| Summary: | Capturing a canvas that is not in the DOM can lead to erratic frame rates or no frame emission at all | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | youenn fablet <youennf> |
| Component: | Media | Assignee: | Dan Glastonbury <djg> |
| Status: | RESOLVED FIXED | ||
| Severity: | Normal | CC: | claudio.destro, eric.carlson, kkinnunen, sabouhallawa, simon.fraser, webkit-bug-importer |
| Priority: | P2 | Keywords: | InRadar |
| Version: | WebKit Nightly Build | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
|
Description
youenn fablet
2022-05-13 05:05:20 PDT
Test case is https://jsfiddle.net/0b3dqxeg/ Hi hope this helps: in our solution, canvas with CSS fixed position works Example missing (sorry): modify the test case to: <canvas id="canvas2" style="position: fixed; bottom: 0; right: 0; width: 100px"></canvas> videos still not playing in 15.4 desktop (they show a red background and nothing else happens) I did some investigations: - CanvasCaptureMediaStreamTrack::Source::canvasChanged is correctly called each time the not-in-dom canvas is changed but it returns early due to m_canvas->renderingContext()->needsPreparationForDisplay() returning true. - Normally, the page will call updateRendering which will make the actual preparation happening, which in turn will tell CanvasCaptureMediaStreamTrack::Source to generate a frame. This is what happens when canvas is in the DOM. When canvas is not in the DOM, Page::updateRendering is not called as often and this impacts the canvas track frame rate. Pull request: https://github.com/WebKit/WebKit/pull/901 Committed r294864 (250996@main): <https://commits.webkit.org/250996@main> Reviewed commits have been landed. Closing PR #901 and removing active labels. |