[xiph-cvs] cvs commit: speex/libspeex mdf.c speex_echo.h
Jean-Marc Valin
jm at xiph.org
Mon Aug 18 14:52:15 PDT 2003
jm 03/08/18 17:52:15
Added: libspeex mdf.c speex_echo.h
Log:
Initial checkin of MDF-based echo canceller (still incomplete)
Revision Changes Path
1.1 speex/libspeex/mdf.c
Index: mdf.c
===================================================================
/* Copyright (C) Jean-Marc Valin
File: speex_echo.c
<p> Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include "misc.h"
#include "speex_echo.h"
#include "smallft.h"
#include <math.h>
/** Creates a new echo canceller state */
SpeexEchoState *speex_echo_state_init(int frame_size, int filter_length)
{
int N,M;
SpeexEchoState *st = (SpeexEchoState *)speex_alloc(sizeof(SpeexEchoState));
st->frame_size = frame_size;
st->window_size = 2*frame_size;
N = st->window_size;
M = st->M = (filter_length+N-1)/frame_size;
drft_init(&st->fft_lookup, N);
st->x = (float*)speex_alloc(N*sizeof(float));
st->y = (float*)speex_alloc(N*sizeof(float));
st->X = (float*)speex_alloc(M*N*sizeof(float));
st->Y = (float*)speex_alloc(N*sizeof(float));
st->E = (float*)speex_alloc(N*sizeof(float));
st->W = (float*)speex_alloc(M*N*sizeof(float));
st->PHI = (float*)speex_alloc(N*sizeof(float));
return st;
}
/** Destroys an echo canceller state */
void speex_echo_state_destroy(SpeexEchoState *st)
{
}
/** Performs echo cancellation a frame */
void speex_echo_cancel(SpeexEchoState *st, float *ref, float *echo, float *out, float *Yout)
{
int i,j;
int N,M;
float scale;
N = st->window_size;
M = st->M;
scale = 1.0/N;
for (i=0;i<st->frame_size;i++)
{
st->x[i] = st->x[i+st->frame_size];
st->x[i+st->frame_size] = echo[i];
}
/* Shift memory: this could be optimized eventually*/
for (i=0;i<N*(M-1);i++)
st->X[i]=st->X[i+N];
for (i=0;i<N;i++)
st->X[(M-1)*N+i]=st->x[i];
drft_forward(&st->fft_lookup, &st->X[(M-1)*N]);
for (i=1;i<N-1;i+=2)
{
st->Y[i] = st->Y[i+1] = 0;
for (j=0;j<M;j++)
{
st->Y[i] += st->X[j*N+i]*st->W[j*N+i] - st->X[j*N+i+1]*st->W[j*N+i+1];
st->Y[i+1] += st->X[j*N+i+1]*st->W[j*N+i] + st->X[j*N+i]*st->W[j*N+i+1];
}
}
st->Y[0] = st->Y[N-1] = 0;
if (Yout)
for (i=0;i<N;i++)
Yout[i] = st->Y[i];
for (i=0;i<N;i++)
st->y[i] = st->Y[i];
#if 0
for (i=0;i<N;i++)
st->y[i] = st->X[(M-1)*N+i];
#endif
drft_backward(&st->fft_lookup, st->y);
for (i=0;i<N;i++)
st->y[i] *= scale;
for (i=0;i<st->frame_size;i++)
{
out[i] = ref[i] - st->y[i+st->frame_size];
st->E[i] = 0;
st->E[i+st->frame_size] = out[i];
}
drft_forward(&st->fft_lookup, st->E);
for (j=0;j<M;j++)
{
for (i=1;i<N-1;i+=2)
{
st->PHI[i] = st->X[j*N+i]*st->E[i] + st->X[j*N+i+1]*st->E[i+1];
st->PHI[i+1] = -st->X[j*N+i+1]*st->E[i] + st->X[j*N+i]*st->E[i+1];
}
st->PHI[0] = st->PHI[N-1] = 0;
/* Optionally perform some transform (normalization?) on PHI */
for (i=0;i<N;i++)
st->W[j*N+i] += .002*st->PHI[i];
}
}
<p><p><p>1.1 speex/libspeex/speex_echo.h
Index: speex_echo.h
===================================================================
/* Copyright (C) Jean-Marc Valin
File: speex_echo.h
<p> Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
#include "smallft.h"
typedef struct SpeexEchoState {
int frame_size; /**< Number of samples processed each time */
int window_size;
int M;
float *x;
float *X;
float *y;
float *Y;
float *E;
float *PHI;
float *W;
drft_lookup fft_lookup;
<p>} SpeexEchoState;
<p>/** Creates a new echo canceller state */
SpeexEchoState *speex_echo_state_init(int frame_size, int filter_length);
/** Destroys an echo canceller state */
void speex_echo_state_destroy(SpeexEchoState *st);
/** Performs echo cancellation a frame */
void speex_echo_cancel(SpeexEchoState *st, float *ref, float *echo, float *out, float *Y);
<p><p><p>--- >8 ----
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