Re: [web-audio-api testing] Best way of testing an AudioNode output

Hi Amitay,

Thanks for taking a look at this. The approach we decided was to use
OfflineAudioContext, but to generate the expected output in pure
javascript where possible (for example, the expected output of the
OscillatorNode set to generate a sine wave would be compared to that
generated using Math.sin()) rather than using wav files to contain the
expected output.

Using OfflineAudioContext allows the tests to run faster than real time.

MediaElementSourceNode might be a bit tricky to test. The Web platform
tests have a mechanism for serving up test files, so perhaps we could
use a file delivered through an <audio> tag, compared to the same file
loaded into an audiobuffer?

Any questions, please ask away - or if you'd like to work on some code
together, submit a pull request to web platform tests and I can take a



On 26 October 2013 21:40, Amitay Dobo <> wrote:
> Hi,
> I'm trying to come up with a test for expected
> MediaElementAudioSourceNode  output behavior.
> However, I'm not sure what is the preferred way to test it as a unit,
> without testing other components as a side effect.
> Some approaches:
> 1) Using OfflineAudioContext as in the current Web Platform Audio test
> (
> 2) Using an Analyser node (preliminary test at
> 3) Using a ScriptProcessor node (preliminary test at
> ).
> I want to to limit as much as possible depenencies in other components.
> Would be happy to hear your thoughts and suggestions.
> Cheers,
> Amitay
> P.S. This is a test I find important right now, since In firefox
> nightly and older webkit browsers (i.e. Safari 6) connecting a
> MediaElement source to either ProcessorNode or AnalyserNode does not
> yield expected results.

Received on Monday, 28 October 2013 08:53:56 UTC