[FFmpeg-trac] #4876(avcodec:new): DNx100 (DNxHD CID 1260) decode produces partially corrupted picture

[FFmpeg]

#4876: DNx100 (DNxHD CID 1260) decode produces partially corrupted picture
-------------------------------------+-------------------------------------
             Reporter:  jeremy       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  avcodec      |                  Version:  git-
             Keywords:  dnxhd        |  master
  dnx100                             |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 Decoding a file for this format, support being added recently by Vittorio
 Giovara in d68705c9, results in some blocks not being decoded properly as
 per the attached screenshot.

 How to reproduce:
 {{{
 % ffmpeg -i DNxHD100_cid1260_example.mov /tmp/out.mov
 ffmpeg version N-75480-ge859a3c Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.7 (Debian 4.7.2-5)
   configuration: --enable-gpl --enable-version3 --enable-gnutls
   libavutil      55.  2.100 / 55.  2.100
   libavcodec     57.  3.100 / 57.  3.100
   libavformat    57.  2.100 / 57.  2.100
   libavdevice    57.  0.100 / 57.  0.100
   libavfilter     6.  7.100 /  6.  7.100
   libswscale      4.  0.100 /  4.  0.100
   libswresample   2.  0.100 /  2.  0.100
   libpostproc    54.  0.100 / 54.  0.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
 '/video/jbj/DNxHD100_cid1260_example.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 512
     compatible_brands: qt
     encoder         : Lavf55.48.100
   Duration: 00:00:00.37, start: 0.000000, bitrate: 99926 kb/s
     Stream #0:0(eng): Video: dnxhd (AVdn / 0x6E645641), yuv422p(pc),
 1440x1080 [SAR 4:3 DAR 16:9], 100169 kb/s, 29.97 fps, 29.97 tbr, 30k tbn,
 30k tbc (default)
     Metadata:
       handler_name    : DataHandler
 Output #0, mov, to '/tmp/out.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 512
     compatible_brands: qt
     encoder         : Lavf57.2.100
     Stream #0:0(eng): Video: mpeg4 (mp4v / 0x7634706D), yuv420p, 1440x1080
 [SAR 4:3 DAR 16:9], q=2-31, 200 kb/s, 29.97 fps, 30k tbn, 29.97 tbc
 (default)
     Metadata:
       handler_name    : DataHandler
       encoder         : Lavc57.3.100 mpeg4
 Stream mapping:
   Stream #0:0 -> #0:0 (dnxhd (native) -> mpeg4 (native))
 Press [q] to stop, [?] for help
 frame=   11 fps=0.0 q=31.0 Lsize=    2854kB time=00:00:00.36
 bitrate=63688.9kbits/s
 video:2853kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 0.034509%
 }}}


 Attached files also available at
 http://jeremy.publication.org.uk/DNxHD100_cid1260_example.mov (4.4MB
 source file)
 http://jeremy.publication.org.uk/dnx_screenshot.jpg (output screenshot)

 It was suggested this may be related to other DNxHD DCT issues
 https://bugzilla.libav.org/show_bug.cgi?id=823 (albeit related to
 encoding)

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4876>
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