[FFmpeg-trac] #2347(avcodec:closed): Recent builds regression bug - KO from 12th Feb 2013 - OK before

FFmpeg trac at avcodec.org
Mon Mar 11 17:29:06 CET 2013


#2347: Recent builds regression bug  - KO from 12th Feb 2013 - OK before
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             Reporter:  feelart     |                    Owner:
                 Type:  defect      |                   Status:  closed
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:  invalid
             Keywords:  libx264     |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by cehoyos):

 Allow me to try again:
 When converting from png (bgra) to h264, you did not specify a colour-
 space. Since you did not specify a colour-space and the colour-space of
 your input file is not supported by the encoder, FFmpeg has to choose a
 colour-space for the output file.
 x264 can be compiled either with or without support for encoding yuv444p
 (this is what I meant with "compilation options" above, I suspect this
 wasn't clear, it is not compiler-related).
 If x264 supports both yuv420p and yuv444p as colour-spaces - as appears to
 be the case with the new binaries you were testing but not the older ones
 which seem to only support yuv420p - which should be chosen? yuv444p means
 that most quality is preserved and that is why it is chosen by FFmpeg. I
 strongly believe that it is an important feature of FFmpeg that it always
 chooses the "best" colour space from a quality point of view
 automatically. See for example ticket #290 for a user request that was one
 of the causes for the implementation of the current heuristic.
 If you know in advance that quality does not matter or if you know in
 advance that you must play your output file with software that does not
 support anything else but yuv420p, then please add -pix_fmt yuv420p to
 your command line.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2347#comment:9>
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