On 29/01/2021 16:12, leo60228 wrote: > + if (st->codecpar->format == AV_PIX_FMT_PAL8) > + avio_wb32(pb, AVPALETTE_COUNT); > + else > + avio_wb32(pb, 0); Is this correct, though? GIFs encoded by things that are not libavcodec may have less than AVPALETTE_COUNT entries/colors. - Derek