[whatwg] default audio upload format (was Fwd: The Media Capture API Working Draft)

Roger Hågensen rescator at emsai.net
Fri Sep 3 14:08:49 PDT 2010

  On 2010-09-01 21:34, David Singer wrote:
> seems like a comma-separated list is the right way to go, and that audio/* should mean what it says -- any kind of audio (whether that is useful or not remains to be seen).
> I would suggest that this is likely to be used for short captures, and that uncompressed (such as a WAV file or AVI with PCM or u-law audio) should be the recommended format.
> If your usage is for longer captures or more specific situations, then indicate a suitable codec.
> Shouldn't there be statements about channels (mono, stereo, more), sampling rate (8 kHz speech, 16 kHz wideband speech, 44.1 CD-quality, 96 kHz bat-quality) and so on?

Hmm! Channels, bits, frequency should be optional in my opinion, (and 
with a recommendation for a default, stereo 16bit 44.1KHz which is the 
legacy standard for audio in most formats I guess, or maybe 48KHz as 
most soundcards seem to be these days?)
In most cases a service will either A. use it as it's received (since 
most computer systems can play back pretty much anything), or B. it's 
transcoded/converted into one or more formats by the service. (like 
Youtube does etc.)
In other words I am assuming that if the server accept for example the 
WAV format then it actually fully support the WAV format (at least the 
PCM audio part). Ditto with MP3, AAC, Ogg, FLAC, Speex etc.

So any quality, channels, bits, frequency specified in the accept would 
just be what the server prefers (suggested default, or for best 
quality/best effort scenario), but the full format should be supported 
and accepted if asked for.
Now whether the service takes advantage of surround rear recording is up 
to the service, if it simply discards that, takes the front channels and 
mix them to mono then that is up to the service and the user to 
decide/negotiate about rather than the browser.

Roger "Rescator" Hågensen.
Freelancer - http://EmSai.net/

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