[FFmpeg-devel] [PATCH] avformat/concatdec: Check that the opened file contains a stream.

[Nicolas George]

Le duodi 12 prairial, an CCXXIII, Michael Niedermayer a écrit :
> Fixes segfault from ticket 4350

Not ok. concat should work with files with no streams, especially if streams
can be discovered later.

The bug you are trying to fix is in mxfdec.c:

static int mxf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    ...
    /* OPAtom - clip wrapped demuxing */
    /* NOTE: mxf_read_header() makes sure nb_index_tables > 0 for OPAtom */
    st = s->streams[0];
    t = &mxf->index_tables[0];

I do not know the MXF format. If MXF files without streams are not possible,
then the correct fix is to add a check at the end of mxf_read_header().

You can reproduce the segfault without concat, just:

zsh: segmentation fault  ./ffprobe_g -show_packets /tmp/0001V004.MXF

Regards,

-- 
  Nicolas George
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