ref: 4cb7d826e03ac02689c8c5240e7af5931b10a257
dir: /src/bend.c/
/* libSoX effect: Pitch Bend (c) 2008 robs@users.sourceforge.net
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Portions based on http://www.dspdimension.com/download smbPitchShift.cpp:
*
* COPYRIGHT 1999-2006 Stephan M. Bernsee <smb [AT] dspdimension [DOT] com>
*
* The Wide Open License (WOL)
*
* Permission to use, copy, modify, distribute and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice and this license appear in all source copies.
* THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY OF
* ANY KIND. See http://www.dspguru.com/wol.htm for more information.
*/
#ifdef NDEBUG /* Enable assert always. */
#undef NDEBUG /* Must undef above assert.h or other that might include it. */
#endif
#include "sox_i.h"
#include <assert.h>
#define MAX_FRAME_LENGTH 8192
typedef struct {
unsigned nbends; /* Number of bends requested */
struct {
char *str; /* Command-line argument to parse for this bend */
size_t start; /* Start bending when in_pos equals this */
double cents;
size_t duration; /* Number of samples to bend */
} *bends;
unsigned frame_rate;
size_t in_pos; /* Number of samples read from the input stream */
unsigned bends_pos; /* Number of bends completed so far */
double shift;
float gInFIFO[MAX_FRAME_LENGTH];
float gOutFIFO[MAX_FRAME_LENGTH];
double gFFTworksp[2 * MAX_FRAME_LENGTH];
float gLastPhase[MAX_FRAME_LENGTH / 2 + 1];
float gSumPhase[MAX_FRAME_LENGTH / 2 + 1];
float gOutputAccum[2 * MAX_FRAME_LENGTH];
float gAnaFreq[MAX_FRAME_LENGTH];
float gAnaMagn[MAX_FRAME_LENGTH];
float gSynFreq[MAX_FRAME_LENGTH];
float gSynMagn[MAX_FRAME_LENGTH];
long gRover;
int fftFrameSize, ovsamp;
} priv_t;
static int parse(sox_effect_t * effp, char **argv, sox_rate_t rate)
{
priv_t *p = (priv_t *) effp->priv;
size_t i, time = 0, delay;
char const *next;
for (i = 0; i < p->nbends; ++i) {
if (argv) /* 1st parse only */
p->bends[i].str = lsx_strdup(argv[i]);
next = lsx_parsesamples(rate, p->bends[i].str, &delay, 't');
if (next == NULL || *next != ',')
break;
p->bends[i].start = time += delay;
p->bends[i].cents = strtod(next + 1, (char **)&next);
if (p->bends[i].cents == 0 || *next != ',')
break;
next = lsx_parsesamples(rate, next + 1, &p->bends[i].duration, 't');
if (next == NULL || *next != '\0')
break;
time += p->bends[i].duration;
}
if (i < p->nbends)
return lsx_usage(effp);
return SOX_SUCCESS;
}
static int create(sox_effect_t * effp, int argc, char **argv)
{
priv_t *p = (priv_t *) effp->priv;
char const * opts = "f:o:";
int c;
lsx_getopt_t optstate;
lsx_getopt_init(argc, argv, opts, NULL, lsx_getopt_flag_none, 1, &optstate);
p->frame_rate = 25;
p->ovsamp = 16;
while ((c = lsx_getopt(&optstate)) != -1) switch (c) {
GETOPT_NUMERIC(optstate, 'f', frame_rate, 10 , 80)
GETOPT_NUMERIC(optstate, 'o', ovsamp, 4 , 32)
default: lsx_fail("unknown option `-%c'", optstate.opt); return lsx_usage(effp);
}
argc -= optstate.ind, argv += optstate.ind;
p->bends = lsx_calloc(p->nbends = argc, sizeof(*p->bends));
return parse(effp, argv, 0.); /* No rate yet; parse with dummy */
}
static int start(sox_effect_t * effp)
{
priv_t *p = (priv_t *) effp->priv;
unsigned i;
int n = effp->in_signal.rate / p->frame_rate + .5;
for (p->fftFrameSize = 2; n > 2; p->fftFrameSize <<= 1, n >>= 1);
assert(p->fftFrameSize <= MAX_FRAME_LENGTH);
p->shift = 1;
parse(effp, 0, effp->in_signal.rate); /* Re-parse now rate is known */
p->in_pos = p->bends_pos = 0;
for (i = 0; i < p->nbends; ++i)
if (p->bends[i].duration)
return SOX_SUCCESS;
return SOX_EFF_NULL;
}
static int flow(sox_effect_t * effp, const sox_sample_t * ibuf,
sox_sample_t * obuf, size_t * isamp, size_t * osamp)
{
priv_t *p = (priv_t *) effp->priv;
size_t i, len = *isamp = *osamp = min(*isamp, *osamp);
double magn, phase, tmp, window, real, imag;
double freqPerBin, expct;
long k, qpd, index, inFifoLatency, stepSize, fftFrameSize2;
float pitchShift = p->shift;
/* set up some handy variables */
fftFrameSize2 = p->fftFrameSize / 2;
stepSize = p->fftFrameSize / p->ovsamp;
freqPerBin = effp->in_signal.rate / p->fftFrameSize;
expct = 2. * M_PI * (double) stepSize / (double) p->fftFrameSize;
inFifoLatency = p->fftFrameSize - stepSize;
if (!p->gRover)
p->gRover = inFifoLatency;
/* main processing loop */
for (i = 0; i < len; i++) {
SOX_SAMPLE_LOCALS;
++p->in_pos;
/* As long as we have not yet collected enough data just read in */
p->gInFIFO[p->gRover] = SOX_SAMPLE_TO_FLOAT_32BIT(ibuf[i], effp->clips);
obuf[i] = SOX_FLOAT_32BIT_TO_SAMPLE(
p->gOutFIFO[p->gRover - inFifoLatency], effp->clips);
p->gRover++;
/* now we have enough data for processing */
if (p->gRover >= p->fftFrameSize) {
if (p->bends_pos != p->nbends && p->in_pos >=
p->bends[p->bends_pos].start + p->bends[p->bends_pos].duration) {
pitchShift = p->shift *= pow(2., p->bends[p->bends_pos].cents / 1200);
++p->bends_pos;
}
if (p->bends_pos != p->nbends && p->in_pos >= p->bends[p->bends_pos].start) {
double progress = (double)(p->in_pos - p->bends[p->bends_pos].start) /
p->bends[p->bends_pos].duration;
progress = 1 - cos(M_PI * progress);
progress *= p->bends[p->bends_pos].cents * (.5 / 1200);
pitchShift = p->shift * pow(2., progress);
}
p->gRover = inFifoLatency;
/* do windowing and re,im interleave */
for (k = 0; k < p->fftFrameSize; k++) {
window = -.5 * cos(2 * M_PI * k / (double) p->fftFrameSize) + .5;
p->gFFTworksp[2 * k] = p->gInFIFO[k] * window;
p->gFFTworksp[2 * k + 1] = 0.;
}
/* ***************** ANALYSIS ******************* */
lsx_safe_cdft(2 * p->fftFrameSize, 1, p->gFFTworksp);
/* this is the analysis step */
for (k = 0; k <= fftFrameSize2; k++) {
/* de-interlace FFT buffer */
real = p->gFFTworksp[2 * k];
imag = - p->gFFTworksp[2 * k + 1];
/* compute magnitude and phase */
magn = 2. * sqrt(real * real + imag * imag);
phase = atan2(imag, real);
/* compute phase difference */
tmp = phase - p->gLastPhase[k];
p->gLastPhase[k] = phase;
tmp -= (double) k *expct; /* subtract expected phase difference */
/* map delta phase into +/- Pi interval */
qpd = tmp / M_PI;
if (qpd >= 0)
qpd += qpd & 1;
else qpd -= qpd & 1;
tmp -= M_PI * (double) qpd;
/* get deviation from bin frequency from the +/- Pi interval */
tmp = p->ovsamp * tmp / (2. * M_PI);
/* compute the k-th partials' true frequency */
tmp = (double) k *freqPerBin + tmp * freqPerBin;
/* store magnitude and true frequency in analysis arrays */
p->gAnaMagn[k] = magn;
p->gAnaFreq[k] = tmp;
}
/* this does the actual pitch shifting */
memset(p->gSynMagn, 0, p->fftFrameSize * sizeof(float));
memset(p->gSynFreq, 0, p->fftFrameSize * sizeof(float));
for (k = 0; k <= fftFrameSize2; k++) {
index = k * pitchShift;
if (index <= fftFrameSize2) {
p->gSynMagn[index] += p->gAnaMagn[k];
p->gSynFreq[index] = p->gAnaFreq[k] * pitchShift;
}
}
for (k = 0; k <= fftFrameSize2; k++) { /* SYNTHESIS */
/* get magnitude and true frequency from synthesis arrays */
magn = p->gSynMagn[k], tmp = p->gSynFreq[k];
tmp -= (double) k *freqPerBin; /* subtract bin mid frequency */
tmp /= freqPerBin; /* get bin deviation from freq deviation */
tmp = 2. * M_PI * tmp / p->ovsamp; /* take p->ovsamp into account */
tmp += (double) k *expct; /* add the overlap phase advance back in */
p->gSumPhase[k] += tmp; /* accumulate delta phase to get bin phase */
phase = p->gSumPhase[k];
/* get real and imag part and re-interleave */
p->gFFTworksp[2 * k] = magn * cos(phase);
p->gFFTworksp[2 * k + 1] = - magn * sin(phase);
}
for (k = p->fftFrameSize + 2; k < 2 * p->fftFrameSize; k++)
p->gFFTworksp[k] = 0.; /* zero negative frequencies */
lsx_safe_cdft(2 * p->fftFrameSize, -1, p->gFFTworksp);
/* do windowing and add to output accumulator */
for (k = 0; k < p->fftFrameSize; k++) {
window =
-.5 * cos(2. * M_PI * (double) k / (double) p->fftFrameSize) + .5;
p->gOutputAccum[k] +=
2. * window * p->gFFTworksp[2 * k] / (fftFrameSize2 * p->ovsamp);
}
for (k = 0; k < stepSize; k++)
p->gOutFIFO[k] = p->gOutputAccum[k];
memmove(p->gOutputAccum, /* shift accumulator */
p->gOutputAccum + stepSize, p->fftFrameSize * sizeof(float));
for (k = 0; k < inFifoLatency; k++) /* move input FIFO */
p->gInFIFO[k] = p->gInFIFO[k + stepSize];
}
}
return SOX_SUCCESS;
}
static int stop(sox_effect_t * effp)
{
priv_t *p = (priv_t *) effp->priv;
if (p->bends_pos != p->nbends)
lsx_warn("Input audio too short; bends not applied: %u",
p->nbends - p->bends_pos);
return SOX_SUCCESS;
}
static int lsx_kill(sox_effect_t * effp)
{
priv_t *p = (priv_t *) effp->priv;
unsigned i;
for (i = 0; i < p->nbends; ++i)
free(p->bends[i].str);
free(p->bends);
return SOX_SUCCESS;
}
sox_effect_handler_t const *lsx_bend_effect_fn(void)
{
static sox_effect_handler_t handler = {
"bend", "[-f frame-rate(25)] [-o over-sample(16)] {delay,cents,duration}",
0, create, start, flow, 0, stop, lsx_kill, sizeof(priv_t)
};
return &handler;
}