NVDSP icon indicating copy to clipboard operation
NVDSP copied to clipboard

BandPass filter help

Open ksuhr1 opened this issue 4 years ago • 1 comments

Hey there! I'm trying to use your bandpass filter to filter an array of values (I'm trying to do heart beat detection). I'm new to signal processing and I was wondering if you could explain how to get the coefficients within your code. I see they are being called in this example on stackoverflow: https://stackoverflow.com/questions/10604690/noise-distortion-after-doing-filters-with-vdsp-deq22-biquad-iir-filter/10608609#10608609. I'm trying to create a bandpass filter between 0.667 Hz and 4.167 Hz. I have a sample rate of 30 frames per second. If you have any tips or can confirm if I could use your framework to do this that would be helpful! Thank you!

// import Novocaine.h and NVDSP.h #import "NVDSP/Filter/NVBandpassFilter.h" NVBandpassFilter *BPF = [[NVBandpassFilter alloc] initWithSamplingRate:audioManager.samplingRate]; BPF.centerFrequency = 2500.0f; BPF.Q = 0.9f; [BPF filterData:data numFrames:numFrames numChannels:numChannels];

ksuhr1 avatar Jul 28 '20 02:07 ksuhr1