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Subject: Re: WAV Codec for Archos

Re: WAV Codec for Archos

From: [IDC]Dragon <idc-dragon_at_gmx.de>
Date: 2006-01-24

Before the myths start outgrowing the facts:

The MAS is downloadable, but its internal memory is very small. The feature
was meant for voice codec download. Only very small codecs would fit, not
"any one you'd like". The PCM "codec" is of course the most trivial one,
just pumping data to/from the DAC/ADC. The MAS as a DSP is too esoteric,
undocumented and proprietary to reasonably start your own codec development.

Patching the PCM codec into Rockbox for Archos is not not a trivial task. If
done properly, it's an opportunity to renovate the playback+recording code,
like keeping the bitswap away from the big buffer, a different concept for
metadata of buffered files, a frame walker for mp3, trick modes, etc. I'd
liked to have done that, but other priorities got in the way.

For full quality wav pumping, our poor CPU would be pretty busy with
bitswapping. Don't let your expectations fly too high about running codecs
on it, too. The disk will be busy, too, having 8 MB helps.
I'm not worried about audio quality. When using S/PDIF, it's 1:1, as much as
you can get.

Jörg

-- 
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Received on Tue Jan 24 22:41:50 2006

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