Bug 258137 - Layer-backed GIF image animate improperly or flicker on Intel macOS 14 machines when bitmap-backend based ImageBuffer is used.
Summary: Layer-backed GIF image animate improperly or flicker on Intel macOS 14 machin...
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari 17
Hardware: Mac (Intel) Other
: P3 Normal
Assignee: Nobody
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2023-06-15 08:15 PDT by Ethan Wong
Modified: 2023-06-24 23:13 PDT (History)
6 users (show)

See Also:

Attachments
A web page to reproduce this issue (378.73 KB, application/zip)
2023-06-15 08:15 PDT, Ethan Wong 		no flags Details
The screen recording for this issue (9.40 MB, video/quicktime)
2023-06-15 08:17 PDT, Ethan Wong 		no flags Details
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Description Ethan Wong 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.
Comment 1 Ethan Wong 2023-06-15 08:17:08 PDT 
Created attachment 466704 [details]
The screen recording for this issue
Comment 2 Radar WebKit Bug Importer 2023-06-22 08:16:15 PDT 
<rdar://problem/111161156>
Comment 3 Ethan Wong 2023-06-24 23:13:58 PDT 
This issue could still be reproduced in macOS 14.0 Developer Beta 2 (23A5276g).