BUFFER_TIMESTAMP (outbuf) = demux->last_ts +
+              stream->samples[stream->sample_index].pts_offset;
+        } else {
+          GST_BUFFER_TIMESTAMP (outbuf) =
+              stream->samples[stream->sample_index].timestamp;
+          demux->last_ts = GST_BUFFER_TIMESTAMP (outbuf);
+        }
         GST_BUFFER_DURATION (outbuf) =
             stream->samples[stream->sample_index].duration;
 
@@ -2265,6 +2272,7 @@ qtdemux_parse_samples (GstQTDemux * qtdemux, QtDemuxStream * stream,
   GNode *co64;
   GNode *stts;
   GNode *stss;
+  GNode *ctts;
   const guint8 *stsc_data, *stsz_data, *stco_data;
   int sample_size;
   int sample_index;
@@ -2481,6 +2489,24 @@ qtdemux_parse_samples (GstQTDemux * qtdemux, QtDemuxStream * stream,
       }
     }
   }
+
+  /* composition time to sample */
+  if ((ctts = qtdemux_tree_get_child_by_type (stbl, FOURCC_ctts))) {
+    const guint8 *ctts_data = (const guint8 *) ctts->data;
+    guint32 n_entries = QT_UINT32 (ctts_data + 12);
+    guint32 count;
+    gint32 soffset;
+
+    /* Fill in the pts_offsets */
+    for (i = 0, j = 0; (j < stream->n_samples) && (i < n_entries); i++) {
+      count = QT_UINT32 (ctts_data + 16 + i * 8);
+      soffset = QT_UINT32 (ctts_data + 20 + i * 8);
+      for (k = 0; k < count; k++, j++) {
+        /* we operate with very small soffset values here, it shouldn't overflow */
+        samples[j].pts_offset = soffset * GST_SECOND / stream->timescale;
+      }
+    }
+  }
 done:
   return TRUE;