annotate src/CQSpectrogram.cpp @ 132:c188cade44f8

Tests (not quite correct yet)

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
/*
    Constant-Q library
    Copyright (c) 2013-2014 Queen Mary, University of London

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#include "CQSpectrogram.h"

#include <iostream>
#include <stdexcept>

using std::cerr;
using std::endl;

CQSpectrogram::CQSpectrogram(CQParameters params,
                             Interpolation interpolation) :
    m_cq(params),
    m_interpolation(interpolation)
{
}

CQSpectrogram::~CQSpectrogram()
{
}

CQSpectrogram::RealBlock
CQSpectrogram::process(const RealSequence &td)
{
    return postProcess(m_cq.process(td), false);
}

CQSpectrogram::RealBlock
CQSpectrogram::getRemainingOutput()
{
    return postProcess(m_cq.getRemainingOutput(), true);
}

CQSpectrogram::RealBlock
CQSpectrogram::postProcess(const ComplexBlock &cq, bool insist)
{
    int width = cq.size();

    // convert to magnitudes
    RealBlock spec;
    for (int i = 0; i < width; ++i) {
        int height = cq[i].size();
        RealColumn col(height, 0);
        for (int j = 0; j < height; ++j) {
            col[j] = abs(cq[i][j]);
        }
        spec.push_back(col);
    }

    if (m_interpolation == InterpolateZeros) {
        for (int i = 0; i < width; ++i) {
            int sh = spec[i].size();
            int fh = getTotalBins();
            for (int j = sh; j < fh; ++j) {
                spec[i].push_back(0);
            }
        }
	return spec;
    }

    for (int i = 0; i < width; ++i) {
	m_buffer.push_back(spec[i]);
    }
    
    if (m_interpolation == InterpolateHold) {
	return fetchHold(insist);
    } else {
	return fetchLinear(insist);
    }
}

CQSpectrogram::RealBlock
CQSpectrogram::fetchHold(bool)
{
    RealBlock out;
    
    int width = m_buffer.size();
    int height = getTotalBins();

    for (int i = 0; i < width; ++i) {
	
	RealColumn col = m_buffer[i];

	int thisHeight = col.size();
	int prevHeight = m_prevColumn.size();

	for (int j = thisHeight; j < height; ++j) {
	    if (j < prevHeight) {
		col.push_back(m_prevColumn[j]);
	    } else {
		col.push_back(0.0);
	    }
	}

	m_prevColumn = col;
	out.push_back(col);
    }

    m_buffer.clear();

    return out;
}

CQSpectrogram::RealBlock
CQSpectrogram::fetchLinear(bool insist)
{
    RealBlock out;

    //!!! This is surprisingly messy. I must be missing something.

    // We can only return any data when we have at least one column
    // that has the full height in the buffer, that is not the first
    // column.
    //
    // If the first col has full height, and there is another one
    // later that also does, then we can interpolate between those, up
    // to but not including the second full height column.  Then we
    // drop and return the columns we interpolated, leaving the second
    // full-height col as the first col in the buffer. And repeat as
    // long as enough columns are available.
    //
    // If the first col does not have full height, then (so long as
    // we're following the logic above) we must simply have not yet
    // reached the first full-height column in the CQ output, and we
    // can interpolate nothing.
    
    int width = m_buffer.size();
    int height = getTotalBins();

    if (width == 0) return out;
    
    int firstFullHeight = -1;
    int secondFullHeight = -1;

    for (int i = 0; i < width; ++i) {
	if ((int)m_buffer[i].size() == height) {
	    if (firstFullHeight == -1) {
		firstFullHeight = i;
	    } else if (secondFullHeight == -1) {
		secondFullHeight = i;
		break;
	    }
	}
    }

//    cerr << "fetchLinear: firstFullHeight = " << firstFullHeight << ", secondFullHeight = " << secondFullHeight << endl;

    if (firstFullHeight < 0) {
	if (insist) {
            return fetchHold(true);
	} else {
	    return out;
	}
    } else if (firstFullHeight > 0) {
	// can interpolate nothing, stash up to first full height & recurse
	out = RealBlock(m_buffer.begin(), m_buffer.begin() + firstFullHeight);
	m_buffer = RealBlock(m_buffer.begin() + firstFullHeight, m_buffer.end());
	RealBlock more = fetchLinear(insist);
	out.insert(out.end(), more.begin(), more.end());
	return out;
    } else if (secondFullHeight < 0) {
	// firstFullHeight == 0, but there is no second full height --
	// wait for it unless insist flag is set
	if (insist) {
            return fetchHold(true);
	} else {
	    return out;
	}
    } else {
	// firstFullHeight == 0 and secondFullHeight also valid. Can interpolate
	out = linearInterpolated(m_buffer, 0, secondFullHeight);
	m_buffer = RealBlock(m_buffer.begin() + secondFullHeight, m_buffer.end());
	RealBlock more = fetchLinear(insist);
	out.insert(out.end(), more.begin(), more.end());
	return out;
    }
}

CQSpectrogram::RealBlock
CQSpectrogram::linearInterpolated(const RealBlock &g, int x0, int x1)
{
    // g must be a grid with full-height columns at x0 and x1

    if (x0 >= x1) {
	throw std::logic_error("x0 >= x1");
    }
    if (x1 >= (int)g.size()) {
	throw std::logic_error("x1 >= g.size()");
    }
    if (g[x0].size() != g[x1].size()) {
	throw std::logic_error("x0 and x1 are not the same height");
    }

    int height = g[x0].size();
    int width = x1 - x0;

    RealBlock out(g.begin() + x0, g.begin() + x1);

    for (int y = 0; y < height; ++y) {

	int spacing = width;
	for (int i = 1; i < width; ++i) {
	    int thisHeight = g[x0 + i].size();
	    if (thisHeight > height) {
		throw std::logic_error("First column not full-height");
	    }
	    if (thisHeight > y) {
		spacing = i;
		break;
	    }
	}

	if (spacing < 2) continue;

	for (int i = 0; i + spacing <= width; i += spacing) {
	    for (int j = 1; j < spacing; ++j) {
		double proportion = double(j)/double(spacing);
		double interpolated = 
		    g[x0 + i][y] * (1.0 - proportion) +
		    g[x0 + i + spacing][y] * proportion;
		out[i + j].push_back(interpolated);
	    }
	}
    }

    return out;
}