On Mon, Nov 27, 2017 at 5:41 PM, Carl Eugen Hoyos <ceffm...@gmail.com> wrote:
> 2017-11-27 18:50 GMT+01:00 Bjorn Roche <bj...@giphy.com>: > > Sorry for the very delayed response, Carl: > > > > On Tue, Nov 21, 2017 at 6:55 PM, Carl Eugen Hoyos <ceffm...@gmail.com> > > wrote: > > > >> 2017-11-21 18:53 GMT+01:00 Bjorn Roche <bj...@giphy.com>: > >> > Support for transparencies in animated gifs requires modifying both > >> > libavcodec/gif.c and libavformat/gif.c because both the graphics > >> > control extension (handled by libavformat/gif.c) and the raw frame > data > >> > (handled by libavcodec/gif.c) must be changed. > >> > >> Does remuxing animated gif with transparency work with your patch? > > > > A command like this: > > > > ffmpeg -i in.gif out.gif > > > > seems to produce the same output as before: transparency replaces > > with opacity. > > remuxing == -vcodec copy > > What about ffmpeg -i in.gif -vcodec copy out.gif ? > That doesn't work. Weather I use my patch or not it aborts: Assertion video_par->format == AV_PIX_FMT_PAL8 failed at libavformat/gif.c:132 As far as I can tell, the gif decoder (which I haven't touched) outputs BGRA, but the gif writer requires PAL8. > However a command like this: > > > > ffmpeg -i in.gif -vf palettegen -y /tmp/pal.png && ffmpeg -i in.gif > > -i /tmp/pal.png -lavfi paletteuse -y -f gif out.gif > > > > produces an output that looks like the input (including transparency). > > > > I believe this is a problem with the decoder, however, since > > > > ffmpeg -i /Users/bjorn/Desktop/smoketrail.gif > > /Users/bjorn/Desktop/smoketrail-out%d.png > > This produces transparent images here for the output > file of ticket #6813. ./ffmpeg -i transparency.apng out.gif Produces the expected results (you don't see previous images "behind" the current image). bjorn -- Bjorn Roche Sr. Video Pipeline Engineer bj...@giphy.com _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
