annotate src/Finder.cpp @ 147:3673e2dae6a7 structure

Factor out getBestEdgeCost

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Vamp feature extraction plugin using the MATCH audio alignment
    algorithm.

    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2007 Simon Dixon, Chris Cannam and QMUL.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#include "Finder.h"

#include "Path.h"

#include <algorithm>
#include <iomanip>

using namespace std;

//#define DEBUG_FINDER 1
//#define PERFORM_ERROR_CHECKS 1

Finder::Finder(Matcher *pm)
{
    m_m = pm;
    m_duration1 = -1;
    m_duration2 = -1;
} // constructor

Finder::~Finder()
{
}

void
Finder::setDurations(int d1, int d2)
{
#ifdef DEBUG_FINDER
    cerr << "*** setDurations: " << d1 << ", " << d2 << endl;
#endif
    m_duration1 = d1;
    m_duration2 = d2;
}

void
Finder::getBestEdgeCost(int row, int col,
                        int &bestRow, int &bestCol,
                        double &min)
{
    min = m_m->getPathCost(row, col);
    
    bestRow = row;
    bestCol = col;

    pair<int, int> rowRange = m_m->getRowRange(col);
    if (rowRange.second > row+1) {
        rowRange.second = row+1;	// don't cheat by looking at future :)
    }
    for (int index = rowRange.first; index < rowRange.second; index++) {
        double tmp = m_m->getNormalisedPathCost(index, col);
        if (tmp < min) {
            min = tmp;
            bestRow = index;
        }
    }

    pair<int, int> colRange = m_m->getColRange(row);
    if (colRange.second > col+1) {
        colRange.second = col+1;	// don't cheat by looking at future :)
    }
    for (int index = colRange.first; index < colRange.second; index++) {
        double tmp = m_m->getNormalisedPathCost(row, index);
        if (tmp < min) {
            min = tmp;
            bestCol = index;
            bestRow = row;
        }
    }
}

Matcher::Advance
Finder::getExpandDirection(int row, int col)
{
    // To determine which direction to expand the search area in, we
    // look at the path costs along the leading edges of the search
    // area (the final row and column within the area). We find the
    // lowest path cost within the final row, and the lowest within
    // the final column, and we compare them. If the row is cheaper
    // then we expand by adding another row next to it; if the column
    // is cheaper then we expand by adding another column next to
    // it. (The overall lowest path cost across the row and column
    // represents the best alignment we have within the entire search
    // area given the data available and the assumption that the piece
    // is not ending yet.)

    int bestRow = row;
    int bestCol = col;
    double bestCost = -1;

    getBestEdgeCost(row, col, bestRow, bestCol, bestCost);

//    cerr << "at [" << row << "," << col << "] (cost " << m_m->getPathCost(row, col) << ") blocksize = " << m_m->getBlockSize() << " best is [" << bestRow << "," << bestCol << "] (cost " << bestCost << ")" << endl;
    
    if (bestRow == row) {
        if (bestCol == col) {
            return Matcher::AdvanceBoth;
        } else {
            return Matcher::AdvanceThis;
        }
    } else if (bestCol == col) {
        return Matcher::AdvanceOther;
    } else {
        return Matcher::AdvanceNone;
    }
}

void
Finder::recalculatePathCostMatrix(int r1, int c1, int r2, int c2) 
{
    int prevRowStart = 0, prevRowStop = 0;

    float diagonalWeight = m_m->getDiagonalWeight();
    
    for (int r = r1; r <= r2; r++) {

        pair<int, int> colRange = m_m->getColRange(r);

        int rowStart = max(c1, colRange.first);
        int rowStop = min(c2 + 1, colRange.second);
        
        for (int c = rowStart; c < rowStop; c++) {

            float newCost = m_m->getDistance(r, c);
            Matcher::Advance dir = Matcher::AdvanceNone;

            if (r > r1) {	// not first row
                double min = -1;
                if ((c > prevRowStart) && (c <= prevRowStop)) {
                    // diagonal from (r-1,c-1)
                    min = m_m->getPathCost(r-1, c-1) + newCost * diagonalWeight;
                    dir = Matcher::AdvanceBoth;
                }
                if ((c >= prevRowStart) && (c < prevRowStop)) {
                    // vertical from (r-1,c)
                    double cost = m_m->getPathCost(r-1, c) + newCost;
                    if ((min < 0) || (cost < min)) {
                        min = cost;
                        dir = Matcher::AdvanceThis;
                    }
                }
                if (c > rowStart) {
                    // horizontal from (r,c-1)
                    double cost = m_m->getPathCost(r, c-1) + newCost;
                    if ((min < 0) || (cost < min)) {
                        min = cost;
                        dir = Matcher::AdvanceOther;
                    }
                }
                
                m_m->setPathCost(r, c, dir, min);

            } else if (c > rowStart) {	// first row
                // horizontal from (r,c-1)
                m_m->setPathCost(r, c, Matcher::AdvanceOther,
                                   m_m->getPathCost(r, c-1) + newCost);
            }
        }

        prevRowStart = rowStart;
        prevRowStop = rowStop;
    }
} 

#ifdef PERFORM_ERROR_CHECKS
Finder::ErrorPosition
Finder::checkPathCostMatrix() 
{
    ErrorPosition err;

    int r1 = 0;
    int c1 = 0;
    int r2 = m_m->getFrameCount() - 1;
    int c2 = m_m->getOtherFrameCount() - 1;

    if (r2 < r1 || c2 < c1) {
        return err;
    }

    int prevRowStart = 0, prevRowStop = 0;

    float diagonalWeight = m_m->getDiagonalWeight();
    
    for (int r = r1; r <= r2; r++) {

        pair<int, int> colRange = m_m->getColRange(r);

        int rowStart = max(c1, colRange.first);
        int rowStop = min(c2 + 1, colRange.second);
        
        for (int c = rowStart; c < rowStop; c++) {

            float newCost = m_m->getDistance(r, c);
            double updateTo = -1.0;
            Matcher::Advance dir = Matcher::AdvanceNone;

            if (r > r1) { // not first row
                double min = -1;
                if ((c > prevRowStart) && (c <= prevRowStop)) {
                    // diagonal from (r-1,c-1)
                    min = m_m->getPathCost(r-1, c-1) + newCost * diagonalWeight;
                    err.prevCost = m_m->getPathCost(r-1, c-1);
                    err.distance = newCost * diagonalWeight;
                    dir = Matcher::AdvanceBoth;
                }
                if ((c >= prevRowStart) && (c < prevRowStop)) {
                    // vertical from (r-1,c)
                    double cost = m_m->getPathCost(r-1, c) + newCost;
                    if ((min < 0) || (cost < min)) {
                        min = cost;
                        err.prevCost = m_m->getPathCost(r-1, c);
                        err.distance = newCost;
                        dir = Matcher::AdvanceThis;
                    }
                }
                if (c > rowStart) {
                    // horizontal from (r,c-1)
                    double cost = m_m->getPathCost(r, c-1) + newCost;
                    if ((min < 0) || (cost < min)) {
                        min = cost;
                        err.prevCost = m_m->getPathCost(r, c-1);
                        err.distance = newCost;
                        dir = Matcher::AdvanceOther;
                    }
                }

                updateTo = min;

            } else { // first row

                if (c > rowStart) {
                    // horizontal from (r,c-1)
                    updateTo = m_m->getPathCost(r, c-1) + newCost;
                    err.prevCost = m_m->getPathCost(r, c-1);
                    err.distance = newCost;
                    dir = Matcher::AdvanceOther;
                }
            }

            if (dir != Matcher::AdvanceNone) {
                if (m_m->getAdvance(r, c) != dir) {
                    err.type = ErrorPosition::WrongAdvance;
                    err.r = r;
                    err.c = c;
                    err.costWas = m_m->getPathCost(r, c);
                    err.costShouldBe = updateTo;
                    err.advanceWas = m_m->getAdvance(r, c);
                    err.advanceShouldBe = dir;
                    return err;
                }
                if (m_m->getPathCost(r, c) != updateTo) {
                    err.type = ErrorPosition::WrongCost;
                    err.r = r;
                    err.c = c;
                    err.costWas = m_m->getPathCost(r, c);
                    err.costShouldBe = updateTo;
                    err.advanceWas = m_m->getAdvance(r, c);
                    err.advanceShouldBe = dir;
                    return err;
                }
            } else {
                // AdvanceNone should occur only at r = r1, c = c1
                if (r != r1 || c != c1) {
                    err.type = ErrorPosition::NoAdvance;
                    err.r = r;
                    err.c = c;
                    err.costWas = m_m->getPathCost(r, c);
                    err.costShouldBe = updateTo;
                    err.advanceWas = m_m->getAdvance(r, c);
                    err.advanceShouldBe = dir;
                    return err;
                }
            }
        }

        prevRowStart = rowStart;
        prevRowStop = rowStop;
    }

    return err;
}

void
Finder::checkAndReport()
{
    cerr << "Finder: Checking path-cost matrix..." << endl;
    ErrorPosition err = checkPathCostMatrix();
    if (err.type == ErrorPosition::NoError) {
        cerr << "No errors found" << endl;
    } else {
        cerr << "\nWARNING: Checking path-cost matrix returned mismatch:" << endl;
        cerr << "Type: " << err.type << ": ";
        switch (err.type) {
        case ErrorPosition::NoError: break;
        case ErrorPosition::WrongCost: cerr << "WrongCost"; break;
        case ErrorPosition::WrongAdvance: cerr << "WrongAdvance"; break;
        case ErrorPosition::NoAdvance: cerr << "NoAdvance"; break;
        }
        cerr << endl;
        cerr << "At row " << err.r << ", column " << err.c
             << "\nShould be advancing "
             << Matcher::advanceToString(err.advanceShouldBe)
             << ", advance in matrix is "
             << Matcher::advanceToString(err.advanceWas)
             << "\nPrev cost " << err.prevCost
             << " plus distance " << err.distance << " gives "
             << err.costShouldBe << ", matrix contains " << err.costWas
             << endl;
        cerr << "Note: diagonal weight = " << m_m->getDiagonalWeight() << endl;
        cerr << endl;

        int w(4);
        int ww(15);

        cerr << "Distance matrix leading up to this point:" << endl;
        cerr << setprecision(12) << setw(w) << "";
        for (int i = -4; i <= 0; ++i) {
            cerr << setw(ww) << i;
        }
        cerr << endl;
        for (int j = -4; j <= 0; ++j) {
            cerr << setw(w) << j;
            for (int i = -4; i <= 0; ++i) {
                cerr << setw(ww) << m_m->getDistance(err.r + j, err.c + i);
            }
            cerr << endl;
        }
        cerr << endl;

        cerr << "Cost matrix leading up to this point:" << endl;
        cerr << setw(w) << "";
        for (int i = -4; i <= 0; ++i) {
            cerr << setw(ww) << i;
        }
        cerr << endl;
        for (int j = -4; j <= 0; ++j) {
            cerr << setw(w) << j;
            for (int i = -4; i <= 0; ++i) {
                cerr << setw(ww) << m_m->getPathCost(err.r + j, err.c + i);
            }
            cerr << endl;
        }
        cerr << endl;
    }
}
#endif

int
Finder::retrievePath(bool smooth, vector<int> &pathx, vector<int> &pathy)
{
    pathx.clear();
    pathy.clear();

#ifdef PERFORM_ERROR_CHECKS
    checkAndReport();
#endif

    int ex = m_m->getOtherFrameCount() - 1;
    int ey = m_m->getFrameCount() - 1;

    if (ex < 0 || ey < 0) {
        return 0;
    }
    
    int x = ex;
    int y = ey;

#ifdef DEBUG_FINDER
    cerr << "*** retrievePath: smooth = " << smooth << endl;
    cerr << "*** retrievePath: before: x = " << x << ", y = " << y << endl;
#endif

    if (m_duration2 > 0 && m_duration2 < m_m->getOtherFrameCount()) {
        x = m_duration2 - 1;
    }
    if (m_duration1 > 0 && m_duration1 < m_m->getFrameCount()) {
        y = m_duration1 - 1;
    }

    if (!m_m->isAvailable(y, x)) {
        // Path did not pass through the expected end point --
        // probably means the pieces are substantially different in
        // the later bits. Reset the expected end point to the end of
        // both files including any trailing silence.
        cerr << "NOTE: Path did not pass through expected end point, inputs are probably significantly different" << endl;
        x = ex;
        y = ey;
    }

    recalculatePathCostMatrix(0, 0, y, x);

#ifdef DEBUG_FINDER
    cerr << "*** retrievePath: start: x = " << x << ", y = " << y << endl;
#endif
    
    while (m_m->isAvailable(y, x) && (x > 0 || y > 0)) {

//        cerr << "x = " << x << ", y = " << y;
        
        pathx.push_back(x);
        pathy.push_back(y);

        switch (m_m->getAdvance(y, x)) {
        case Matcher::AdvanceThis:
//            cerr << ", going down (dist = " << getDistance() << ")" << endl;
            y--;
            break;
        case Matcher::AdvanceOther:
//            cerr << ", going left (dist = " << getDistance() << ")" << endl;
            x--;
            break;
        case Matcher::AdvanceBoth:
//            cerr << ", going diag (dist = " << getDistance() << ")" << endl;
            x--;
            y--;
            break;
        case Matcher::AdvanceNone: // this would indicate a bug, but we wouldn't want to hang
            cerr << "WARNING: Neither matcher advanced in path backtrack at (" << x << "," << y << ")" << endl;
            if (x > y) {
                x--;
            } else {
                y--;
            }
            break;
        }
    }

    if (x > 0 || y > 0) {
        cerr << "WARNING: Ran out of available path at (" << y << "," << x
             << ")!" << endl;
    }
    
    reverse(pathx.begin(), pathx.end());
    reverse(pathy.begin(), pathy.end());

    if (smooth) {
        int smoothedLen = Path().smooth(pathx, pathy, pathx.size());
        return smoothedLen;
    } else {
        return pathx.size();
    }
}