[vorbis-dev] Fixed vs. Floating Point primer. was: Implementing Vorbis in hardware

[Steve Underwood]

"Borgerding, Mark A." wrote:
> [...] 
> So I guess my point is this:  If we just want to say that Vorbis is
> available for a DSP chip, then start with a floating point platform (I've
> heard good things about ADI's Sharcs).  But if we want to make it most
> attractive for portable player companies, then a fixed-point DSP algorithm
> will probably be better received.

I think that is a really bad idea. With many very cheap MP3 players
already in the market, the only thing anyone would be interested in is a
competitively low cost Vorbis platform. Put Vorbis on any floating point
DSP, and people will say its resource hungry. It would then be very hard
to dispell that impression.

It can be a Royal PITA programming fixed point DSPs (I've used many),
but they are they only kind of DSP acceptable for consumer products, and
the only ones low enough in power consumption for a portable player. The
MP3 people already had mature implementations on energy efficient fixed
point DSP architectures when the first MP3 players appeared - they had
been working on them for ages for the MPEG video player field. That is
what Vorbis needs to catch up on now. Monty said many MP3 players are
currently using StringARM. That would be the easiest route to port
Vorbis to a portable platform, as you can get a workable solution with a
few tweaks and a recompile. Since it avoids the need for a separate
management/control processor, StrongARM may be the most cost effective
platform overall.

Regards,
Steve

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