annotate mirex2012-matlab/computeCQT.m @ 116:91bb029a847a timing

Reorder the calculations to match the series of vector operations in the most recent bqvec code, just in case it's the order of vector calculations that is saving the time rather than the avoidance of std::vector

function [intCQT] = computeCQT(filename)
% Settings for computing CQT for music signals (by E. Benetos)

% Load .wav file
[x fs bits] = wavread(filename);
if (size(x,2) == 2) y = mean(x')'; clear('x'); else y=x; clear('x'); end;
if (fs ~= 44100) y = resample(y,44100,fs); end;
y = 0.5*y/max(y);
fs = 44100;


% Compute CQT
Xcqt = cqt(y,27.5,fs/3,60,fs,'q',0.80,'atomHopFactor',0.3,'thresh',0.0005,'win','hann');
%Xcqt = cqt(y,27.5,fs/3,120,fs,'q',0.35,'atomHopFactor',0.3,'thresh',0.0005,'win','hann'); % old resolution
absCQT = getCQT(Xcqt,'all','all');

% Crop CQT to useful time regions
emptyHops = Xcqt.intParams.firstcenter/Xcqt.intParams.atomHOP;
maxDrop = emptyHops*2^(Xcqt.octaveNr-1)-emptyHops;
droppedSamples = (maxDrop-1)*Xcqt.intParams.atomHOP + Xcqt.intParams.firstcenter;
outputTimeVec = (1:size(absCQT,2))*Xcqt.intParams.atomHOP-Xcqt.intParams.preZeros+droppedSamples;

lowerLim = find(outputTimeVec>0,1);
upperLim = find(outputTimeVec>length(y),1)-1;

%intCQT = absCQT(112:1200,lowerLim:upperLim); % old resolution
intCQT = absCQT(56:600,lowerLim:upperLim);


%figure; imagesc(imrotate(abs(intCQT),90));