[FFmpeg-devel] Bug with zzuf file

[Michael Niedermayer]

On Mon, Jul 07, 2008 at 02:01:53PM +0100, Robert Swain wrote:
> Hello,
> 
> Diego asked me to test ffaac with the zzuf-generated
> http://www1.mplayerhq.hu/~diego/zzuf/lol-mplayer.aac . In FFmpeg,
> libfaad bails out graciously but ffaac crashes:
> 
> Program received signal SIGSEGV, Segmentation fault.
> ff_mpeg4audio_get_config (c=0x8761e44, buf=0x0, buf_size=0) at
> libavcodec/bitstream.h:658
> 658	    UPDATE_CACHE(re, s)
> (gdb) bt
> #0  ff_mpeg4audio_get_config (c=0x8761e44, buf=0x0, buf_size=0) at
> libavcodec/bitstream.h:658
> #1  0x0815c5fb in aac_decode_init (avccontext=0x8745400) at libavcodec/aac.c:741
> #2  0x080f1b42 in avcodec_open (avctx=0x8745400, codec=0x8504b00) at
> libavcodec/utils.c:831
> #3  0x08074d7f in av_find_stream_info (ic=0x873c250) at libavformat/utils.c:1760
> #4  0x0806660b in opt_input_file (filename=0xbfa026bd
> "/home/rob/samples/aac/lol-mplayer.aac") at ffmpeg.c:2756
> #5  0x08068410 in parse_options (argc=8, argv=0xbfa00f34,
> options=0x844f8c0, parse_arg_function=0x8065a50 <opt_output_file>) at
> cmdutils.c:150
> #6  0x080627dd in main (argc=8, argv=0xbfa00f34) at ffmpeg.c:3804
> 
> In aac_decode_init(), avccontext->extradata is a null pointer and
> avccontext->extradata_size is 0. I can add a check for this before
> calling (with these arguments) AudioSpecificConfig() which calls
> ff_mpeg4audio_get_config() but it seems to me that FFmpeg should
> probably bail out earlier. How should this be fixed?

I dont see where ffmpeg could bail out earlier.
extradata can contain anything "form 0 bytes to a gigabyte"

For raw AAC extradata will be NULL unless the parser or some bitstream
filter sets it to a non null value.

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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