Bug 75057 – Implement MediaElementAudioSourceNode::setFormat() so numberOfChannels and sampleRate are accounted for

• Component: New Bugs
• Status: RESOLVED FIXED

[Chris Rogers]

Implement MediaElementAudioSourceNode::setFormat() so numberOfChannels and sampleRate are accounted for

[Chris Rogers]

Created attachment 120248 [details]
Patch

[WebKit Review Bot]

Attachment 120248 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/update-webkit']" exit_code: 9

Updating OpenSource
First, rewinding head to replay your work on top of it...
Applying: Inform the scrolling coordinator when scrollbar layers come and go
Using index info to reconstruct a base tree...
<stdin>:474806: trailing whitespace.
        [Chromium] DatabaseTrackerChromium: iterating DatabaseSet races with Database disposal on worker thread 
<stdin>:474827: trailing whitespace.
        Nothing to test, just removing redundant code. Correct behavior tested by 
<stdin>:475346: trailing whitespace.
    
warning: 3 lines add whitespace errors.
Falling back to patching base and 3-way merge...
warning: too many files (created: 167528 deleted: 3), skipping inexact rename detection
Auto-merging LayoutTests/ChangeLog
CONFLICT (content): Merge conflict in LayoutTests/ChangeLog
Auto-merging LayoutTests/platform/chromium/test_expectations.txt
CONFLICT (content): Merge conflict in LayoutTests/platform/chromium/test_expectations.txt
Auto-merging Source/WebCore/ChangeLog
CONFLICT (content): Merge conflict in Source/WebCore/ChangeLog
Auto-merging Source/WebCore/page/ScrollingCoordinator.h
CONFLICT (content): Merge conflict in Source/WebCore/page/ScrollingCoordinator.h
Auto-merging Source/WebCore/page/mac/ScrollingCoordinatorMac.mm
CONFLICT (content): Merge conflict in Source/WebCore/page/mac/ScrollingCoordinatorMac.mm
Auto-merging Source/WebCore/platform/ScrollView.cpp
Auto-merging Source/WebCore/rendering/RenderLayerCompositor.cpp
CONFLICT (content): Merge conflict in Source/WebCore/rendering/RenderLayerCompositor.cpp
Auto-merging Source/WebKit2/ChangeLog
CONFLICT (content): Merge conflict in Source/WebKit2/ChangeLog
Auto-merging Tools/ChangeLog
CONFLICT (content): Merge conflict in Tools/ChangeLog
Auto-merging Tools/Scripts/build-webkit
Auto-merging Tools/Scripts/webkitdirs.pm
CONFLICT (content): Merge conflict in Tools/Scripts/webkitdirs.pm
Failed to merge in the changes.
Patch failed at 0001 Inform the scrolling coordinator when scrollbar layers come and go

When you have resolved this problem run "git rebase --continue".
If you would prefer to skip this patch, instead run "git rebase --skip".
To restore the original branch and stop rebasing run "git rebase --abort".

rebase refs/remotes/origin/master: command returned error: 1

Died at Tools/Scripts/update-webkit line 158.


If any of these errors are false positives, please file a bug against check-webkit-style.

[Eric Carlson]

Comment on attachment 120248 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=120248&action=review

> Source/WebCore/platform/audio/MultiChannelResampler.cpp:90
> +    size_t m_framesToProcess; // used to verify that all channels ask for the same amount

Nit: Comments should use proper sentences (missing capital and period).

> Source/WebCore/platform/audio/MultiChannelResampler.cpp:102
> +        OwnPtr<SincResampler> resampler = adoptPtr(new SincResampler(scaleFactor));
> +        m_kernels.append(resampler.release());

This local variable isn't necessary, it causes ref count churn.

Why doesn't SincResampler use the preferred WebKit idiom of a private constructor plus a create() method?

> Source/WebCore/platform/audio/MultiChannelResampler.cpp:108
> +    // provider can provide us with multi-channel audio data. But each of our single-channel resamplers (kernels)

Nit: Capitalize.

> Source/WebCore/platform/audio/MultiChannelResampler.h:48
> +    // FIXME: the mac port can have a more highly optimized implementation based on CoreAudio
> +    // instead of SincResampler. For now the default implementation will be used on all ports.

Please include a bug number with the FIXME.

> Source/WebCore/platform/audio/MultiChannelResampler.h:53
> +    double m_scaleFactor;

This is initialized in the constructor but never used in the code. Is it necessary?

> Source/WebCore/webaudio/MediaElementAudioSourceNode.cpp:70
> +        // FIXME: implement multi-channel greater than stereo.

Please include a bug number for the FIXME.

> Source/WebCore/webaudio/MediaElementAudioSourceNode.cpp:75
> +        if (!numberOfChannels || numberOfChannels > 2 || sourceSampleRate < minSampleRate || sourceSampleRate > maxSampleRate) {
> +            // process() will generate silence for these uninitialized values.
> +            m_sourceNumberOfChannels = 0;
> +            m_sourceSampleRate = 0;
> +            return;

It would be helpful to LOG() exactly which condition(s) trigger this so it is possible to discover why a file generates only silence.

[Chris Rogers]

Committed r103581: <http://trac.webkit.org/changeset/103581>

[Chris Rogers]

Comment on attachment 120248 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=120248&action=review

Eric, thanks for the review!

>> Source/WebCore/platform/audio/MultiChannelResampler.cpp:90
>> +    size_t m_framesToProcess; // used to verify that all channels ask for the same amount
> 
> Nit: Comments should use proper sentences (missing capital and period).

FIXED

>> Source/WebCore/platform/audio/MultiChannelResampler.cpp:102
>> +        m_kernels.append(resampler.release());
> 
> This local variable isn't necessary, it causes ref count churn.
> 
> Why doesn't SincResampler use the preferred WebKit idiom of a private constructor plus a create() method?

FIXED

I'm using the SincResampler class elsewhere as a lightweight local stack-based variable, so that's why the constructor is public.
I guess I could still add a create() method too...

>> Source/WebCore/platform/audio/MultiChannelResampler.cpp:108
>> +    // provider can provide us with multi-channel audio data. But each of our single-channel resamplers (kernels)
> 
> Nit: Capitalize.

FIXED

>> Source/WebCore/platform/audio/MultiChannelResampler.h:48
>> +    // instead of SincResampler. For now the default implementation will be used on all ports.
> 
> Please include a bug number with the FIXME.

FIXED: create bug:
https://bugs.webkit.org/show_bug.cgi?id=75118

>> Source/WebCore/platform/audio/MultiChannelResampler.h:53
>> +    double m_scaleFactor;
> 
> This is initialized in the constructor but never used in the code. Is it necessary?

Good point - I removed it.

>> Source/WebCore/webaudio/MediaElementAudioSourceNode.cpp:70
>> +        // FIXME: implement multi-channel greater than stereo.
> 
> Please include a bug number for the FIXME.

Added comment referencing:
https://bugs.webkit.org/show_bug.cgi?id=75119

>> Source/WebCore/webaudio/MediaElementAudioSourceNode.cpp:75
>> +            return;
> 
> It would be helpful to LOG() exactly which condition(s) trigger this so it is possible to discover why a file generates only silence.

Added LOG message