Bug 180040 – Web Audio's AnalyserNode.fftSize cannot be greater than 2048 in Safari; spec says it can be up to 32768

• Component: Web Audio
• Status: RESOLVED FIXED

[Noah Chase]

Summary: the Web Audio spec says that an AnalyzerNode's `fftSize` "must be a power of two in the range 32 to 32768, otherwise an IndexSizeError exception must be thrown." – but in Safari, the `IndexSizeError` exception is thrown for values over 2048 (e.g. the next reasonable value, which is 4096).

Steps to Reproduce:

Try to assign your AnalyserNode's fftSize to 4096 

Expected Results:

Assignment should work

Actual Results:

`IndexSizeError` is thrown

Version/Build:

13604.3.5 and 13605.1.13.2

[Noah Chase]

Created attachment 327702 [details]
Patch

[Alex Christensen]

Could you include a link to the relevant spec?
Are there tests that check the actual output of these larger FFTs?
How do other browsers behave?  Do they follow the spec?

[Noah Chase]

1. Link to the place in the spec where this is described: https://www.w3.org/TR/webaudio/#widl-AnalyserNode-fftSize
2. I only found tests that either reject an fftSize (if it is out of range or something other than a power of two) or allow it – those tests have been updated here.
3. Other browsers do indeed behave and follow the spec (I have tested Firefox and Chrome, but nothing else).

[WebKit Commit Bot]

Comment on attachment 327702 [details]
Patch

Clearing flags on attachment: 327702

Committed r225226: <https://trac.webkit.org/changeset/225226>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/35726784>