Opened 4 years ago

Last modified 19 months ago

#3707 new enhancement

Support decoding transparency information in dnxhd streams

Reported by: cehoyos Owned by:
Priority: wish Component: avcodec
Version: git-master Keywords: dnxhd alpha
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

http://thread.gmane.org/gmane.comp.video.ffmpeg.libav.user/13205

A user uploaded a dnxhd sample that contains transparency information (the black background is supposed to be transparent), FFmpeg reports yuv422p10le.

$ ffmpeg -i Untitled_dnhd.mov
ffmpeg version N-63852-gf341340 Copyright (c) 2000-2014 the FFmpeg developers
  built on Jun  9 2014 16:59:00 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl
  libavutil      52. 89.100 / 52. 89.100
  libavcodec     55. 66.100 / 55. 66.100
  libavformat    55. 42.101 / 55. 42.101
  libavdevice    55. 13.101 / 55. 13.101
  libavfilter     4.  7.100 /  4.  7.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 19.100 /  0. 19.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Untitled_dnhd.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2014-05-29 21:36:09
  Duration: 00:00:01.03, start: 0.000000, bitrate: 842317 kb/s
    Stream #0:0(eng): Video: dnxhd (AVdn / 0x6E645641), yuv422p10le, 1920x1080, 841432 kb/s, 29.97 fps, 29.97 tbr, 1000k tbn, 1000k tbc (default)
    Metadata:
      creation_time   : 2014-05-29 21:36:09
      handler_name    : Apple Alias Data Handler
      encoder         : DNxHD  709
At least one output file must be specified

Change History (3)

comment:2 Changed 19 months ago by richardpl

It looks like alpha is stored as raw separate 8bit plane.
Single sample is not enough.

Last edited 19 months ago by richardpl (previous) (diff)

comment:3 Changed 19 months ago by cehoyos

Additional, possibly very useful sample from forum user ils_fl uploaded.

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