Files
Vocaluxe/PitchTracker/pdaAKF.cpp
T
2014-03-29 22:54:37 +01:00

141 lines
4.5 KiB
C++

// This file is part of Vocaluxe.
//
// Vocaluxe 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 3 of the License, or
// (at your option) any later version.
//
// Vocaluxe is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Vocaluxe. If not, see <http://www.gnu.org/licenses/>.
#include "pdaAKF.h"
#include <math.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
namespace PitchTrackerAKF{
static void doLog(const char* msg,...){
va_list argptr = NULL;
va_start(argptr, msg);
char buffer[200];
vsprintf_s(buffer,msg, argptr);
if(Log) Log(buffer);
va_end(argptr);
}
void SetLogCallback(LogCallback Callback){
Log=Callback;
}
static double *SamplesPerPeriodPerTone = NULL;
static double BaseToneFrequency = -1;
static int MinHalfTone = -1, MaxHalfTone = -1;
static const double HalftoneBase = 1.05946309436; // 2^(1/12) -> HalftoneBase^12 = 2 (one octave)
void Init(double baseToneFrequency, int minHalfTone, int maxHalfTone){
if(SamplesPerPeriodPerTone && abs(baseToneFrequency - BaseToneFrequency) < 1. && minHalfTone == MinHalfTone && maxHalfTone == MaxHalfTone)
return;
BaseToneFrequency = baseToneFrequency;
MinHalfTone = minHalfTone;
MaxHalfTone = maxHalfTone;
DeInit();
if(minHalfTone < 0 || maxHalfTone < minHalfTone)
return;
SamplesPerPeriodPerTone = (double*) malloc((MaxHalfTone + 1) * sizeof(double));
//Init Array to avoid costly calculations
for (int toneIndex = 0; toneIndex <= MaxHalfTone; toneIndex++)
{
double freq = baseToneFrequency * pow(HalftoneBase, toneIndex);
SamplesPerPeriodPerTone[toneIndex] = 44100.0 / freq; // samples in one period
}
}
void DeInit(){
if(SamplesPerPeriodPerTone){
free(SamplesPerPeriodPerTone);
SamplesPerPeriodPerTone=NULL;
}
}
template<typename T>
static T _AnalyzeToneFunc(T *samples, int sampleCt, int toneIndex, bool scale){
// Use method by Kobayashi and Shimamura (1995): Combine AKF and AMDF to a new f(z)=AKF(z)/(AMDF(z)+k) with k=1
double samplesPerPeriodD = SamplesPerPeriodPerTone[toneIndex]; // samples in one period
int samplesPerPeriod = static_cast<int>(samplesPerPeriodD);
T fHigh = static_cast<T>(samplesPerPeriodD - samplesPerPeriod);
T fLow = static_cast<T>(1.0 - fHigh);
T accumDistAKF = 0; // accumulated distances
T accumDistAMDF = 0; // accumulated distances
// compare correlating samples
int sampleIndex = 0; // index of sample to analyze
// Start value= index of sample one period ahead
for (int correlatingSampleIndex = sampleIndex + samplesPerPeriod; correlatingSampleIndex + 1 < sampleCt; correlatingSampleIndex++, sampleIndex++)
{
// calc distance to corresponding sample in next period
T xn = samples[sampleIndex];
T xnt = samples[correlatingSampleIndex] * fLow + samples[correlatingSampleIndex + 1] * fHigh;
accumDistAKF += xn * xnt;
accumDistAMDF += abs(xn - xnt);
}
accumDistAKF /= sampleCt;
accumDistAMDF /= sampleIndex;
if(scale)
return accumDistAKF / (accumDistAMDF * 32767.f + 32767.f); // Need to scale AKF by MAX^2 and AMDF by MAX, so do some maths to divide only once
else
return accumDistAKF / (accumDistAMDF + 1.f);
}
template<typename T>
int GetTone(T *samples, int sampleCt, double* maxVolume, float *weights, bool scale){
if(!SamplesPerPeriodPerTone)
return -1;
T maxVolumeL = 0;
for(int i = 0; i < sampleCt; i++){
T vol = abs(samples[i]);
if(vol > maxVolumeL)
maxVolumeL = vol;
}
if(scale)
maxVolumeL /= 32767.;
*maxVolume = maxVolumeL;
T maxWeight = -1;
T minWeight = 1;
int maxTone = -1;
for (int toneIndex = MinHalfTone; toneIndex <= MaxHalfTone; toneIndex++)
{
T curWeight = _AnalyzeToneFunc<T>(samples, sampleCt, toneIndex, scale);
if (curWeight > maxWeight)
{
maxWeight = curWeight;
maxTone = toneIndex;
}
if (curWeight < minWeight)
minWeight = curWeight;
weights[toneIndex - MinHalfTone] = static_cast<float>(curWeight);
}
if(maxWeight - minWeight > 0.01){
return maxTone;
}else return -1;
}
template int GetTone(float *samples, int sampleCt, double* maxVolume, float *weights, bool scale);
template int GetTone(double *samples, int sampleCt, double* maxVolume, float *weights, bool scale);
}