ref: 2c1d2f5bcc17d1442bcde442cbdfc6808e748603
parent: b8e5c4c658af6b69ecfd8a97610899d840588428
author: Jean-Marc Valin <[email protected]>
date: Fri Feb 22 16:45:16 EST 2008
MDCT now scales down by N/2 instead of N/4. The factor two is moved to the overlap-add during synthesis.
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -210,9 +210,9 @@
for (j=0;j<2*N;j++)
x[j] = window[j]*x[j];
for (j=0;j<overlap;j++)
- out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] = x[N4+j]+mdct_overlap[C*j+c];
+ out_mem[C*(MAX_PERIOD+(i-B)*N)+C*j+c] = 2*(x[N4+j]+mdct_overlap[C*j+c]);
for (j=0;j<2*N4;j++)
- out_mem[C*(MAX_PERIOD+(i-B)*N)+C*(j+overlap)+c] = x[j+N4+overlap];
+ out_mem[C*(MAX_PERIOD+(i-B)*N)+C*(j+overlap)+c] = 2*x[j+N4+overlap];
for (j=0;j<overlap;j++)
mdct_overlap[C*j+c] = x[N+N4+j];
}
--- a/libcelt/mdct.c
+++ b/libcelt/mdct.c
@@ -93,8 +93,8 @@
{float re, im;
/* Real part arranged as -d-cR, Imag part arranged as -b+aR*/
- re = -in[N2+N4+2*i] - in[N2+N4-2*i-1];
- im = -in[N4+2*i] + in[N4-2*i-1];
+ re = -.5*(in[N2+N4+2*i] + in[N2+N4-2*i-1]);
+ im = -.5*(in[N4+2*i] - in[N4-2*i-1]);
out[2*i] = re*l->trig[i] - im*l->trig[i+N4];
out[2*i+1] = im*l->trig[i] + re*l->trig[i+N4];
}
@@ -102,8 +102,8 @@
{float re, im;
/* Real part arranged as a-bR, Imag part arranged as -c-dR */
- re = in[2*i-N4] - in[N2+N4-2*i-1];
- im = -(in[N4+2*i] + in[N+N4-2*i-1]);
+ re = .5*(in[2*i-N4] - in[N2+N4-2*i-1]);
+ im = -.5*(in[N4+2*i] + in[N+N4-2*i-1]);
out[2*i] = re*l->trig[i] - im*l->trig[i+N4];
out[2*i+1] = im*l->trig[i] + re*l->trig[i+N4];
}
@@ -147,6 +147,7 @@
float re, im;
re = f[2*i];
im = f[2*i+1];
+ /* We'd scale up by 2 here, but instead it's done when mixing the windows */
f[2*i] = re*l->trig[i] + im*l->trig[i+N4];
f[2*i+1] = im*l->trig[i] - re*l->trig[i+N4];
}
--- a/tests/dft-test.c
+++ b/tests/dft-test.c
@@ -5,11 +5,12 @@
#include <stdio.h>
#include "kiss_fft.h"
+int ret = 0;
void check(kiss_fft_cpx * in,kiss_fft_cpx * out,int nfft,int isinverse)
{int bin,k;
- double errpow=0,sigpow=0;
+ double errpow=0,sigpow=0, snr;
for (bin=0;bin<nfft;++bin) {double ansr = 0;
@@ -41,7 +42,12 @@
errpow += difr*difr + difi*difi;
sigpow += ansr*ansr+ansi*ansi;
}
- printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,10*log10(sigpow/errpow) );+ snr = 10*log10(sigpow/errpow);
+ printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,snr );+ if (snr<60) {+ printf( "** poor snr: %f ** \n", snr);
+ ret = 1;
+ }
}
void test1d(int nfft,int isinverse)
@@ -109,5 +115,5 @@
test1d(105,0);
test1d(105,1);
}
- return 0;
+ return ret;
}
--- a/tests/mdct-test.c
+++ b/tests/mdct-test.c
@@ -5,12 +5,12 @@
#include <stdio.h>
#include "mdct.h"
-
+int ret = 0;
void check(float * in,float * out,int nfft,int isinverse)
{int bin,k;
double errpow=0,sigpow=0;
-
+ double snr;
for (bin=0;bin<nfft/2;++bin) {double ansr = 0;
double difr;
@@ -19,7 +19,7 @@
double phase = 2*M_PI*(k+.5+.25*nfft)*(bin+.5)/nfft;
double re = cos(phase);
- re /= nfft/4;
+ re /= nfft/2;
ansr += in[k] * re;
}
@@ -28,7 +28,12 @@
errpow += difr*difr;
sigpow += ansr*ansr;
}
- printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,10*log10(sigpow/errpow) );+ snr = 10*log10(sigpow/errpow);
+ printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,snr );+ if (snr<60) {+ printf( "** poor snr: %f **\n", snr);
+ ret = 1;
+ }
}
void check_inv(float * in,float * out,int nfft,int isinverse)
@@ -35,7 +40,7 @@
{int bin,k;
double errpow=0,sigpow=0;
-
+ double snr;
for (bin=0;bin<nfft;++bin) {double ansr = 0;
double difr;
@@ -43,7 +48,9 @@
for (k=0;k<nfft/2;++k) {double phase = 2*M_PI*(bin+.5+.25*nfft)*(k+.5)/nfft;
double re = cos(phase);
-
+
+ //re *= 2;
+
ansr += in[k] * re;
}
/*printf ("%f %f\n", ansr, out[bin]);*/@@ -51,7 +58,12 @@
errpow += difr*difr;
sigpow += ansr*ansr;
}
- printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,10*log10(sigpow/errpow) );+ snr = 10*log10(sigpow/errpow);
+ printf("nfft=%d inverse=%d,snr = %f\n",nfft,isinverse,snr );+ if (snr<60) {+ printf( "** poor snr: %f **\n", snr);
+ ret = 1;
+ }
}
@@ -112,13 +124,20 @@
}else{test1d(32,0);
test1d(32,1);
- exit(0);
- test1d(36,0);
- test1d(36,1);
- test1d(50,0);
- test1d(50,1);
+ test1d(40,0);
+ test1d(40,1);
+ test1d(56,0);
+ test1d(56,1);
test1d(120,0);
test1d(120,1);
+ test1d(240,0);
+ test1d(240,1);
+ test1d(256,0);
+ test1d(256,1);
+ test1d(480,0);
+ test1d(480,1);
+ test1d(512,0);
+ test1d(512,1);
}
- return 0;
+ return ret;
}
--- a/tests/real-fft-test.c
+++ b/tests/real-fft-test.c
@@ -10,6 +10,8 @@
#include <stdio.h>
#include <string.h>
+int ret=0;
+
static double cputime(void)
{struct tms t;
@@ -44,9 +46,9 @@
}
snr = 10*log10( sigpow / noisepow );
- if (snr<10) {- printf( "\npoor snr: %f\n", snr);
- exit(1);
+ if (snr<60) {+ printf( "** poor snr: %f **\n", snr);
+ ret = 1;
}
return snr;
}
@@ -63,9 +65,9 @@
noisepow += err * err;
}
snr = 10*log10( sigpow / noisepow );
- if (snr<10) {+ if (snr<60) {printf( "\npoor snr: %f\n", snr);
- exit(1);
+ ret = 1;
}
return snr;
}
@@ -184,5 +186,5 @@
free(kiss_fft_state);
free(kiss_fftr_state);
- return 0;
+ return ret;
}