qtdemux: Factor out svmi parsing. Fix bounds checking.

Move the SVMI stereoscopic atom parsing out to a helper
function to shrink qtdemux_parse_trak a bit.

Add a bounds check that the received atom is large enough
before parsing it.

Add a note to the atom parser that svmi comes from the
MPEG-A spec 23000-11.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/634>
This commit is contained in:
Jan Schmidt 2019-05-26 01:24:54 +10:00 committed by GStreamer Merge Bot
parent 27ced4c8e6
commit e2d75939bb
2 changed files with 74 additions and 45 deletions

View file

@ -764,6 +764,8 @@ atom_ctts_free (AtomCTTS * ctts)
g_free (ctts);
}
/* svmi is specified in ISO 23000-11 (Stereoscopic video application format)
* MPEG-A */
static void
atom_svmi_init (AtomSVMI * svmi)
{

View file

@ -10725,6 +10725,75 @@ qtdemux_track_id_compare_func (QtDemuxStream ** stream1,
return (gint) (*stream1)->track_id - (gint) (*stream2)->track_id;
}
static gboolean
qtdemux_parse_stereo_svmi_atom (GstQTDemux * qtdemux, QtDemuxStream * stream,
GNode * stbl)
{
GNode *svmi;
/*parse svmi header if existing */
svmi = qtdemux_tree_get_child_by_type (stbl, FOURCC_svmi);
if (svmi) {
guint len = QT_UINT32 ((guint8 *) svmi->data);
guint32 version = QT_UINT32 ((guint8 *) svmi->data + 8);
if (!version) {
GstVideoMultiviewMode mode = GST_VIDEO_MULTIVIEW_MODE_NONE;
GstVideoMultiviewFlags flags = GST_VIDEO_MULTIVIEW_FLAGS_NONE;
guint8 frame_type, frame_layout;
guint32 stereo_mono_change_count;
if (len < 18)
return FALSE;
/* MPEG-A stereo video */
if (qtdemux->major_brand == FOURCC_ss02)
flags |= GST_VIDEO_MULTIVIEW_FLAGS_MIXED_MONO;
frame_type = QT_UINT8 ((guint8 *) svmi->data + 12);
frame_layout = QT_UINT8 ((guint8 *) svmi->data + 13) & 0x01;
stereo_mono_change_count = QT_UINT32 ((guint8 *) svmi->data + 14);
switch (frame_type) {
case 0:
mode = GST_VIDEO_MULTIVIEW_MODE_SIDE_BY_SIDE;
break;
case 1:
mode = GST_VIDEO_MULTIVIEW_MODE_ROW_INTERLEAVED;
break;
case 2:
mode = GST_VIDEO_MULTIVIEW_MODE_FRAME_BY_FRAME;
break;
case 3:
/* mode 3 is primary/secondary view sequence, ie
* left/right views in separate tracks. See section 7.2
* of ISO/IEC 23000-11:2009 */
/* In the future this might be supported using related
* streams, like an enhancement track - if files like this
* ever exist */
GST_FIXME_OBJECT (qtdemux,
"Implement stereo video in separate streams");
}
if ((frame_layout & 0x1) == 0)
flags |= GST_VIDEO_MULTIVIEW_FLAGS_RIGHT_VIEW_FIRST;
GST_LOG_OBJECT (qtdemux,
"StereoVideo: composition type: %u, is_left_first: %u",
frame_type, frame_layout);
if (stereo_mono_change_count > 1) {
GST_FIXME_OBJECT (qtdemux,
"Mixed-mono flags are not yet supported in qtdemux.");
}
stream->multiview_mode = mode;
stream->multiview_flags = flags;
}
}
return TRUE;
}
/* parse the traks.
* With each track we associate a new QtDemuxStream that contains all the info
* about the trak.
@ -10746,7 +10815,6 @@ qtdemux_parse_trak (GstQTDemux * qtdemux, GNode * trak)
GNode *esds;
GNode *tref;
GNode *udta;
GNode *svmi;
QtDemuxStream *stream = NULL;
const guint8 *stsd_data;
@ -10898,50 +10966,9 @@ qtdemux_parse_trak (GstQTDemux * qtdemux, GNode * trak)
if (!(stbl = qtdemux_tree_get_child_by_type (minf, FOURCC_stbl)))
goto corrupt_file;
/*parse svmi header if existing */
svmi = qtdemux_tree_get_child_by_type (stbl, FOURCC_svmi);
if (svmi) {
len = QT_UINT32 ((guint8 *) svmi->data);
version = QT_UINT32 ((guint8 *) svmi->data + 8);
if (!version) {
GstVideoMultiviewMode mode = GST_VIDEO_MULTIVIEW_MODE_NONE;
GstVideoMultiviewFlags flags = GST_VIDEO_MULTIVIEW_FLAGS_NONE;
guint8 frame_type, frame_layout;
/* MPEG-A stereo video */
if (qtdemux->major_brand == FOURCC_ss02)
flags |= GST_VIDEO_MULTIVIEW_FLAGS_MIXED_MONO;
frame_type = QT_UINT8 ((guint8 *) svmi->data + 12);
frame_layout = QT_UINT8 ((guint8 *) svmi->data + 13) & 0x01;
switch (frame_type) {
case 0:
mode = GST_VIDEO_MULTIVIEW_MODE_SIDE_BY_SIDE;
break;
case 1:
mode = GST_VIDEO_MULTIVIEW_MODE_ROW_INTERLEAVED;
break;
case 2:
mode = GST_VIDEO_MULTIVIEW_MODE_FRAME_BY_FRAME;
break;
case 3:
/* mode 3 is primary/secondary view sequence, ie
* left/right views in separate tracks. See section 7.2
* of ISO/IEC 23000-11:2009 */
GST_FIXME_OBJECT (qtdemux,
"Implement stereo video in separate streams");
}
if ((frame_layout & 0x1) == 0)
flags |= GST_VIDEO_MULTIVIEW_FLAGS_RIGHT_VIEW_FIRST;
GST_LOG_OBJECT (qtdemux,
"StereoVideo: composition type: %u, is_left_first: %u",
frame_type, frame_layout);
stream->multiview_mode = mode;
stream->multiview_flags = flags;
}
}
/* Parse out svmi (and later st3d/sv3d) atoms */
if (!qtdemux_parse_stereo_svmi_atom (qtdemux, stream, stbl))
goto corrupt_file;
/* parse rest of tkhd */
if (stream->subtype == FOURCC_vide) {