[Discuss-gnuradio] Re: FM data available

[Stephane Fillod]

On Tue, Feb 11, 2003, Eric Blossom wrote:
[..] 
> I've made available 5 seconds of off-the-air broadcast FM data.
> Carriers for 4 stations can be clearly seen in the FFT.
> There's a classical station at 5.75 MHz.
> 
> The data is 16-bit, little endian, 20MS/s

Thank you very much Eric for the data file. It works fine!
I'm able to hear WFM using grig and changing frequencies through the GUI.

By the way, I have only 256MB of RAM, and my harddrive is not fast
enough to process data direct-from-disk. So I had to split the file in
100MB chunk.
Sadly enough, my Duron 1GHz is a bit slow too on data crunching, especially
using generic code for FIR filters. So I wrote fir_SCC optimization (for
GrFreqXlatingFIRfilter) using 3DNow!Ext, and it improves a bit:

(address@hidden:examples)$ ./benchmark_dotprod_SCC
   generic: taps:  256  input: 4e+07 cpu: 107.360  taps/sec:  9.538e+07
 3DNow!Ext: taps:  256  input: 4e+07  cpu: 29.710  taps/sec:  3.447e+08

I'll submit a patch when I have regular 3DNow! and SSE done.
For GrRealFIRfilter, what to you think is best? optimize fir_FSF or use
fir_FFF with convert_FS ?


I have another request for data file.
Is it possible for you to provide me a data file (16-bit, 20MS/s, size<100Mo),
containing Narrow FM, USB, and AM. Something like a Ham portion plus
air-band for the AM would be fine. In need to have data for *each* of
these modes to be able to test all the demodulators.

Cheers,
Stephane