Bug 247704

Summary:	[AVIF Downlevels] Animated AVIF image animates only one loop
Product:	WebKit	Reporter:	Said Abou-Hallawa <sabouhallawa>
Component:	Images	Assignee:	Said Abou-Hallawa <sabouhallawa>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	changseok, sabouhallawa, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=223127 https://bugs.webkit.org/show_bug.cgi?id=248544

Description Said Abou-Hallawa 2022-11-09 15:49:34 PST

This bug happens because of the hand crafted implementation of AVIFImageReader::repetitionCount(). This was added in r275184.

1. According to https://github.com/AOMediaCodec/av1-avif/issues/73#issuecomment-803017653, libavif does not provide the repetition count.
2. macOS system frameworks do not provide the repetition count for animated AVIF.
3. Chromium just indefinitely repeats all animated AVIF frames.

So to be compatible with other browsers and image viewers, I think we need to return RepetitionCountInfinite for all animated AVIF images.

Comment 1 Radar WebKit Bug Importer 2022-11-09 15:51:55 PST

<rdar://problem/102164553>

Comment 2 Said Abou-Hallawa 2022-11-09 17:35:11 PST

Pull request: https://github.com/WebKit/WebKit/pull/6329

Comment 3 EWS 2022-11-14 12:01:54 PST

Committed 256665@main (70ff964ee191): <https://commits.webkit.org/256665@main>

Reviewed commits have been landed. Closing PR #6329 and removing active labels.