1053011 - AudioContext currentTime is not aligned with processing blocks

Status: RESOLVED FIXED

(Core :: Web Audio, defect, P1)

Description

[Karl Tomlinson (:karlt)]

Attachment: testcase

AudioContexts process audio samples in blocks.  "block-size is defined to be 128 sample-frames".  Therefore currentTime should always correspond to block boundaries.

Part of the reason why it doesn't is the ExtraCurrentTime added in https://hg.mozilla.org/mozilla-central/rev/1424d2e16349

But I'm guessing the other and more important bug is that currentTime is not derived from mCurrentTime instead of mStateComputedTime, which is the point where processing is reached.  This means that mCurrentTime lags behind other main thread state.

Comment 1

[Paul Adenot (:padenot)]

We should investigate this again now that the refactoring has landed.

Comment 2

[Karl Tomlinson (:karlt)]

See also bug 962719 comment 10 and bug 956574 comment 24.

Comment 3

[Paul Adenot (:padenot)]

I frequency notice our clock is a bit wrong (too late, not aligned with processing blocks...). This is a pretty fundamental problem that we should fix, as it make everything better.

Comment 4

[Karl Tomlinson (:karlt)]

Attachment: MozReview Request: bug 1053011 align "extra" time on AudioContext with processing block size r?padenot

bug 1053011 align "extra" time on AudioContext with processing block size r?padenot

Comment 5

[Karl Tomlinson (:karlt)]

I'll put a patch in bug 864171 to remove AudioContext::ExtraCurrentTime().

Comment 6

[Paul Adenot (:padenot)]

Comment on attachment 8664780 [details]
MozReview Request: bug 1053011 align "extra" time on AudioContext with processing block size r?padenot

https://reviewboard.mozilla.org/r/20027/#review18313

Comment 7

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3c826002cabf

Comment 8

[Karl Tomlinson (:karlt)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/edabd5743aeb

Comment 9

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/3c826002cabf