Re: [Agenda] W3C Audio WG Teleconference, 13th June 2012

Hi Philip, all,


On 13 Jun 2012, at 10:21, Philip Jägenstedt wrote:
>> 1) Testing
>> Let's start the conversation about the testing effort for the Web Audio API and MIDI API. There are already several initiatives and tests produced, but no coordinated effort yet. Expected outcome: rough agreement on type of test framework, nominate test lead(s).
> 
> I think that we should use the W3C test harness, we use this at Opera for all of our new tests and I have no complaints about it:
> 
> http://w3c-test.org/resources/testharness.js
> 
> As for methodology, tests fall roughly into two categories:
> 
> 1. Interface tests. This is things like asserting that "new AudioContext()" returns an object of the correct type, that it has the methods it should have, that calling ctx.createMediaElementSource() with no argument throws the appropriate exception, and so on. These tests are easy to write and to pass.
> 
> 2. Semantic tests, to verify that the audio graph actually does the correct thing. In general, I think we should try to implement all native nodes in JavaScript and verify that the output is the same within some margin of error, a graph like:

I agree with the approach, thanks for starting the discussion. The trick for us may reside in the "margin of error". Given that our API won't specify exactly all the algorithms used in e.g filters and the convolution engine, the output of a given graph will not be exactly the same from one implementation to another, but should "sound roughly the same". Defining that "roughly" will be the key to the compliance statements in the spec, and consequently to the testing effort.

Olivier