Segfault when decoding corrupt .gxf file
./ffmpeg_g -i pedestrians-bug001-minimal.gxf
FFmpeg version SVN-r12579, Copyright (c) 2000-2008 Fabrice Bellard, et al.
configuration: --enable-gpl --enable-pthreads --prefix=/home/pissaris/local
--enable-libx264 --extra-cflags=-I/home/pissaris/local/include
--extra-ldflags=-L/home/pissaris/local
/lib
libavutil version: 49.7.0
libavcodec version: 51.57.2
libavformat version: 52.16.0
libavdevice version: 52.0.0
built on Jun 10 2008 16:58:20, gcc: 4.1.2 20061115 (prerelease) (Debian
4.1.1-21)
[mpeg2video @ 0x850b40]skipped MB in I frame at 14 2
[mpeg2video @ 0x850b40]skipped MB in I frame at 6 3
[mpeg2video @ 0x850b40]invalid mb type in I Frame at 1 4
[mpeg2video @ 0x850b40]skipped MB in I frame at 4 5
[mpeg2video @ 0x850b40]ac-tex damaged at 3 6
[mpeg2video @ 0x850b40]invalid mb type in I Frame at 6 7
[mpeg2video @ 0x850b40]invalid mb type in I Frame at 4 8
[mpeg2video @ 0x850b40]ac-tex damaged at 0 9
[mpeg2video @ 0x850b40]skipped MB in I frame at 5 10
[mpeg2video @ 0x850b40]invalid mb type in I Frame at 5 11
[mpeg2video @ 0x850b40]skipped MB in I frame at 2 12
[mpeg2video @ 0x850b40]ac-tex damaged at 0 13
[mpeg2video @ 0x850b40]skipped MB in I frame at 1 14
[mpeg2video @ 0x850b40]slice mismatch
[mpeg2video @ 0x850b40]skipped MB in I frame at 6 16
[mpeg2video @ 0x850b40]qscale == 0
[mpeg2video @ 0x850b40]Warning MVs not available
...
[mpeg2video @ 0x850b40]invalid mb type in P Frame at 12 3
[mpeg2video @ 0x850b40]ac-tex damaged at 14 4
[mpeg2video @ 0x850b40]ac-tex damaged at 15 5
[mpeg2video @ 0x850b40]ac-tex damaged at 12 2
[mpeg2video @ 0x850b40]ac-tex damaged at 15 10
[mpeg2video @ 0x850b40]ac-tex damaged at 0 1
[mpeg2video @ 0x850b40]invalid cbp at 4 2
[mpeg2video @ 0x850b40]invalid cbp at 13 3
[mpeg2video @ 0x850b40]slice mismatch
[mpeg2video @ 0x850b40]ac-tex damaged at 18 7
[mpeg2video @ 0x850b40]invalid cbp at 14 9
[mpeg2video @ 0x850b40]ac-tex damaged at 1 14
[mpeg2video @ 0x850b40]ac-tex damaged at 2 15
[mpeg2video @ 0x850b40]ac-tex damaged at 0 16
[mpeg2video @ 0x850b40]invalid cbp at 18 17
[mpeg2video @ 0x850b40]Warning MVs not available
[mpeg2video @ 0x850b40]concealing 396 DC, 396 AC, 396 MV errors
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 47424061009952 (LWP 17018)]
0x00002b21c6324b34 in mallopt () from /lib/libc.so.6
(gdb) bt
#0 0x00002b21c6324b34 in mallopt () from /lib/libc.so.6
#1 0x00002b21c63251ee in free () from /lib/libc.so.6
#2 0x00000000007a2c01 in av_freep (arg=<value optimized out>) at
libavutil/mem.c:121
#3 0x000000000051ccb4 in MPV_common_end (s=0xce1ac0) at
libavcodec/mpegvideo.c:263
#4 0x000000000065ac2a in mpeg_decode_end (avctx=<value optimized out>) at
libavcodec/mpeg12.c:2433
#5 0x00000000004971a8 in avcodec_close (avctx=0xce5700) at
libavcodec/utils.c:972
#6 0x000000000042bbdf in av_find_stream_info (ic=0xc63490) at
libavformat/utils.c:2053
#7 0x000000000041a7e9 in opt_input_file (filename=0x7fffe4db8e26
"pedestrians-bug001-minimal.gxf") at ffmpeg.c:2746
#8 0x00000000004222fa in parse_options (argc=3, argv=0x7fffe4db79f8,
options=0x833fc0, parse_arg_function=0x41b020 <opt_output_file>) at
cmdutils.c:150
#9 0x000000000041efbf in main (argc=3, argv=0x7fffe4db79f8) at ffmpeg.c:3830
(gdb)
(gdb) frame 4
#4 0x000000000065ac2a in mpeg_decode_end (avctx=<value optimized out>) at
libavcodec/mpeg12.c:2433
2433 MPV_common_end(&s->mpeg_enc_ctx);
(gdb) list
2428 static int mpeg_decode_end(AVCodecContext *avctx)
2429 {
2430 Mpeg1Context *s = avctx->priv_data;
2431
2432 if (s->mpeg_enc_ctx_allocated)
2433 MPV_common_end(&s->mpeg_enc_ctx);
2434 return 0;
2435 }
2436
2437 AVCodec mpeg1video_decoder = {
(gdb) print s->mpeg_enc_ctx
$1 = {avctx = 0x8080808080808080, width = -2139062144, height = -2139062144,
gop_size = -2139062144, intra_only = -2139062144, bit_rate = -2139062144,
out_format = 2155905152,
h263_pred = -2139062144, h263_plus = -2139062144, h263_msmpeg4 = -2139062144,
h263_flv = -2139062144, codec_id = 2155905152, fixed_qscale = -2139062144,
encoding = -2139062144, flags = -2139062144, flags2 = -2139062144,
max_b_frames = -2139062144, luma_elim_threshold = -2139062144,
chroma_elim_threshold = -2139062144,
strict_std_compliance = -2139062144, workaround_bugs = -2139062144, codec_tag
= -2139062144, stream_codec_tag = -2139062144, pb = {bit_buf = 2155905152,
bit_left = -2139062144, buf = 0x8080808080808080
So, the s->mpeg_enc_ctx appears to be uninitialized.