[FFmpeg-devel] [PATCH v4 0/7] webp: add support for animated WebP decoding

[James Zern]

On Thu, Jul 27, 2023 at 4:29 AM Thilo Borgmann <thilo.borgmann at mail.de> wrote:
>
> Am 25.07.23 um 22:14 schrieb James Zern:
> > On Tue, Jul 25, 2023 at 1:58 AM Thilo Borgmann <thilo.borgmann at mail.de> wrote:
> >>
> >> Still images fixed from v2. Now includes a fate test for animated webp.
> >>
> >> Patch 5/7 is still there for making changes in lavc/webp reviewable but
> >> shall be stashed when pushing.
> >>
> >> -Thilo
> >>
> >>
> >> Josef Zlomek (2):
> >>    libavcodec/webp: add support for animated WebP decoding
> >>    libavformat/webp: add WebP demuxer
> >>
> >> Thilo Borgmann (5):
> >>    avcodec/webp: move definitions into header
> >>    avcodec/webp: remove unused definitions
> >>    avcodec/webp_parser: parse each frame into one packet
> >>    avcodec/webp: make init_canvas_frame static
> >>    fate: add test for animated WebP
> >>
> >>   Changelog                                   |   2 +
> >>   doc/demuxers.texi                           |  28 +
> >>   libavcodec/codec_desc.c                     |   3 +-
> >>   libavcodec/version.h                        |   2 +-
> >>   libavcodec/webp.c                           | 715 +++++++++++++++++--
> >>   libavcodec/webp.h                           |  38 +
> >>   libavcodec/webp_parser.c                    | 130 ++--
> >>   libavformat/Makefile                        |   1 +
> >>   libavformat/allformats.c                    |   1 +
> >>   libavformat/version.h                       |   2 +-
> >>   libavformat/webpdec.c                       | 733 ++++++++++++++++++++
> >>   tests/fate/image.mak                        |   3 +
> >>   tests/ref/fate/exif-image-webp              |  12 +-
> >>   tests/ref/fate/webp-anim                    |  22 +
> >>   tests/ref/fate/webp-rgb-lena-lossless       |   2 +-
> >>   tests/ref/fate/webp-rgb-lena-lossless-rgb24 |   2 +-
> >>   tests/ref/fate/webp-rgb-lossless            |   2 +-
> >>   tests/ref/fate/webp-rgb-lossy-q80           |   2 +-
> >>   tests/ref/fate/webp-rgba-lossless           |   2 +-
> >>   tests/ref/fate/webp-rgba-lossy-q80          |   2 +-
> >>   20 files changed, 1589 insertions(+), 115 deletions(-)
> >>   create mode 100644 libavcodec/webp.h
> >>   create mode 100644 libavformat/webpdec.c
> >>   create mode 100644 tests/ref/fate/webp-anim
> >>
> >
> > This series is lgtm. There are still a few edge cases where
>
> > 1) the
> > 'Canvas change detected' warning will be triggered with valid files,
>
> As long as the canvas in frame threading is bound to a ThreadFrame, we can't reallocate for changes.
> Wouldn't want to touch that until the new threading is all done.
>
>
> > 2) corrupt / truncated files will produce output where they would fail
> > with libwebp and
>
> We might bail out as well though AFAICT we usually try to decode whatever might be possible.
>
>
> > 3) I see quite a few "[webp @ 0x7f5530008c00]
> > Multiple ff_thread_finish_setup() calls", not sure if that's expected.
>
> Which sample you're looking at?
>
> If I can reproduce this, I'll look at it. The other things I'd keep as they are.
>

I see this with:
https://www.gstatic.com/webp/gallery3/1_webp_a.webp
Using an animation it seems to be output once per frame.