[FFmpeg-trac] #6256(undetermined:new): Showpalette filter returns default palette for GIF.
FFmpeg
trac at avcodec.org
Thu Mar 23 16:39:26 EET 2017
#6256: Showpalette filter returns default palette for GIF.
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Reporter: mulvya | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: git-master | undetermined
Keywords: gif | Resolution:
regression | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Changes (by cehoyos):
* keywords: => gif regression
Comment:
If there were an issue, this would be a regression since
91499f4ee825502677dfc11b00205538720d0513
But FFmpeg does not guarantee to output a particular colour space for a
given file (as it does not guarantee a particular audio sample format when
decoding a given file), this behaviour isn't part of the API/ABI (this is
why API users always have to check the pix_fmt and sample_fmts that
encoders need / decoders provide). Note that decoding of the provided file
only works since f83657fc, four commits after the requested feature was
"broken" / the reported "bug" was introduced.
From FFmpeg's pov, the provided file is not palettized, to get a palette
for the given (bgra) file, using the palettegen filter is required. Using
the showpalette filter for a file that isn't palettized will show a
default filter.
Not closing yet as I don't know if changing the current behaviour of the
gif decoder / demuxer is possible or not, this may be a valid feature
request.
For future tickets: Please do not provide output files unless specifically
asked to, attaching them very often leads to confusion.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6256#comment:2>
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