[whatwg] need a way to set output format from StreamRecorder

Kevin Marks kevinmarks at gmail.com
Sat Nov 27 11:51:22 PST 2010


For Audio at least, supporting uncompressed should be possible and
uncontroversial, as there are clearly no patent issues here. Anyone serious
about recording and processing audio would not consider recording compressed
audio nowadays. T

There are several widely used raw audio formats (.au, WAV, AIFF, AVI) that
can wrap into a filestream, and there are of course the issues of sample
rate, channel count and bit resolution, but compared to codec issues these
are relatively straightforward from an engineering point of view, and not
tied up with licensing issues.

Raw video is more of a problem at present, given common bandwidth
constraints, but if we are interested in providing for image manipulation
APIs, having pixel formats that map to video better than RGBA may be needed.
The enumeration at
http://developer.apple.com/quicktime/icefloe/dispatch020.html
may be helpful here.

On Fri, Nov 26, 2010 at 11:10 AM, Nils Dagsson Moskopp <
nils-dagsson-moskopp at dieweltistgarnichtso.net> wrote:

> Silvia Pfeiffer <silviapfeiffer1 at gmail.com> schrieb am Thu, 25 Nov 2010
> 20:01:37 +1100:
>
> > Also, implementing WebM or Ogg Theora encoding is just as royalty-free
> > as decoding them, so Mozilla, Opera and Google wouldn't need to worry
> > there.
>
> Slightly offtopic: Anyone considering the low-bandwith audio use case?
> Surely, speex might be useful here — even a throttled UMTS connection
> suffices for VoIP.
>
> > So, the browsers would implement support for those codecs for which
> > they already implement decoding support - maybe with the exception of
> > Chrome which decode MPEG-4, but may not want to encode it, since it
> > might mean extra royalties.
>
> And probably less WebM content, too boot. Decoding, but not encoding
> MPEG formats could certainly fit into a royalty-free formats agenda,
> depending on the level of aggressiveness Google is wishing to take.
>
> > It would be nice if we could all, say, encode WebM, but I don't see
> > that happening.
>
> I see what you did there.
>
>
> Greetings,
> --
> Nils Dagsson Moskopp // erlehmann
> <http://dieweltistgarnichtso.net>
>
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