diff src/matlab/chromsynth.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/chromsynth.m	Sun Jun 18 06:26:13 2017 -0400
@@ -0,0 +1,75 @@
+function [x,CF,CM] = chromsynth(F,bp,sr)
+% [x,CF,CM] = chromsynth(F,bp,sr)
+%   Resynthesize a chroma feature vector to audio
+%   F is 12 rows x some number of columns, one per beat
+%   bp is the period of one beat in sec (or a vector of beat times)
+%   sr is the sampling rate of the output waveform
+%   x is returned as a 12 semitone-spaced sines modulated by F
+%   CF,CM return actual sinusoid matrices passed to synthtrax
+%   Actual Shepard tones now implemented! 2007-04-19
+% 2006-07-14 [e-mail]
+
+if nargin < 2; bp = 0.5; end % 120 bpm
+if nargin < 3; sr = 22050; end
+
+[nchr,nbts] = size(F);
+
+% resynth
+if length(bp) == 1
+  bups = 8; % upsampling factor
+  framerate = bups/bp;
+  ncols = nbts*bups;
+  CMbu = zeros(nchr, ncols);
+  for i = 1:bups
+    CMbu = CMbu + upsample(F', bups, i-1)';
+  end
+else
+  % vector of beat times - quantize
+  framerate = 50; % frames per sec
+  nbeats = length(bp);
+  lastbeat = bp(nbeats) + (bp(nbeats) - bp(nbeats-1));
+  ncols = round(lastbeat * framerate);
+  CMbu = zeros(nchr, ncols);
+  xF = [zeros(12,1),F];
+  for i = 1:ncols
+    CMbu(:,i) = xF(:,max(find(i/framerate >= [0,bp])));
+  end
+end
+  
+%CFbu = repmat(440*2.^([0:(nchr-1)]'/nchr),1,ncols);
+%x = synthtrax(CFbu,CMbu,sr,round(sr/framerate));
+octs = 7;
+basefrq = 27.5;  % A1; +6 octaves = 3520
+CFbu = repmat(basefrq*2.^([0:(nchr-1)]'/nchr),1,ncols);
+CF = [];
+CM = [];
+% what bin is the center freq?
+f_ctr = 440;
+f_sd = 0.5;
+f_bins = basefrq*2.^([0:(nchr*octs - 1)]/nchr);
+f_dist = log(f_bins/f_ctr)/log(2)/f_sd;  
+% actually just = ([0:(nchr*octs - 1)]/nchr-log2(f_ctr/basefrq))/f_sd
+% Gaussian weighting centered of f_ctr, with f_sd
+f_wts = exp(-0.5*f_dist.^2);
+for oct = 1:octs
+  CF = [CF;(2^oct)*CFbu];
+  % pick out particular weights
+  CM = [CM;diag(f_wts((oct-1)*nchr+[1:nchr]))*CMbu];
+end
+% Remove sines above nyquist
+CFok = (CF(:,1) < sr/2);
+CF = CF(CFok,:);
+CM = CM(CFok,:);
+% Synth the sines
+x = synthtrax(CF,CM,sr,round(sr/framerate));
+
+% Playing synth along with audio:
+%>> rdc = chromsynth(Dy.F(:,160+[1:300]),Dy.bts(160+[1:300]) - Dy.bts(160),sr);
+%>> Dy.bts(161)*sr              
+%ans =
+%      279104
+%>> size(rdc)
+%ans =
+%           1      498401
+%>> ddd = db(279104+[1:498401]);
+%>> soundsc([ddd,rdc'/40],sr)