[FFmpeg-trac] #5301(avformat:new): support PixelCrop* and DisplayWidth Display Height elements of Matroska

[FFmpeg]

#5301: support PixelCrop* and DisplayWidth Display Height elements of Matroska
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               Reporter:  dericed     |                  Owner:
                   Type:  defect      |                 Status:  new
               Priority:  normal      |              Component:  avformat
                Version:  git-master  |               Keywords:  matroska
             Blocked By:              |               Blocking:
Reproduced by developer:  0           |  Analyzed by developer:  0
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 Summary of the bug:

 The Matroska spec defines PixelCrop[Bottom|Top|Left|Right] elements as the
 value of "The number of video pixels to remove at the
 [top|bottom|left|right] of the image." Presently the values don't appear
 to be used in the display.

 For instance, the attached sample matroska_pixel_crop_test.mkv uses these
 pixel/crop/display values:
 PixelWidth 320
 PixelHeight 240
 PixelCropBottom 40
 PixelCropTop 0
 PixelCropLeft 240
 PixelCropRight 40
 DisplayWidth 320
 DisplayHeight 240

 Since the image is a 320x240 testsrc image, the display should be cropped
 so that only one color bar is shown, but instead the whole frame is
 shown/used. I suggest have a demuxer option to enable/disable the use of
 PixelCrop* elements when matroska is used.

 How to reproduce:
 {{{
 ffmpeg -i matroska_pixel_crop_test.mkv
 ffmpeg version N-44055-g6f5048f Copyright (c) 2000-2016 the FFmpeg
 developers
   built with Apple LLVM version 7.0.2 (clang-700.1.81)
   configuration: --prefix=/usr/local/Cellar/ffmpeg/HEAD --enable-shared
 --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables
 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-
 opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-
 libfreetype --enable-libfaac --enable-libass --enable-ffplay --enable-
 libopenjpeg --disable-decoder=jpeg2000 --extra-
 cflags=-I/usr/local/Cellar/openjpeg/1.5.2_1/include/openjpeg-1.5 --enable-
 nonfree --enable-vda
   libavutil      55. 19.100 / 55. 19.100
   libavcodec     57. 27.101 / 57. 27.101
   libavformat    57. 28.100 / 57. 28.100
   libavdevice    57.  0.101 / 57.  0.101
   libavfilter     6. 39.100 /  6. 39.100
   libavresample   3.  0.  0 /  3.  0.  0
   libswscale      4.  0.100 /  4.  0.100
   libswresample   2.  0.101 /  2.  0.101
   libpostproc    54.  0.100 / 54.  0.100
 Input #0, matroska,webm, from 'matroska_pixel_crop_test.mkv':
   Metadata:
     ENCODER         : Lavf57.28.100
   Duration: 00:00:01.00, start: 0.000000, bitrate: 869 kb/s
     Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv420p, 320x240, SAR
 1:1 DAR 4:3, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
     Metadata:
       ENCODER         : Lavc57.27.101 ffv1
       DURATION        : 00:00:01.000000000
 At least one output file must be specified
 }}}

 Another real-world sample with these values is available here:
 http://archive.org/download/dl.icemusic.com/ArashFt.Aysel-
 AlwaysliveEurovisionSemiFinal2009.-WwW.Myicemusic-IR.mkv. It uses:
 PixelWidth: 720
 PixelHeight: 576
 PixelCropBottom: 4
 PixelCropTop    = 0
 PixelCropLeft   = 2
 PixelCropRight  = 4
 DisplayWidth = 1024
 DisplayHeight = 576

 Thanks

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5301>
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