[speex-dev] Re: Fixed-point Speex

B. Mitchell Loebel multinode at earthlink.net
Fri Apr 4 12:55:56 PST 2003

Hello Jean-Marc, et al:

I'm sorry to have been unclear. I do prefer two separate code bases.

How do you suggest that we get a mailing list together? Please include me.

I'm still suggesting another addition to the agenda ... again looking 
to acceptance by a using community. I'd like to see us target 
specific processor/s with the fixed point code we are creating ... 
inlining assembly functions, using registers where possible, taking 
care with pipelines, unrolling loops, etc. At the moment most of the 
proprietary codecs with which I am familiar are targeted to the T.I. 
DSP's. That means that Analog Devices and ARM are "one down" 
competitively ... they desperately need a codec that's been optimized 
for their ucontrollers. I'll bet we could get some early support ... 
hardware, software, and maybe even $$ from them and I'd be willing to 
make the approach (can you say Blackfin from Analog Devices?). I 
think that mine is a particularly interesting proposition because the 
Embedded Systems Conference is coming to Silicon Valley in a few 
weeks ... the decision makers will be on the floor and I am located 
in San Jose, CA!

Optimizing may be only a matter of re-writing a handful of functions, 
but that's not trivial if one has tight $$ constraints (as I do) with 
an embedded systems project. Furthermore, a 'real world' code base 
might require some quality compromises in order to meet $$ and bit 
rate constraints. What are those compromises and how do they map onto 
the code?

>I say let's start by writing generic C code and then start optimizing.
>What's important is to get good quality code that's still useful as a
>"reference fixed-point implementation". After that, optimizing is only a
>matter of re-writing a handful of functions: various filters, a VQ
>search and inner product. That's already what I did with the SSE
>optimizations: they're all contained in two small files (filters_sse.h
>and ltp_sse.h).

Thank you. I've copied Greg on this email.

Greg: Could you be available?

>You might want to ask Greg Herlein (gherlein at herlein.com), the author of
>the Speex RTP profile. He lives in San Francisco.

>> One final point ... I direct The Tech Startup Connection (please visit
>> www.TechStartupConnection.org). We hold monthly meetings in Silicon
>> Valley to help startups get off the ground. If somebody from the speex
>> community could/would agree to make a presentation to our May 12th
>> evening meeting at Fenwick and West in Mountain View, I think that we
>> could pick up a very competent group of volunteers. Any takers?

<p><p><p>B. Mitchell Loebel

<p>CEO, Chief Technical Officer
Multinode Microsystems Corporation			408 264-2068 office
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