matroska: Support V_QUICKTIME as written in the specification

Message ID 20160316140352.CE1B55DAD6@aruru.libav.org
State New
Headers show

Commit Message

Janne Grunau March 16, 2016, 2:03 p.m.
Module: libav
Branch: master
Commit: 8b4b1c1eea9daa4e2003aa0935e73f56aab8102d

Author:    Luca Barbato <lu_zero@gentoo.org>
Committer: Luca Barbato <lu_zero@gentoo.org>
Date:      Sat Mar 12 13:46:13 2016 +0100

matroska: Support V_QUICKTIME as written in the specification

Check if the size is written the first 4 bytes and read the next 4
as fourcc candidate, fallback checking the initial for 4 bytes.

"The CodecPrivate contains all additional data that is stored in the
'stsd' (sample description) atom in the QuickTime file after the
mandatory video descriptor structure (starting with the size and FourCC
fields)"

CC: libav-stable@libav.org

---

 libavformat/matroskadec.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Patch

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 0ed56af..75ac67c 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1661,9 +1661,16 @@  static int matroska_parse_tracks(AVFormatContext *s)
         } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
                    (track->codec_priv.size >= 86)          &&
                    (track->codec_priv.data)) {
-            track->video.fourcc = AV_RL32(track->codec_priv.data);
-            codec_id            = ff_codec_get_id(ff_codec_movvideo_tags,
-                                                  track->video.fourcc);
+            if (track->codec_priv.size == AV_RB32(track->codec_priv.data)) {
+                track->video.fourcc = AV_RL32(track->codec_priv.data + 4);
+                codec_id            = ff_codec_get_id(ff_codec_movvideo_tags,
+                                                      track->video.fourcc);
+            }
+            if (codec_id == AV_CODEC_ID_NONE) {
+                track->video.fourcc = AV_RL32(track->codec_priv.data);
+                codec_id            = ff_codec_get_id(ff_codec_movvideo_tags,
+                                                      track->video.fourcc);
+            }
             if (codec_id == AV_CODEC_ID_NONE) {
                 char buf[32];
                 av_get_codec_tag_string(buf, sizeof(buf), track->video.fourcc);