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/**********************************************************************
resample.c
Real-time library interface by Dominic Mazzoni
Based on resample-1.7:
http://www-ccrma.stanford.edu/~jos/resample/
License: LGPL - see the file LICENSE.txt for more information
This is the main source file, implementing all of the API
functions and handling all of the buffering logic.
**********************************************************************/
/* External interface */
#include "../include/libresample.h"
/* Definitions */
#include "resample_defs.h"
#include "filterkit.h"
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
typedef struct {
float *Imp;
float *ImpD;
float LpScl;
UWORD Nmult;
UWORD Nwing;
double minFactor;
double maxFactor;
UWORD XSize;
float *X;
UWORD Xp; /* Current "now"-sample pointer for input */
UWORD Xread; /* Position to put new samples */
UWORD Xoff;
UWORD YSize;
float *Y;
UWORD Yp;
double Time;
} rsdata;
void *resample_dup(const void * handle)
{
const rsdata *cpy = (const rsdata *)handle;
rsdata *hp = (rsdata *)malloc(sizeof(rsdata));
hp->minFactor = cpy->minFactor;
hp->maxFactor = cpy->maxFactor;
hp->Nmult = cpy->Nmult;
hp->LpScl = cpy->LpScl;
hp->Nwing = cpy->Nwing;
hp->Imp = (float *)malloc(hp->Nwing * sizeof(float));
memcpy(hp->Imp, cpy->Imp, hp->Nwing * sizeof(float));
hp->ImpD = (float *)malloc(hp->Nwing * sizeof(float));
memcpy(hp->ImpD, cpy->ImpD, hp->Nwing * sizeof(float));
hp->Xoff = cpy->Xoff;
hp->XSize = cpy->XSize;
hp->X = (float *)malloc((hp->XSize + hp->Xoff) * sizeof(float));
memcpy(hp->X, cpy->X, (hp->XSize + hp->Xoff) * sizeof(float));
hp->Xp = cpy->Xp;
hp->Xread = cpy->Xread;
hp->YSize = cpy->YSize;
hp->Y = (float *)malloc(hp->YSize * sizeof(float));
memcpy(hp->Y, cpy->Y, hp->YSize * sizeof(float));
hp->Yp = cpy->Yp;
hp->Time = cpy->Time;
return (void *)hp;
}
void *resample_open(int highQuality, double minFactor, double maxFactor)
{
double *Imp64;
double Rolloff, Beta;
rsdata *hp;
UWORD Xoff_min, Xoff_max;
int i;
/* Just exit if we get invalid factors */
if (minFactor <= 0.0 || maxFactor <= 0.0 || maxFactor < minFactor) {
#if DEBUG
fprintf(stderr,
"libresample: "
"minFactor and maxFactor must be positive real numbers,\n"
"and maxFactor should be larger than minFactor.\n");
#endif
return 0;
}
hp = (rsdata *)malloc(sizeof(rsdata));
hp->minFactor = minFactor;
hp->maxFactor = maxFactor;
if (highQuality)
hp->Nmult = 35;
else
hp->Nmult = 11;
hp->LpScl = 1.0;
hp->Nwing = Npc*(hp->Nmult-1)/2; /* # of filter coeffs in right wing */
Rolloff = 0.90;
Beta = 6;
Imp64 = (double *)malloc(hp->Nwing * sizeof(double));
lrsLpFilter(Imp64, hp->Nwing, 0.5*Rolloff, Beta, Npc);
hp->Imp = (float *)malloc(hp->Nwing * sizeof(float));
hp->ImpD = (float *)malloc(hp->Nwing * sizeof(float));
for(i=0; i<hp->Nwing; i++)
hp->Imp[i] = Imp64[i];
/* Storing deltas in ImpD makes linear interpolation
of the filter coefficients faster */
for (i=0; i<hp->Nwing-1; i++)
hp->ImpD[i] = hp->Imp[i+1] - hp->Imp[i];
/* Last coeff. not interpolated */
hp->ImpD[hp->Nwing-1] = - hp->Imp[hp->Nwing-1];
free(Imp64);
/* Calc reach of LP filter wing (plus some creeping room) */
Xoff_min = ((hp->Nmult+1)/2.0) * MAX(1.0, 1.0/minFactor) + 10;
Xoff_max = ((hp->Nmult+1)/2.0) * MAX(1.0, 1.0/maxFactor) + 10;
hp->Xoff = MAX(Xoff_min, Xoff_max);
/* Make the inBuffer size at least 4096, but larger if necessary
in order to store the minimum reach of the LP filter and then some.
Then allocate the buffer an extra Xoff larger so that
we can zero-pad up to Xoff zeros at the end when we reach the
end of the input samples. */
hp->XSize = MAX(2*hp->Xoff+10, 4096);
hp->X = (float *)malloc((hp->XSize + hp->Xoff) * sizeof(float));
hp->Xp = hp->Xoff;
hp->Xread = hp->Xoff;
/* Need Xoff zeros at begining of X buffer */
for(i=0; i<hp->Xoff; i++)
hp->X[i]=0;
/* Make the outBuffer long enough to hold the entire processed
output of one inBuffer */
hp->YSize = (int)(((double)hp->XSize)*maxFactor+2.0);
hp->Y = (float *)malloc(hp->YSize * sizeof(float));
hp->Yp = 0;
hp->Time = (double)hp->Xoff; /* Current-time pointer for converter */
return (void *)hp;
}
int resample_get_filter_width(const void *handle)
{
const rsdata *hp = (const rsdata *)handle;
return hp->Xoff;
}
int resample_process(void *handle,
double factor,
float *inBuffer,
int inBufferLen,
int lastFlag,
int *inBufferUsed, /* output param */
float *outBuffer,
int outBufferLen)
{
rsdata *hp = (rsdata *)handle;
float *Imp = hp->Imp;
float *ImpD = hp->ImpD;
float LpScl = hp->LpScl;
UWORD Nwing = hp->Nwing;
BOOL interpFilt = FALSE; /* TRUE means interpolate filter coeffs */
int outSampleCount;
UWORD Nout, Ncreep, Nreuse;
int Nx;
int i, len;
#if DEBUG
fprintf(stderr, "resample_process: in=%d, out=%d lastFlag=%d\n",
inBufferLen, outBufferLen, lastFlag);
#endif
/* Initialize inBufferUsed and outSampleCount to 0 */
*inBufferUsed = 0;
outSampleCount = 0;
if (factor < hp->minFactor || factor > hp->maxFactor) {
#if DEBUG
fprintf(stderr,
"libresample: factor %f is not between "
"minFactor=%f and maxFactor=%f",
factor, hp->minFactor, hp->maxFactor);
#endif
return -1;
}
/* Start by copying any samples still in the Y buffer to the output
buffer */
if (hp->Yp && (outBufferLen-outSampleCount)>0) {
len = MIN(outBufferLen-outSampleCount, hp->Yp);
for(i=0; i<len; i++)
outBuffer[outSampleCount+i] = hp->Y[i];
outSampleCount += len;
for(i=0; i<hp->Yp-len; i++)
hp->Y[i] = hp->Y[i+len];
hp->Yp -= len;
}
/* If there are still output samples left, return now - we need
the full output buffer available to us... */
if (hp->Yp)
return outSampleCount;
/* Account for increased filter gain when using factors less than 1 */
if (factor < 1)
LpScl = LpScl*factor;
for(;;) {
/* This is the maximum number of samples we can process
per loop iteration */
#ifdef DEBUG
printf("XSize: %d Xoff: %d Xread: %d Xp: %d lastFlag: %d\n",
hp->XSize, hp->Xoff, hp->Xread, hp->Xp, lastFlag);
#endif
/* Copy as many samples as we can from the input buffer into X */
len = hp->XSize - hp->Xread;
if (len >= (inBufferLen - (*inBufferUsed)))
len = (inBufferLen - (*inBufferUsed));
for(i=0; i<len; i++)
hp->X[hp->Xread + i] = inBuffer[(*inBufferUsed) + i];
*inBufferUsed += len;
hp->Xread += len;
if (lastFlag && (*inBufferUsed == inBufferLen)) {
/* If these are the last samples, zero-pad the
end of the input buffer and make sure we process
all the way to the end */
Nx = hp->Xread - hp->Xoff;
for(i=0; i<hp->Xoff; i++)
hp->X[hp->Xread + i] = 0;
}
else
Nx = hp->Xread - 2 * hp->Xoff;
#ifdef DEBUG
fprintf(stderr, "new len=%d Nx=%d\n", len, Nx);
#endif
if (Nx <= 0)
break;
/* Resample stuff in input buffer */
if (factor >= 1) { /* SrcUp() is faster if we can use it */
Nout = lrsSrcUp(hp->X, hp->Y, factor, &hp->Time, Nx,
Nwing, LpScl, Imp, ImpD, interpFilt);
}
else {
Nout = lrsSrcUD(hp->X, hp->Y, factor, &hp->Time, Nx,
Nwing, LpScl, Imp, ImpD, interpFilt);
}
#ifdef DEBUG
printf("Nout: %d\n", Nout);
#endif
hp->Time -= Nx; /* Move converter Nx samples back in time */
hp->Xp += Nx; /* Advance by number of samples processed */
/* Calc time accumulation in Time */
Ncreep = (int)(hp->Time) - hp->Xoff;
if (Ncreep) {
hp->Time -= Ncreep; /* Remove time accumulation */
hp->Xp += Ncreep; /* and add it to read pointer */
}
/* Copy part of input signal that must be re-used */
Nreuse = hp->Xread - (hp->Xp - hp->Xoff);
for (i=0; i<Nreuse; i++)
hp->X[i] = hp->X[i + (hp->Xp - hp->Xoff)];
#ifdef DEBUG
printf("New Xread=%d\n", Nreuse);
#endif
hp->Xread = Nreuse; /* Pos in input buff to read new data into */
hp->Xp = hp->Xoff;
/* Check to see if output buff overflowed (shouldn't happen!) */
if (Nout > hp->YSize) {
#ifdef DEBUG
printf("Nout: %d YSize: %d\n", Nout, hp->YSize);
#endif
fprintf(stderr, "libresample: Output array overflow!\n");
return -1;
}
hp->Yp = Nout;
/* Copy as many samples as possible to the output buffer */
if (hp->Yp && (outBufferLen-outSampleCount)>0) {
len = MIN(outBufferLen-outSampleCount, hp->Yp);
for(i=0; i<len; i++)
outBuffer[outSampleCount+i] = hp->Y[i];
outSampleCount += len;
for(i=0; i<hp->Yp-len; i++)
hp->Y[i] = hp->Y[i+len];
hp->Yp -= len;
}
/* If there are still output samples left, return now,
since we need the full output buffer available */
if (hp->Yp)
break;
}
return outSampleCount;
}
void resample_close(void *handle)
{
rsdata *hp = (rsdata *)handle;
free(hp->X);
free(hp->Y);
free(hp->Imp);
free(hp->ImpD);
free(hp);
}
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