[FFmpeg-trac] #2290(undetermined:new): Apparently wrong bitdepth set for RGBA PNG in mov

[FFmpeg]

#2290: Apparently wrong bitdepth set for RGBA PNG in mov
-------------------------------------+-------------------------------------
             Reporter:  rmk          |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 I transcoded an PNG(RGBA)-Mov sample again into PNG(RGBA)-Mov and the
 resulting file is displayed as RGBA and when I export a png frame from
 the resulting file, transparency is still there. However, when using
 the ffmpeg-generated file in Final Cut, transparency is gone (works
 with original). Comparing the atom structure I saw that the
 ffmpeg-generated file has a depth of 24 in the stsd atom, while the
 original file has 32. Changing the value to 32 in the atom makes FCP
 work with the file as expected.

 When I just remux the file, 32 is preserved.

 command line and output:

 ffmpeg -i in.mov -vcodec png out.mov
 ffmpeg version N-50095-gb9237aa Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Feb 20 2013 12:09:22 with llvm-gcc 4.2.1 (LLVM build
 2336.11.00)
   configuration:
   libavutil      52. 17.102 / 52. 17.102
   libavcodec     54. 92.100 / 54. 92.100
   libavformat    54. 63.100 / 54. 63.100
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 38.103 /  3. 38.103
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'in.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 512
     compatible_brands: qt
     encoder         : Lavf54.63.100
   Duration: 00:00:00.04, start: 0.000000, bitrate: 10307 kb/s
     Stream #0:0(eng): Video: png (png  / 0x20676E70), rgba, 1920x1080
 [SAR 1:1 DAR 16:9], 10162 kb/s, 25 fps, 25 tbr, 12800 tbn, 12800 tbc
     Metadata:
       handler_name    : DataHandler
 Output #0, mov, to 'out.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 512
     compatible_brands: qt
     encoder         : Lavf54.63.100
     Stream #0:0(eng): Video: png (png  / 0x20676E70), rgba, 1920x1080
 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 12800 tbn, 25 tbc
     Metadata:
       handler_name    : DataHandler
 Stream mapping:
   Stream #0:0 -> #0:0 (png -> png)
 Press [q] to stop, [?] for help
 frame=    1 fps=0.0 q=0.0 Lsize=      50kB time=00:00:00.04
 bitrate=10307.4kbits/s
 video:50kB audio:0kB subtitle:0 global headers:0kB muxing overhead
 1.428824%

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2290>
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