Change the default panning mode from HRTF to equal-power

The HRTF panner uses significant memory for the responses and requires a fair amount of processing to implement. For low-end mobile devices, this can be an issue. Since the default panner model is HRTF, the creation of the panner can cause the responses to be loaded.

Perhaps the default should be changed to equalpower, which doesn't consume significant memory and is much less intensive in processing power.

This is an incompatible change with the current spec.

See also: https://github.com/WebAudio/web-audio-api/issues/368

BUG=424356
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=183925

[hongchan, 2014-10-17 17:23:14]

hongchan@chromium.org changed reviewers:
+ rtoy@chromium.org

[Raymond Toy, 2014-10-17 17:39:30]

Just a few nits.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/panner-...
File LayoutTests/webaudio/panner-loop.html (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/panner-...
LayoutTests/webaudio/panner-loop.html:64: panner.panningModel = 'HRTF';
If you don't do this, will the test fail? I don't think the model really matters
for this test, so I would just remove this and the comment.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
File LayoutTests/webaudio/pannernode-basic.html (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
LayoutTests/webaudio/pannernode-basic.html:29: if (panner.numberOfInputs === 1)
I don't see what's different here? Did you delete some spaces or a blank line?

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
LayoutTests/webaudio/pannernode-basic.html:49: 
Did you remove a blank line here? (And same comment for similar changes below.)

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
File LayoutTests/webaudio/resources/panner-model-testing.js (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
LayoutTests/webaudio/resources/panner-model-testing.js:51:
panner[k].panningModel = "equalpower";
I would just remove the comment and the assignment.  If somebody in the future
changes the default panning model, this will be caught here and in the other
layout test where you check that the default model is "equalpower"

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
LayoutTests/webaudio/resources/panner-model-testing.js:97: 
Removing more blank lines?

[hongchan, 2014-10-17 18:13:41]

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/panner-...
File LayoutTests/webaudio/panner-loop.html (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/panner-...
LayoutTests/webaudio/panner-loop.html:64: panner.panningModel = 'HRTF';
On 2014/10/17 17:39:30, Raymond Toy wrote:
> If you don't do this, will the test fail? I don't think the model really
matters
> for this test, so I would just remove this and the comment.

Done.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
File LayoutTests/webaudio/pannernode-basic.html (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
LayoutTests/webaudio/pannernode-basic.html:29: if (panner.numberOfInputs === 1)
On 2014/10/17 17:39:30, Raymond Toy wrote:
> I don't see what's different here? Did you delete some spaces or a blank line?

Yes, I deleted trailing spaces and indents on empty lines.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/pannern...
LayoutTests/webaudio/pannernode-basic.html:49: 
On 2014/10/17 17:39:30, Raymond Toy wrote:
> Did you remove a blank line here? (And same comment for similar changes
below.)

Yes.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
File LayoutTests/webaudio/resources/panner-model-testing.js (right):

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
LayoutTests/webaudio/resources/panner-model-testing.js:51:
panner[k].panningModel = "equalpower";
On 2014/10/17 17:39:30, Raymond Toy wrote:
> I would just remove the comment and the assignment.  If somebody in the future
> changes the default panning model, this will be caught here and in the other
> layout test where you check that the default model is "equalpower"

Done.

https://codereview.chromium.org/652073003/diff/1/LayoutTests/webaudio/resourc...
LayoutTests/webaudio/resources/panner-model-testing.js:97: 
On 2014/10/17 17:39:30, Raymond Toy wrote:
> Removing more blank lines?

Yes.

[Raymond Toy, 2014-10-17 18:33:05]

lgtm with nits.

Since it now looks like panner-loop.html and panner-model-testing.js are
unchanged except for the blanks that were removed, just revert all of those
changes. The changes to pannernode-basic.html are ok, though, including the
changes for blanks.

[hongchan, 2014-10-17 18:39:45]

Unnecessary changes are reverted.

[hongchan, 2014-10-17 18:51:28]

The CQ bit was checked by hongchan@chromium.org

[commit-bot: I haz the power, 2014-10-17 18:52:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/652073003/40001

[commit-bot: I haz the power, 2014-10-17 19:55:21]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-17 19:55:23]

Try jobs failed on following builders:
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[hongchan, 2014-10-17 21:29:44]

The CQ bit was checked by hongchan@chromium.org

[commit-bot: I haz the power, 2014-10-17 21:30:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/652073003/40001

[commit-bot: I haz the power, 2014-10-17 21:31:43]

Committed patchset #3 (id:40001) as 183925