[FFmpeg-trac] #4817(avformat:new): mxf encoder segfaults on 1 frame input and mpeg2 long gop video

[FFmpeg]

#4817: mxf encoder segfaults on 1 frame input and mpeg2 long gop video
-------------------------------------+-------------------------------------
               Reporter:  cus        |                  Owner:
                   Type:  defect     |                 Status:  new
               Priority:  important  |              Component:  avformat
                Version:             |               Keywords:  mxf mxfenc
  unspecified                        |  crash segfault mpeg2video
             Blocked By:             |               Blocking:
Reproduced by developer:  0          |  Analyzed by developer:  0
-------------------------------------+-------------------------------------
 Summary of the bug:

 The mxf encoder segfaults when encoding 1 mpeg2 video with bframes from an
 1 frame long source.

 How to reproduce:
 {{{
 % ./ffmpeg -f lavfi -i "testsrc=d=0.01" -f lavfi -i "aevalsrc=1:d=0.01"
 -acodec pcm_s24le -ar 48000 -bf 2 -vcodec mpeg2video out.mxf
 ffmpeg version N-74749-g648de46 Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.8 (SUSE Linux)
   configuration: --disable-vaapi --enable-vdpau --enable-gpl --enable-
 libfreetype --enable-libzvbi --enable-libass --enable-frei0r --enable-
 openssl --enable-nonfree --enable-libx264 --enable-libfdk-aac --enable-
 nonfree
   libavutil      54. 31.100 / 54. 31.100
   libavcodec     56. 59.100 / 56. 59.100
   libavformat    56. 40.101 / 56. 40.101
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 40.100 /  5. 40.100
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  2.101 /  1.  2.101
   libpostproc    53.  3.100 / 53.  3.100
 Input #0, lavfi, from 'testsrc=d=0.01':
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240
 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
 Input #1, lavfi, from 'aevalsrc=1:d=0.01':
   Duration: N/A, start: 0.000000, bitrate: 2822 kb/s
     Stream #1:0: Audio: pcm_f64le, 44100 Hz, mono, dbl, 2822 kb/s
 File 'out.mxf' already exists. Overwrite ? [y/N] y
 Output #0, mxf, to 'out.mxf':
   Metadata:
     encoder         : Lavf56.40.101
     Stream #0:0: Video: mpeg2video, yuv420p, 320x240 [SAR 1:1 DAR 4:3],
 q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
     Metadata:
       encoder         : Lavc56.59.100 mpeg2video
     Stream #0:1: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
     Metadata:
       encoder         : Lavc56.59.100 pcm_s24le
 Stream mapping:
   Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg2video (native))
   Stream #1:0 -> #0:1 (pcm_f64le (native) -> pcm_s24le (native))
 Press [q] to stop, [?] for help
 [mxf @ 0x3b16380] -d10_channelcount requires MXF D-10 and will be ignored
 Segmentation fault

 }}}

 Valgrind output:
 {{{
 ==16078== Invalid read of size 4
 ==16078==    at 0x61180F: mxf_write_packet (mxfenc.c:2451)
 ==16078==    by 0x602C1E: write_packet (mux.c:660)
 ==16078==    by 0x602C1E: av_write_trailer (mux.c:998)
 ==16078==    by 0x479859: transcode (ffmpeg.c:4016)
 ==16078==    by 0x479859: main (ffmpeg.c:4165)
 ==16078==  Address 0x180cc38860 is not stack'd, malloc'd or (recently)
 free'd
 }}}

 {{{mxf->edit_units_count}}} is zero therefore indexing with
 {{{mxf->edit_units_count-1}}} will segfault...

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4817>
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