Bug 191868

Summary:

Colours are slightly shifted when using Canvas.captureStream()

Product:

WebKit

Reporter:

Adam <adam>

Component:

WebRTC

Assignee:

Nobody <webkit-unassigned>

Status:

NEW

Severity:

Normal

CC:

ahmad.saleem792, eric.carlson, jer.noble, jonlee, simon.fraser, thorton, webkit-bug-importer, youennf

Priority:

Keywords:

InRadar

Version:

Safari 12

Hardware:

Mac

OS:

macOS 10.13

Attachments:

Description	Flags
Canvas and Video element with 2 slightly different colours	none

Adam

Reported 2018-11-20 15:33:32 PST

Created attachment 355368 [details] Canvas and Video element with 2 slightly different colours If you draw on a canvas and use canvas.captureStream the resulting colours in the video are slightly different than the colours on the Canvas. This is also the case a bit in Chrome and Firefox but in Safari it is quite a bit different. See https://output.jsbin.com/rebesum where a new random colour is drawn every 1 second on both a Canvas and a Video. It's more noticeable with some colours than others.

Attachments
Canvas and Video element with 2 slightly different colours (55.38 KB, image/png) 2018-11-20 15:33 PST, Adam	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Radar WebKit Bug Importer

Comment 1 2018-11-20 18:42:52 PST

<rdar://problem/46193273>

Ahmad Saleem

Comment 2 2022-06-02 05:52:19 PDT

I think there is no more color shift in the attached JSBin test case in Safari 15.5 on macOS 12.4. As for matching with other browsers, Chrome Canary 104 does not show <video> element at all while Firefox 104 just shows static colour for <video> tag, which becomes out of sync with <canvas> element. I am not sure what is correct behavior according to spec but this is the latest update. Thanks!

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