diff src/matlab/fft2chromamx.m @ 0:c52bc3e8d3ad tip

user: boblsturm
branch 'default'
added README.md
added assets/.DS_Store
added assets/playButton.jpg
added assets/stopButton.png
added assets/swapButton.jpg
added data/.DS_Store
added data/fiveoctaves.mp3
added data/glock2.wav
added data/sinScale.mp3
added data/speech_female.mp3
added data/sweep.wav
added nimfks.m.lnk
added src/.DS_Store
added src/matlab/.DS_Store
added src/matlab/AnalysisCache.m
added src/matlab/CSS.m
added src/matlab/DataHash.m
added src/matlab/ExistsInCache.m
added src/matlab/KLDivCost.m
added src/matlab/LoadFromCache.m
added src/matlab/SA_B_NMF.m
added src/matlab/SaveInCache.m
added src/matlab/Sound.m
added src/matlab/SynthesisCache.m
added src/matlab/chromagram_E.m
added src/matlab/chromagram_IF.m
added src/matlab/chromagram_P.m
added src/matlab/chromsynth.m
added src/matlab/computeSTFTFeat.m
added src/matlab/controller.m
added src/matlab/decibelSliderReleaseCallback.m
added src/matlab/drawClickCallBack.m
added src/matlab/fft2chromamx.m
added src/matlab/hz2octs.m
added src/matlab/ifgram.m
added src/matlab/ifptrack.m
added src/matlab/istft.m
added src/matlab/nimfks.fig
added src/matlab/nimfks.m
added src/matlab/nmfFn.m
added src/matlab/nmf_beta.m
added src/matlab/nmf_divergence.m
added src/matlab/nmf_euclidean.m
added src/matlab/prune_corpus.m
added src/matlab/rot_kernel.m
added src/matlab/templateAdditionResynth.m
added src/matlab/templateDelCb.m
added src/matlab/templateScrollCb.m

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/matlab/fft2chromamx.m	Sun Jun 18 06:26:13 2017 -0400
@@ -0,0 +1,64 @@
+function wts = fft2chromamx(nfft,nbins,sr,A440,ctroct,octwidth)
+% wts = fft2chromamx(nfft,nbins,sr,A440,ctroct,octwidth)
+%     Create a wts matrix to convert FFT to Chroma
+%     A440 is optional ref frq for A
+%     ctroct, octwidth specify a dominance window - Gaussian
+%     weighting centered on ctroct (in octs, re A0 = 27.5Hz) and 
+%     with a gaussian half-width of octwidth.  Defaults to
+%     halfwidth = inf i.e. flat.
+%     2006-06-29 [e-mail]
+
+if nargin < 2;   nbins = 12;  end
+if nargin < 3;   sr = 22050; end
+if nargin < 4;   A440 = 440; end
+if nargin < 5;   ctroct = 5; end
+if nargin < 6;   octwidth = 0; end
+
+wts = zeros(nbins, nfft);
+
+fftfrqbins = nbins*hz2octs([1:(nfft-1)]/nfft*sr,A440);
+
+% make up a value for the 0 Hz bin = 1.5 octaves below bin 1
+% (so chroma is 50% rotated from bin 1, and bin width is broad)
+fftfrqbins = [fftfrqbins(1)-1.5*nbins,fftfrqbins];
+
+binwidthbins = [max(1, fftfrqbins(2:nfft) - fftfrqbins(1:(nfft-1))), 1];
+
+D = repmat(fftfrqbins,nbins,1) - repmat([0:(nbins-1)]',1,nfft);
+
+nbins2 = round(nbins/2);
+
+% Project into range -nbins/2 .. nbins/2
+% add on fixed offset of 10*nbins to ensure all values passed to rem are +ve
+D = rem(D + nbins2 + 10*nbins, nbins) - nbins2;
+
+% Gaussian bumps - 2*D to make them narrower
+wts = exp(-0.5*(2*D./repmat(binwidthbins,nbins,1)).^2);
+
+% normalize each column
+wts = wts./repmat(sqrt(sum(wts.^2)),nbins,1);
+
+% remove aliasing columns
+wts(:,[(nfft/2+2):nfft]) = 0;
+
+% Maybe apply scaling for fft bins
+if octwidth > 0
+  wts = wts.*repmat(exp(-0.5*(((fftfrqbins/nbins - ctroct)/octwidth).^2)), nbins, 1);
+end
+
+%wts = binwidthbins;
+%wts = fftfrqbins;
+
+function octs = hz2octs(freq, A440)
+% octs = hz2octs(freq, A440)
+% Convert a frequency in Hz into a real number counting 
+% the octaves above A0. So hz2octs(440) = 4.0
+% Optional A440 specifies the Hz to be treated as middle A (default 440).
+% 2006-06-29 [e-mail] for fft2chromamx
+
+%if nargin < 2;   A440 = 440; end
+
+% A4 = A440 = 440 Hz, so A0 = 440/16 Hz
+octs = log(freq./(A440/16))./log(2);
+
+