opus/libcelt/pitch.c
2007-12-10 17:57:19 +11:00

87 lines
2.2 KiB
C

/**
@file pitch.c
@brief Pitch analysis
*/
/* Copyright (C) 2005
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <math.h>
#include "fftwrap.h"
#include "pitch.h"
#include "psy.h"
void find_spectral_pitch(void *fft, float *x, float *y, int lag, int len, int C, int *pitch)
{
int c;
int n2 = lag/2;
float xx[lag*C];
float yy[lag*C];
float X[lag*C];
float Y[lag*C];
float curve[n2*C];
int i;
for (i=0;i<C*lag;i++)
xx[i] = 0;
for (c=0;c<C;c++)
{
for (i=0;i<len;i++)
xx[c*lag+i] = x[C*i+c];
for (i=0;i<lag;i++)
yy[c*lag+i] = y[C*i+c];
}
spx_fft(fft, xx, X);
spx_fft(fft, yy, Y);
compute_masking(X, curve, lag*C, 44100);
X[0] = 0;
for (i=1;i<C*n2;i++)
{
float n;
//n = 1.f/(1e1+sqrt(sqrt((X[2*i-1]*X[2*i-1] + X[2*i ]*X[2*i ])*(Y[2*i-1]*Y[2*i-1] + Y[2*i ]*Y[2*i ]))));
//n = 1;
n = 1.f/pow(1+curve[i],.5)/(i+60);
//n = 1.f/(1+curve[i]);
float tmp = X[2*i-1];
X[2*i-1] = (X[2*i-1]*Y[2*i-1] + X[2*i ]*Y[2*i ])*n;
X[2*i ] = (- X[2*i ]*Y[2*i-1] + tmp*Y[2*i ])*n;
}
X[C*lag-1] = 0;
X[0] = X[C*lag-1] = 0;
spx_ifft(fft, X, xx);
float max_corr=-1e10;
//int pitch;
*pitch = 0;
for (i=0;i<lag-len;i++)
{
//printf ("%f ", xx[i]);
if (xx[i] > max_corr)
{
*pitch = i;
max_corr = xx[i];
}
}
//printf ("\n");
//printf ("%d %f\n", *pitch, max_corr);
//printf ("%d\n", *pitch);
}