Re: [mediacapture-main] Specification to capture unmodified audio

@klausj , @burnburn ,

With respect to the question of whether hardware prefilters audio with no way to disable the filter(s) AND therefore this processing can not be disabled by webRTC (to get raw audio), my experience has been that raw audio is always obtainable natively and therefore there is no reason it wouldn't also be available to the browser (which at its core is native). Does anyone know that there exists hardware that absolutely provide no raw audio mode (and in what platform)? Every iphone, android phone, chromebook, windows pc and macbook I have at my disposal seems to have raw audio sampling (via native code or by setting webRTC audio: constraints:false). Albeit I did have to manually configure a chromebook to raw audio sampling which is really unacceptable that it could not be done via the browser with webRTC.

However, my bigger concern is that we feel the need to add a constraint at all for raw audio. Shouldn't it simply be raw by default? Isn't a constraint by definition constraining something and therefore raw audio is by definition unconstrained? Someone help me understand this and the need for any constraint definition for raw audio. Even if the hardware or codec is by default filtering the audio, the browsers mediacapture audio: code should, in my opinion, start with raw audio and add filters as requested. Am I wrong in assuming that the browsers are running natively (even if on top of IOS Safari).

I have read that certain codecs only have sample rates in multiples of 24000 hz. So my other concern is that arguably the most common audio sample rate of 44.1KHz is not universally available to webRTC development (made even worse by the fact that sample rate is selectable natively and it is available natively on IOS and Android anyway). I think, should 44.1KHz not be available via the hardware and a developer requests it, rather than deny the request, the webRTC handler in the browser should resample 48KHz down to 44.1 behind the scenes from the developer and this should apply to any analyser nodes attached.

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Received on Friday, 5 January 2018 01:41:40 UTC