Eric Blossom wrote: > On Mon, Apr 16, 2007 at 08:24:46PM +0200, Martin Dvh wrote: > >>Hew How Chee wrote: >> >>>Hi Martin, >>> >>> >>> >>>>I have been using the code with an external tuner >>>>frontend and did some experiments with fm-receiving, >>>>which just works fine. >>> >>> >>>Interested to know what is the speed of the CPU that >>>you are using and how many percent of the CPU power >>>has been used up. > > >>I have a dual-core AMD athlon 64 X2 3800+ (2x2 Ghz) >>I think only one CPU is used by gnuradio. >>I haven't looked at the processor percentages in detail. > > > Excellent! Glad to hear you got a new machine ;) Yes, I am very happy with it. But as allways, within no time I am working on the limits of the new machine. I am still considering a Cell-based machine (PS3). Did you even got around to playing with that? > > > Are you using gr.fir_filter_ccf or gr.fft_filter_ccc? I am using gr.freq_xlating_fir_filter_fcf which uses: gr_fir_fcc
The cx2388x TV capture card is a real source so I don't use filters with complex input like ccf or ccc. > > (There's no fft_filter_ccf since the cost for complex taps is the same > as float taps in the FFT version. _ccc will accept real taps in the > argument list and convert them to complex automagically.) But I can't connect a float input stream to gr_fft_filter_ccc directly. I would have to put a float2complex block in front. Even better a unsigned_char to complex or short to complex, (also not yet there yet, I know) I would also have to do the freq translation manually in front by manually multiplying with a sinus sig_source with the right freq. If might be more efficient to make a gr.freq_xlating_fir_filter_fft_fcf which does all in one step But I don't know if an FFT version will also be much more efficient very high decimation factors. (I use a decimation of 100). The number of taps might run the cpu out-of its cache, which is something fftw doesn't like. On the other hand log(N) is much better then N with high N. I would have to try and do some profiling. But for now just first get the tv-card tuner working. No premature optimization. (I learned this from you) Greetings, Martin > > Eric > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
