annotate constant-q-cpp/misc/yeti/icqt.yeti @ 372:af71cbdab621 tip

Update bqvec code

/*
    Constant-Q library
    Copyright (c) 2013-2014 Queen Mary, University of London

    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation
    files (the "Software"), to deal in the Software without
    restriction, including without limitation the rights to use, copy,
    modify, merge, publish, distribute, sublicense, and/or sell copies
    of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    Except as contained in this notice, the names of the Centre for
    Digital Music; Queen Mary, University of London; and Chris Cannam
    shall not be used in advertising or otherwise to promote the sale,
    use or other dealings in this Software without prior written
    authorization.
*/

module icqt;

cqt = load cqt;
cm = load may.matrix.complex;
framer = load may.stream.framer;
win = load may.signal.window;
mm = load may.mathmisc;
vec = load may.vector;
resamp = load may.stream.resample;
manip = load may.stream.manipulate;
mat = load may.matrix;

icqt cq =
   (kdata = cq.kernel;

    // kdata.kernel is the kernel matrix for a single octave. It has
    // width kdata.fftSize and height kdata.binsPerOctave *
    // kdata.atomsPerFrame.
    //
    // kdata.fftHop is the overlap between kernel matrices in a single
    // octave.
    // 
    // cq.sampleRate is the output stream sample rate and cq.octaves
    // the number of octaves.
    //
    // cq.cqComplex is the list of complex matrices containing the CQ
    // output. Each has width kdata.atomsPerFrame * 2^(cq.octaves-1)
    // and height kdata.binsPerOctave * cq.octaves.

    bpo = kdata.binsPerOctave;
    atomsPerFrame = kdata.atomsPerFrame;
    octaves = cq.octaves;

    // transform a single block, all octaves tall, into an array
    // (indexed by octave) of lists of individual columns (valid
    // values for that octave only)
    decomposeOctaves mat = array
       (map do oct:
            inverted = cm.fromRows (reverse (cm.asRows mat));
            octMat = cm.rowSlice inverted (bpo * oct) (bpo * (oct + 1));
            gap = (mm.pow 2 oct) - 1;
            pickFrom cols =
                case cols of
                c::cs: c::(pickFrom (drop gap cs));
                _: [];
                esac;
            pickFrom (cm.asColumns octMat);
        done [0..octaves-1]);

    // transform a list of the arrays produced by decomposeOctaves
    // into a single array (indexed by octave) of lists of the
    // individual columns
    flattenOctaves decomposed =
       (flattenAux acc decomposed = 
            case decomposed of
            chunk::rest:
                flattenAux 
                   (array
                       (map do oct:
                            acc[oct] ++ chunk[oct]
                            done [0..octaves-1]))
                    rest;
            _: acc;
            esac;
        flattenAux (array (map \[] [0..octaves-1])) decomposed);

    // given a list of columns, deinterleave and pile up each sequence
    // of atomsPerFrame columns into a single tall column and return
    // the resulting list of tall columns
    pile cols =
       (pileAux acc cols =
            if (length cols) >= atomsPerFrame then
                atoms = take atomsPerFrame cols;
                juggled = concat (reverse (cm.asRows (cm.fromColumns atoms)));
                pileAux (juggled :: acc) (drop atomsPerFrame cols);
            else
                reverse acc
            fi;
        pileAux [] cols);

    octaveColumnLists = 
        map pile (list (flattenOctaves (map decomposeOctaves cq.cqComplex)));

    for octaveColumnLists do l: println "octave column list length: \(length l)" done;

    kernel = cm.transposed kdata.kernel; // right way around for the multiply
    
    spectra = 
        map do l:
            map do col:
                res = cm.transposed (cm.product kernel (cm.newComplexColumnVector col));
                cm.columnSlice res 0 (kdata.fftSize / 2 + 1)
            done l;
        done octaveColumnLists;

    eprintln "calculated spectra, now to ifft, overlap-add...";

    rates = map do oct: cq.sampleRate / (mm.pow 2 oct) done [0..cq.octaves-1];
    
    resynthesised =
        map2 do frames rate:
            framer.complexStreamed rate kdata.fftSize
                [ FrequencyDomain true, Window win.boxcar, Hop kdata.fftHop ]
                frames;
        done spectra rates;

   eprintln "have streams:";
   for resynthesised eprintln;

   resampled = map (resamp.resampledTo cq.sampleRate) resynthesised;

   manip.sum resampled;
);

{icqt}