970773 - AudioProcessingEvent playbackTime is wrong

Status: RESOLVED FIXED

(Core :: Web Audio, defect, P2)

Description

[Karl Tomlinson (:karlt)]

Attachment: processor-time.html

1. Load testcase.
2. Click start
3. Observe times

Expected: playbackTime > currentTime.
Actual: playbackTime << currentTime, depending on the time between 1 and 2.

4. In another tab, load about:memory and click "Minimize memory usage".
5. Return to testcase and click start again.

Expected: playbackTime > currentTime.
Actual: currentTime - playbackTime is greater than after 3.

Comment 1

[Andreas Gal :gal]

roc, any ideas?

Comment 2

[Karl Tomlinson (:karlt)]

The Audio Working Group is proposing replacing this API:
http://lists.w3.org/Archives/Public/public-audio/2014JulSep/0061.html

Comment 3

[Andreas Gal :gal]

This is blocking DAALA in JS on Firefox (works in every other browser).

Comment 4

[Karl Tomlinson (:karlt)]

Attachment: remove unnecessary IsSafeToRunScript() test on event loop nsRunnable

If the event loop is running, then it is safe to run script.

Comment 5

[Karl Tomlinson (:karlt)]

Attachment: remove unnecessary locking when getting AudioNodeEngine Node on main thread

See also bug 914392.

Comment 6

[Karl Tomlinson (:karlt)]

Attachment: convert destination stream time to DOM time for playbackTime

Comment 7

[Karl Tomlinson (:karlt)]

Attachment: collect common AudioProcessingEvent tests into a shared function

Comment 8

[Karl Tomlinson (:karlt)]

Attachment: failed attempt at test

currentTime is updated via a different mechanism to that of sending AudioProcessingEvents, and so can get ahead of playbackTime sometimes, particularly when things start up.

Comment 9

[Karl Tomlinson (:karlt)]

Attachment: mochitest

This test works better.

Comment 10

[Karl Tomlinson (:karlt)]

https://tbpl.mozilla.org/?tree=Try&rev=0f743833a9b6
https://tbpl.mozilla.org/?tree=Try&rev=6c47a71899a9

Comment 11

[Karl Tomlinson (:karlt)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/6bb97f50a486
https://hg.mozilla.org/integration/mozilla-inbound/rev/fc77703e2458
https://hg.mozilla.org/integration/mozilla-inbound/rev/2bebae19344e
https://hg.mozilla.org/integration/mozilla-inbound/rev/d5afae166b36
https://hg.mozilla.org/integration/mozilla-inbound/rev/ba1cdbc36bdd

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/6bb97f50a486
https://hg.mozilla.org/mozilla-central/rev/fc77703e2458
https://hg.mozilla.org/mozilla-central/rev/2bebae19344e
https://hg.mozilla.org/mozilla-central/rev/d5afae166b36
https://hg.mozilla.org/mozilla-central/rev/ba1cdbc36bdd