[Speex-dev] Stereo speex on Blackfin

[Robin Getz]

On Tue 17 Apr 2007 02:15, Justin Clacherty pondered:
> Hi,
>
> I'm trying to encode a stereo speex file on the blackfin without much
> luck.  This is a standalone application with no OS using the speex
> library provided in the blackfin multimedia sdk.  I believe this library
> was ported to run using Visual DSP++ by Jean-Marc (may be wrong).

Glad things are working - but to provide some clarifications - the Speex that 
is included in the Blackfin multimedia SDK is an __old__ (about ~2-3 years 
ago) version of speex that someone at ADI ported (not Jean-Marc - so don't 
blame him for anything). I think it was done the same time this was written 
(late 2004/early 2005):

http://www.analog.com/UploadedFiles/Technical_Articles/296785076open_source.pdf

So you might have some luck contacting those authors.

Speex has gone through alot of improvements since then, and I don't think the 
speex you have produces a binary compatible bitstream with the current 
trunk/release (if you are not looking for compatibility with other systems, 
it doesn't matter).

The current speex trunk/release does include a Blackfin version, which can be 
used in an non-OS environment, but must be compiled to gcc, not ADI's VDSP++, 
since it uses some pretty aggressive assembly optimisations, which VDSP++ can 
not digest (last time someone tried).

If memory serves (which has been a little faulty recently), the VDSP++ 
implementation was ~30-40 MIPS range, and speex trunk is less than 1/2 of 
this with gcc.

-Robin