[FFmpeg-devel] [BUG] ffmpeg crash on broken MPEG-1 file

[Panagiotis Issaris]

Hi,

When feeding a broken MPEG-1 file to ffmpeg it crashes:


213:~/build/ffmpeg takis$ gdb ./ffmpeg_g
GNU gdb 6.3.50-20050815 (Apple version gdb-573) (Fri Oct 20 15:50:43  
GMT 2006)
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This GDB was configured as "i386-apple-darwin"...Reading symbols for  
shared libraries ... done

(gdb) r -i c.mpg d.mpg
Starting program: /Users/takis/build/ffmpeg/ffmpeg_g -i c.mpg d.mpg
Reading symbols for shared libraries .. done
FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard,  
et al.
   configuration:
   libavutil version: 49.4.0
   libavcodec version: 51.40.4
   libavformat version: 51.12.1
   built on May 31 2007 17:41:03, gcc: 4.0.1 (Apple Computer, Inc.  
build 5367)
[mpeg1video @ 0x3d49c4]skipped MB in I frame at 3 1
[mpeg1video @ 0x3d49c4]skipped MB in I frame at 3 0
[mpeg1video @ 0x3d49c4]Warning MVs not available
[mpeg1video @ 0x3d49c4]concealing 300 DC, 300 AC, 300 MV errors

Seems stream 1 codec frame rate differs from container frame rate:  
inf (1/0) -> 90000.00 (90000/1)

Seems stream 2 codec frame rate differs from container frame rate:  
inf (1/0) -> 90000.00 (90000/1)

Seems stream 3 codec frame rate differs from container frame rate:  
inf (1/0) -> 90000.00 (90000/1)

Seems stream 4 codec frame rate differs from container frame rate:  
inf (1/0) -> nan (0/0)
Input #0, mpeg, from 'c.mpg':
   Duration: 22:01:52.4, start: 0.500000, bitrate: 0 kb/s
   Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 320x240, 104857 kb/ 
s, 29.97 fps(r)
   Stream #0.1[0x1e4]: Video: mpeg2video, 90000.00 fps(r)
   Stream #0.2[0x1e1]: Video: mpeg2video, 90000.00 fps(r)
   Stream #0.3[0x1e8]: Video: mpeg2video, 90000.00 fps(r)
   Stream #0.4[0x1e2]: Video: mpeg2video,   inf fps(c)

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00000000
0x000035b3 in new_video_stream (oc=0x0) at /Users/takis/src/ffmpeg/ 
ffmpeg.c:2768
2768                video_enc->time_base.den= best->num;
(gdb)

I uploaded the sample to incoming.mplayerhq.hu/MPlayer/incoming/c.mpg

Oh yes, the crash occurred on MacOS/X using GCC 4.0.1.

With friendly regards,
Takis

PS: Marc, the sample was generated using zzuf :)