Resampling 250kHz signal to 192kHz

[tomb18]

Hi,
I am not an expert in DSP. I use libraries like this one. Unfortunately the library I use does not have a resample capability.
This is the first one I can understand. It looks like it would work perfect for my usage.
So my first question is that can the FIR filter handle 1025 taps?
Second, what would be the performance like with 16384 samples in on a continuous basis?
Thanks. Tom

[ar1st0crat]

Hi!
Sorry for the VERY late reply. Unfortunately I had absolutely no time for open source activity.

Anyway this lib couldn't really help solving your task, since its support of resampling is very basic so far. Resampling is quite difficult topic (at least for me) and deserves the separate library. There are some c++ examples AFAIK. 250/192 ratio requires more sophisticated algorithms than just simple interpolation/decimation provided by this lib.

UPD: as of Feb.2019 the bandlimited resampling became available:

var resampled = Operation.Resample(signal, (double)192 / 250)

As for filtering - recently I added the BlockConvolver class capable of OLA/OLS real-time processing. I think it will work well with 1025-size kernels and 16384-point chunks. It can be used like this:

FirFilter filter = new FirFilter(kernel);    // 1025-size kernel

var blockConvolver = OlsBlockConvolver.FromFilter(filter, 16384);

// processing loop:
// while new input sample is available
{
	var output = blockConvolver.Process(inputSample);
}

See also OnlineDemoForm code.