Bug 109983 – Enhance AudioBus copyFrom() and sumFrom() to be able to handle discrete and speakers up and down-mixing

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Chris Rogers]

Enhance AudioBus copyFrom() and sumFrom() to be able to handle discrete and speakers up and down-mixing

[Chris Rogers]

Created attachment 188666 [details]
Patch

[Kenneth Russell]

Comment on attachment 188666 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=188666&action=review

Code looks reasonable to me. One question.

> Source/WebCore/platform/audio/AudioBus.cpp:373
>              channel(i)->sumFrom(sourceBus.channel(i));

Is anything else supposed to happen here? For example, zeroing the remaining destination channels?

[Chris Rogers]

Comment on attachment 188666 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=188666&action=review

>> Source/WebCore/platform/audio/AudioBus.cpp:373
>>              channel(i)->sumFrom(sourceBus.channel(i));
> 
> Is anything else supposed to happen here? For example, zeroing the remaining destination channels?

Since we're summing into the destination, we don't want to zero out the remaining channels.  You can consider that the "missing" channels are just silent channels which are being summed in.  But, since summing in silence is a NOP, there's nothing to do.  In the "copy" case, then we *do* want to zero out the channels, since copying silence is the same as calling zero()

[WebKit Review Bot]

Comment on attachment 188666 [details]
Patch

Clearing flags on attachment: 188666

Committed r143094: <http://trac.webkit.org/changeset/143094>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.