[FFmpeg-devel] [PATCH] Fix for paletteuse to support transparency
Carl Eugen Hoyos
ceffmpeg at gmail.com
Sat Oct 7 16:53:14 EEST 2017
2017-10-06 23:23 GMT+02:00 Carl Eugen Hoyos <ceffmpeg at gmail.com>:
> 2017-10-06 22:59 GMT+02:00 Bjorn Roche <bjorn at giphy.com>:
>> libavfilter/vf_paletteuse.c | 175
> Works fine for me
I had tested with the sample from ticket #503 yesterday.
Using the following sample:
I get less nice results:
$ ffmpeg -i 300x180-Scr-f8-056alpha.flv -vframes 1 -vf palettegen pal.png
$ ffmpeg -i 300x180-Scr-f8-056alpha.flv -i pal.png -lavfi paletteuse
-vframes 1 out.png
Transparency in the output file is not correct, I wonder if the line
"if (c1 == 0 && c2 == 0" should be more something like
"if (c1 < 128 && c2 < 128)" (or with a threshold variable).
The results get worse with more frames and apng output:
Large blocks "disappear" from the output file, this looks
quite nice without your patch (but without transparency).
Thank you, Carl Eugen
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