On Tue, Jun 21, 2022 at 10:12 AM Vignesh Venkatasubramanian <vigne...@google.com> wrote: > > On Mon, Jun 13, 2022 at 10:17 AM James Zern > <jzern-at-google....@ffmpeg.org> wrote: > > > > On Wed, Jun 1, 2022 at 11:06 AM Vignesh Venkatasubramanian > > <vigneshv-at-google....@ffmpeg.org> wrote: > > > > > > AVIF specification allows for alpha channel as an auxiliary item (in > > > case of still images) or as an auxiliary track (in case of animated > > > images). Add support for both of these. The AVIF muxer will take > > > exactly two streams (when alpha is present) as input (first one being > > > the YUV planes and the second one being the alpha plane). > > > > > > The input has to come from two different images (one of it color and > > > the other one being alpha), or it can come from a single file > > > source with the alpha channel extracted using the "alphaextract" > > > filter. > > > > > > Example using alphaextract: > > > ffmpeg -i rgba.png -filter_complex "[0:v]alphaextract[a]" -map 0 -map > > > "[a]" -still-picture 1 avif_with_alpha.avif > > > > > > Example using two sources (first source can be in any pixel format and > > > the second source has to be in monochrome grey pixel format): > > > ffmpeg -i color.avif -i grey.avif -map 0 -map 1 -c copy > > > avif_with_alpha.avif > > > > > > The generated files pass the compliance checks in Compliance Warden: > > > https://github.com/gpac/ComplianceWarden > > > > > > libavif (the reference avif library) is able to decode the files > > > generated using this patch. > > > > > > They also play back properly (with transparent background) in: > > > 1) Chrome > > > 2) Firefox (only still AVIF, no animation support) > > > > > > Signed-off-by: Vignesh Venkatasubramanian <vigne...@google.com> > > > --- > > > libavformat/movenc.c | 188 +++++++++++++++++++++++++++++-------------- > > > libavformat/movenc.h | 4 +- > > > 2 files changed, 130 insertions(+), 62 deletions(-) > > > > > > > lgtm. > > _______________________________________________ > > ffmpeg-devel mailing list > > ffmpeg-devel@ffmpeg.org > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > > > To unsubscribe, visit link above, or email > > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > > Any more comments on this? If not can this be merged please? :) >
Another ping on this please. > -- > Vignesh -- Vignesh _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
