[Ffmpeg-devel] mov files cause sigfpe

[Måns Rullgård]

Michael Niedermayer <michaelni at gmx.at> writes:

> Hi
>
> On Wed, Sep 07, 2005 at 12:20:45AM +0100, M?ns Rullg?rd wrote:
>> Michael Niedermayer <michaelni at gmx.at> writes:
>> 
>> > Hi
>> >
>> > On Tue, Sep 06, 2005 at 10:47:46PM +0100, M?ns Rullg?rd wrote:
>> >> Revision 1.86 of mov.c causes a divide by zero in
>> >> av_find_stream_info() when opening many files:
>> >> 
>> >> $ ~/src/ffmpeg/build-vanilla/ffmpeg -i NeroAVC.mp4 
>> >> ffmpeg version CVS, build 3211520, Copyright (c) 2000-2004 Fabrice Bellard
>> >>   configuration:  
>> >>   built on Sep  6 2005 21:48:41, gcc: 3.3.5-20050130 (Gentoo Linux 3.3.5.20050130-r1, ssp-3.3.5.20050130-1, pie-8.7.7.1)
>> >> Floating point exception (core dumped)
>> >> $ gdb ~/src/ffmpeg/build-vanilla/ffmpeg /scratch/core/ffmpeg.3658 
>> >> [...]
>> >> (gdb) bt
>> >> #0  0x08313be0 in __divdi3 (u=0, v=0)
>> >>     at /var/portage/tmp/portage/gcc-3.3.5.20050130-r1/work/gcc-3.3.5/gcc/libgcc2.c:551
>> >> #1  0x08312773 in av_rescale_q (a=0, bq={num = 0, den = 0}, cq=
>> >>       {num = 1, den = 1000000})
>> >>     at /home/mru/src/ffmpeg/vanilla/libavutil/mathematics.c:64
>> >> #2  0x08060bda in av_find_stream_info (ic=0x83ef0a0)
>> >>     at /home/mru/src/ffmpeg/vanilla/libavformat/utils.c:2002
>> >> #3  0x08058ed9 in opt_input_file (filename=0xbfffe8c5 "NeroAVC.mp4")
>> >>     at /home/mru/src/ffmpeg/vanilla/ffmpeg.c:3056
>> >> #4  0x0805ed89 in parse_options (argc=3, argv=0xbfffe6d4, options=0x8315540)
>> >>     at /home/mru/src/ffmpeg/vanilla/cmdutils.c:89
>> >> #5  0x08054870 in main (argc=3, argv=0x1)
>> >>     at /home/mru/src/ffmpeg/vanilla/ffmpeg.c:4506
>> >> 
>> >> The old computation of time_base is obviously flawed, but now it
>> >> doesn't get set at all.  I'm not really sure what the proper way to
>> >> fix this is.
>> >> 
>> >> The NeroAVC.mp4 file is available from
>> >> http://mru.ath.cx/samples/h264/NeroAVC.mp4.
>> >
>> > fixed
>> 
>> Excellent, it works.  Now if I could only figure out why the sound has
>> stopped working with that file...
>
> well, elaborate, here it fails with 
> [aac @ 0x83293c8]faac: frame decoding failed: Gain control not yet implemented
>
> which sounds like a faad error

It is an faad error, caused by faad being fed incorrect data.  This
file used to play properly, so something appears to have broken in the
mov demuxer.  I'll try to pin it down.

-- 
M?ns Rullg?rd
mru at inprovide.com