Bug 258137

Summary: Layer-backed GIF image animate improperly or flicker on Intel macOS 14 machines when bitmap-backend based ImageBuffer is used.
Product: WebKit Reporter: Ethan Wong <bunnnywong>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Normal CC: bfulgham, kkinnunen, sabouhallawa, simon.fraser, webkit-bug-importer, zalan
Priority: P3 Keywords: InRadar
Version: Safari 17   
Hardware: Mac (Intel)   
OS: Other   
Attachments:
Description Flags
A web page to reproduce this issue
none
The screen recording for this issue none

Ethan Wong
Reported 2023-06-15 08:15:17 PDT
Created attachment 466703 [details] A web page to reproduce this issue Layer-backed GIF images may animate improperly or flicker. See the attached page and screen recording for this issue, the GIF image with rabbit ears animates in a wrong frame rate and may even flicker. This issue: * happens only on Intel-based machines running macOS 14 beta. * happens only when the layer's backing store is small enough so that `ImageBufferShareableMappedIOSurfaceBitmapBackend` is used. (Introduced in: https://commits.webkit.org/264004@main.) * happens when WebKit is built with both macOS 13 & 14 SDK. I'm not sure if issue is WebKit specific or it's a CoreGraphics issue.
Attachments
A web page to reproduce this issue (378.73 KB, application/zip)
2023-06-15 08:15 PDT, Ethan Wong
no flags
The screen recording for this issue (9.40 MB, video/quicktime)
2023-06-15 08:17 PDT, Ethan Wong
no flags
Ethan Wong
Comment 1 2023-06-15 08:17:08 PDT
Created attachment 466704 [details] The screen recording for this issue
Radar WebKit Bug Importer
Comment 2 2023-06-22 08:16:15 PDT
Ethan Wong
Comment 3 2023-06-24 23:13:58 PDT
This issue could still be reproduced in macOS 14.0 Developer Beta 2 (23A5276g).
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