On Mon, 10 Aug 2015 at 13:14 Marcus Müller <marcus.muel...@ettus.com> wrote:
> Hi Tom, > > I just had to look this up. If you're in GRC, you have "rationale > resampler" and "rational resampler base"; they do basically the same, but > if you use the one without "base", and don't specify the taps, GNU Radio > just automatically designs a filter that avoids all aliasing and imaging, > which is done with a python wrapper around the C++ > rational_resampler_base_xxx's make function[1]. That's pretty handy in most > use cases, but not too much if you want your own filter for some reason. > > If you're using the "base" variant, you *must* specify the taps yourself, > because you directly invoke the C++ block's maker. If you go ahead and just > use "[1.0]" as taps, you get the aliased results from my pictures. > > So if you happen to *want *to specify the taps, because you can integrate > the functionality of a downstream filter into the resampler to save CPU > cycles, it doesn't make a difference which block you use. > Ah, I see. Many thanks for taking the time to explain this. Where did you look to find out that 'rational resampler' block does an automatic filter design for you? Regards, Tom
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
