On 03.02.24 14:57, Andreas Rheinhardt wrote:
Andreas Rheinhardt:
VP8-in-WebP only uses key frame encoding (see [1]), yet this
is currently not enforced. This commit does so in order to
make output reproducible with frame-threading as the VP8 decoder's
update_thread_context is not called at all when using decoding
VP8-in-WebP (as this is unnecessary for key frame-only streams).
[1]: https://developers.google.com/speed/webp/docs/riff_container
Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
---
libavcodec/vp8.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c
index 83c60adeb0..7972775a1c 100644
--- a/libavcodec/vp8.c
+++ b/libavcodec/vp8.c
@@ -2665,7 +2665,11 @@ int vp78_decode_frame(AVCodecContext *avctx, AVFrame
*rframe, int *got_frame,
if (ret < 0)
goto err;
- if (s->actually_webp) {
+ if (!is_vp7 && s->actually_webp) {
+ // VP8 in WebP is supposed to be intra-only. Enforce this here
+ // to ensure that output is reproducible with frame-threading.
+ if (!s->keyframe)
+ return AVERROR_INVALIDDATA;
// avctx->pix_fmt already set in caller.
} else if (!is_vp7 && s->pix_fmt == AV_PIX_FMT_NONE) {
s->pix_fmt = get_pixel_format(s);
Will apply this patchset tomorrow unless there are objections.
Works as expected for me for a coupled version of the animated webp
decoder which can follow-up.
Thanks,
Thilo
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