789705 - canvas.drawImage using the output of getUserMedia sometimes fails with "Component not available"

Status: RESOLVED INVALID

(Core :: WebRTC: Audio/Video, defect)

Description

[Timothy B. Terriberry (:derf)]

canvas.drawImage using the output of getUserMedia run through a video tag sometimes fails with "Component not available". This happens very often on anant's Mac, and rarely on my Linux machine, so I suspect some kind of race condition. According to Bas, this can only happen if nsLayoutUtils::SurfaceFromElement() fails with some reason _other_ than mIsStillLoading==true. Possibly this is related to bug 771833?

Reproducible test case:

Comment 1

[Jason Smith [:jsmith]]

Related to bug 778682?

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

This demo doesn't have any code ensuring that video frames have actually arrived at the <video> element after setting video.src = stream.

The demo could wait for a "canplaythrough" event before it starts doing its drawImage(). Or, once I've fixed bug 778682, the demo could wait for a "loadeddata" event.

Comment 3

[Jason Smith [:jsmith]]

Why was this closed as invalid?

Comment 4

[Timothy B. Terriberry (:derf)]

(In reply to Jason Smith [:jsmith] from comment #3)
> Why was this closed as invalid?

I presume because the bug was in the demo (see comment 2). It could also conceivably have been duped to bug 778682.

Comment 5

[Sonny Piers [:sonny]]

yes