[FFmpeg-devel] [PATCH] mov hacks: Fix ulaw-in-mov sample.

[Reimar Döffinger]

This patch fixes the sample from trac issue #522.
One issue is that the size of the trak elements is coded
too large, so that the next trak element would be parsed
as part of the first and truncated incorrectly.
The second issue is that the mov demuxer insists on using its
calculated sample_size (which is nonsense) instead of the one
encoded in the track.
I have no idea what the correct behaviour is, a special-case
for ulaw is one way that works for this case.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
---
 libavformat/mov.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 4f79196..e1a8d87 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -319,6 +319,16 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         if (atom.size >= 8) {
             a.size = avio_rb32(pb);
             a.type = avio_rl32(pb);
+            if (atom.type != MKTAG('r','o','o','t') &&
+                atom.type != MKTAG('m','o','o','v'))
+            {
+                if (a.type == MKTAG('t','r','a','k') || a.type == MKTAG('m','d','a','t'))
+                {
+                    av_log(c->fc, AV_LOG_ERROR, "Broken file, trak/mdat not at top-level\n");
+                    avio_skip(pb, -8);
+                    return 0;
+                }
+            }
             total_size += 8;
             if (a.size == 1) { /* 64 bit extended size */
                 a.size = avio_rb64(pb) - 8;
@@ -1405,7 +1415,8 @@ int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries)
             bits_per_sample = av_get_bits_per_sample(st->codec->codec_id);
             if (bits_per_sample) {
                 st->codec->bits_per_coded_sample = bits_per_sample;
-                sc->sample_size = (bits_per_sample >> 3) * st->codec->channels;
+                if (st->codec->codec_id != CODEC_ID_PCM_MULAW)
+                    sc->sample_size = (bits_per_sample >> 3) * st->codec->channels;
             }
         } else if (st->codec->codec_type==AVMEDIA_TYPE_SUBTITLE){
             // ttxt stsd contains display flags, justification, background
-- 
1.7.9.1