Am 12.07.23 um 02:20 schrieb James Zern:
On Thu, Jul 6, 2023 at 4:28 AM Thilo Borgmann <thilo.borgm...@mail.de> wrote:

From: Josef Zlomek <jo...@pex.com>

Fixes: 4907

Adds support for decoding of animated WebP.

The WebP decoder adds the animation related features according to the specs:
https://developers.google.com/speed/webp/docs/riff_container#animation
The frames of the animation may be smaller than the image canvas.
Therefore, the frame is decoded to a temporary frame,
then it is blended into the canvas, the canvas is copied to the output frame,
and finally the frame is disposed from the canvas.

The output to AV_PIX_FMT_YUVA420P/AV_PIX_FMT_YUV420P is still supported.
The background color is specified only as BGRA in the WebP file
so it is converted to YUVA if YUV formats are output.

Signed-off-by: Josef Zlomek <jo...@pex.com>
---
  Changelog               |   1 +
  libavcodec/codec_desc.c |   3 +-
  libavcodec/version.h    |   2 +-
  libavcodec/webp.c       | 714 ++++++++++++++++++++++++++++++++++++----
  4 files changed, 658 insertions(+), 62 deletions(-)

diff --git a/Changelog b/Changelog
index 3876082844..271926ed8f 100644
--- a/Changelog
+++ b/Changelog
@@ -25,6 +25,7 @@ version <next>:
  - Raw VVC bitstream parser, muxer and demuxer
  - Bitstream filter for editing metadata in VVC streams
  - Bitstream filter for converting VVC from MP4 to Annex B
+- animated WebP parser/decoder

  version 6.0:
  - Radiance HDR image support
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 4406dd8318..47a38a4036 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1259,8 +1259,7 @@ static const AVCodecDescriptor codec_descriptors[] = {
          .type      = AVMEDIA_TYPE_VIDEO,
          .name      = "webp",
          .long_name = NULL_IF_CONFIG_SMALL("WebP"),
-        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSY |
-                     AV_CODEC_PROP_LOSSLESS,
+        .props     = AV_CODEC_PROP_LOSSY | AV_CODEC_PROP_LOSSLESS,

The frames are all intra, though with animation they may be smaller
than the canvas and combined with the previous frame.

Well, which makes them in fact P-Frames.
Also leaving _INTRA_ONLY induces rendering issues for animated images.

Everything else in v3.

Thanks,
Thilo


_______________________________________________
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".

Reply via email to