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Web Audio API spec review

From: Philip Jägenstedt <philipj@opera.com>
Date: Tue, 15 May 2012 13:45:35 +0200
To: public-audio@w3.org
Message-ID: <op.wecll9lmsr6mfa@kirk>
Marcus and I have begun spec review of the Web Audio API and MediaStream  
Processing with the expectation to start implementing something in the not  
too distant future.

We intend to create individual issues for the many different problems we  
have identified, this mail is a heads-up and a high-level commentary on  
the status of the Web Audio API.

The executive summary is that the Web Audio API is largely underspecified  
and that we could not even begin to implement it based on the existing  
spec without reverse-engineering Chris Rogers' implementation. The spec  
consists mostly of interface documentation suitable for Web authors and is  
very sparse on normative requirements for user agents, which makes it  
impossible to write a test suite for.

There are a few aspects that make the Web Audio API fit poorly with the  
rest of the Web platform. For example, the integration with  
HTMLMediaElement is one-way; the audio stream of a <video> can be passed  
into AudioContext but the result cannot leave AudioContext or play in sync  
with the video channel. That an AudioContext cannot be paused means that  
certain filtering effects on any stallable input (<audio>, MediaStream)  
cannot be implemented, echo or reverb being the most obvious examples.

We will begin creating detailed issues shortly and will send out a summary  
when done. Our hope is that this email and the individual issues do not  
come across as needlessly negative, the shared purpose of the members of  
this WG is the same after all -- to produce a high-quality spec and  
interoperable implementations to match.

Philip Jägenstedt
Core Developer
Opera Software
Received on Tuesday, 15 May 2012 11:46:00 UTC

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