[FFmpeg-trac] #11002(avformat:closed): Unnecessary PNG metadata generated

[FFmpeg]

#11002: Unnecessary PNG metadata generated
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             Reporter:               |                    Owner:  (none)
  MasterQuestionable                 |
                 Type:  enhancement  |                   Status:  closed
             Priority:  normal       |                Component:  avformat
              Version:  git-master   |               Resolution:  invalid
             Keywords:  png          |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Changes (by Balling):

 * status:  new => closed
 * resolution:   => invalid

Comment:

 >No use for most implementations.

 Main implementations: Chrome, Gimp, Firefox support gAMA and cHRM. As for
 CICP that is a future standard, that is needed for BT.709 transfer support
 (very different from sRGB) and PQ HDR. Also gAMA needed for 2.2 vs sRGB.
 Also image magik reads them.


 Adobe Photoshop admits it is a bug that they do not read gAMA and cHRM.

 Finally even if it was true that no code reads it, the PNG spec requires
 to write fallback for ICC lrofiles and sRGB chunk, fallback being gAMA and
 cHRM.
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Ticket URL: <https://trac.ffmpeg.org/ticket/11002#comment:2>
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