[MPlayer-dev-eng] bug in demux_mkv

[Sean D'Epagnier]

Hi, I tried to play a mkv file in mplayer and I have a crash on line 2535 of
demux_mkv.c

In "demux_mkv.c" line 2520 "demux_mkv_find_track_by_num" is called. It is
called from other places as well, and as it can return NULL the return value
is tested against this in all the other locations but not this one.  With my
particular file it returns NULL then crashes on line 2535 since track is NULL.

If I specify "-aid 0" to mplayer it is able to find the track.

It would be easy enough to add a test for this and disable audio by setting
demuxer->audio->id to -2.   What I don't understand is why mplayer can't
detect the audio track (the only one in the file) and use it if "-aid" is not
specified.

I would be glad to write a patch to fix the issue, but I am not sure if I
should make mplayer auto-detect the track or require -aid 0 to be specified.


The backtrace:

#0  demux_mkv_open (demuxer=0xd0b4a0) at demux_mkv.c:2535
#1  0x00000000004fc654 in demux_open_stream (stream=0xd0aae0, file_format=0, force=0, audio_id=1,
    video_id=-1, dvdsub_id=0,
    filename=0xcf52d0 "/home/sean/BitTorrent Downloads/[KAA]_FLCL_01-06.DVD(Complete)/FLCL_01.DVD(H\264.AAC)[KAA][77D314F0].mkv") at demuxer.c:729
#2  0x00000000004fcb4d in demux_open (vs=0xd0aae0, file_format=0, audio_id=1, video_id=-1,
    dvdsub_id=0,
    filename=0xcf52d0 "/home/sean/BitTorrent Downloads/[KAA]_FLCL_01-06.DVD(Complete)/FLCL_01.DVD(H\264.AAC)[KAA][77D314F0].mkv") at demuxer.c:874
#3  0x000000000043e17d in main (argc=13674544, argv=0x7fffff9a0b88) at mplayer.c:2950


Thanks,
Sean D'Epagnier