Re: [Discuss-gnuradio] SDTV decoding

[Eric Blossom]

On Thu, Nov 25, 2004 at 03:09:50PM -0600, David Carr wrote:
> What are the current speed numbers (with modern hardware) for ATSC 
> decoding?  

Haven't checked in a while, but we were at about 30x real time using a
Athlon XP1800.  No performance tuning has been done at all, so there's
probably some low hanging fruit.  That was also with a naive 256 tap
equalizer.  With some cleverness, we can probably cut that down to
something more like 25 - 50 taps.
        
> As a sort of side note I recently aquired access to a 32 cpu 
> Athlon MP1800 cluster.  If someone were interested in making it easier 
> to parallelize the decoding we could probably do an real time HDTV 
> experiment.

Cool.  Can you say some more about this cluster?  
Is it a shared memory NUMA machine?
Is this something more like a blade server?

If we split the ATSC decoding across machines, the data rate into and
out of the machines is pretty high.  In much of the pipeline we're
dealing with floats at 20M samples / second --> 80 MB/sec.  This would
take a bit of finesse, but isn't a show stopper.

> Just something to think about,
> -David Carr

Eric