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mxfdemux: Implement keyframe detection for MPEG4 video streams

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This commit is contained in:
Sebastian Dröge 2009-02-06 11:09:11 +01:00
parent 0d8099685d
commit f529a4c6b3
1 changed files with 45 additions and 0 deletions
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45
gst/mxf/mxfmpeg.c
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@ -307,6 +307,45 @@ mxf_mpeg_is_mpeg2_keyframe (GstBuffer * buffer)
return FALSE;
}
static gboolean
mxf_mpeg_is_mpeg4_keyframe (GstBuffer * buffer)
{
GstByteReader reader = GST_BYTE_READER_INIT_FROM_BUFFER (buffer);
guint32 tmp;
while (gst_byte_reader_get_remaining (&reader) > 3) {
if (gst_byte_reader_peek_uint24_be (&reader, &tmp) && tmp == 0x000001) {
guint8 type;
/* Found sync code */
gst_byte_reader_skip (&reader, 3);
if (!gst_byte_reader_get_uint8 (&reader, &type))
break;
if (type == 0xb6) {
guint8 pic_type;
if (!gst_byte_reader_get_uint8 (&reader, &pic_type))
break;
pic_type = (pic_type >> 6) & 0x03;
if (pic_type == 0) {
return TRUE;
} else {
return FALSE;
}
}
} else {
gst_byte_reader_skip (&reader, 1);
}
}
g_assert_not_reached ();
return FALSE;
}
static GstFlowReturn
mxf_mpeg_video_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
GstCaps * caps, MXFMetadataTimelineTrack * track,
@ -330,6 +369,12 @@ mxf_mpeg_video_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
else
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
break;
case MXF_MPEG_ESSENCE_TYPE_VIDEO_MPEG4:
if (mxf_mpeg_is_mpeg4_keyframe (buffer))
GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
break;
default:
break;