[FFmpeg-trac] #4829(swscale:open): Overflows (?) in xyz -> rgb conversion
FFmpeg
trac at avcodec.org
Wed Dec 23 05:39:44 EET 2020
#4829: Overflows (?) in xyz -> rgb conversion
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Reporter: cehoyos | Owner:
Type: defect | Status: open
Priority: normal | Component: swscale
Version: git-master | Resolution:
Keywords: xyz | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Changes (by Balling):
* status: new => open
Comment:
>in fact decoded fine (at least visually)
Oh really? The only way to preserve the xyz12le stuff is rawvideo (see
last comment in #1279) and it is not lossless compared to -c:v
libopenjpeg. I.e. file produced by (-pixel_format xyz12le is needed for
libopenjpeg before https://github.com/uclouvain/openjpeg/pull/1200 is
applied):
ffmpeg -pixel_format xyz12le -c:v libopenjpeg -i frm_000127.j2c -f
rawvideo out
is not the same as:
ffmpeg -i frm_000127.j2c -f rawvideo out
has off-by-one error somewhere that breaks every 32 byte if you compare in
hex diff. It is kind of hard for me to say what decoder is correct.
>a png with massive artefacts (posterization) in the top left
So what? Of course, the artifacts can be in original xyz12le file.
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Ticket URL: <https://trac.ffmpeg.org/ticket/4829#comment:3>
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