ref: 021c7886e4ecfe58022848aa3f4877e1986e3089
dir: /src/rate.c/
/* Effect: change sample rate Copyright (c) 2008,12 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
*/
/* Inspired by, and builds upon some of the ideas presented in:
* `The Quest For The Perfect Resampler' by Laurent De Soras;
* http://ldesoras.free.fr/doc/articles/resampler-en.pdf */
#ifdef NDEBUG /* Enable assert always. */
#undef NDEBUG /* Must undef above assert.h or other that might include it. */
#endif
#define _GNU_SOURCE
#include "sox_i.h"
#include "fft4g.h"
#include "dft_filter.h"
#include <assert.h>
#include <string.h>
#define calloc lsx_calloc
#define malloc lsx_malloc
#define raw_coef_t double
#if 0 /* For float32 version, as used in foobar */
#define sample_t float
#define num_coefs4 ((num_coefs + 3) & ~3) /* align coefs for SSE */
#define coefs4_check(i) ((i) < num_coefs)
#else
#define sample_t double
#define num_coefs4 num_coefs
#define coefs4_check(i) 1
#endif
#if defined M_PIl
#define hi_prec_clock_t long double /* __float128 is also a (slow) option */
#else
#define hi_prec_clock_t double
#endif
#define coef(coef_p, interp_order, fir_len, phase_num, coef_interp_num, fir_coef_num) coef_p[(fir_len) * ((interp_order) + 1) * (phase_num) + ((interp_order) + 1) * (fir_coef_num) + (interp_order - coef_interp_num)]
static sample_t * prepare_coefs(raw_coef_t const * coefs, int num_coefs,
int num_phases, int interp_order, int multiplier)
{
int i, j, length = num_coefs4 * num_phases;
sample_t * result = malloc(length * (interp_order + 1) * sizeof(*result));
double fm1 = coefs[0], f1 = 0, f2 = 0;
for (i = num_coefs4 - 1; i >= 0; --i)
for (j = num_phases - 1; j >= 0; --j) {
double f0 = fm1, b = 0, c = 0, d = 0; /* = 0 to kill compiler warning */
int pos = i * num_phases + j - 1;
fm1 = coefs4_check(i) && pos > 0 ? coefs[pos - 1] * multiplier : 0;
switch (interp_order) {
case 1: b = f1 - f0; break;
case 2: b = f1 - (.5 * (f2+f0) - f1) - f0; c = .5 * (f2+f0) - f1; break;
case 3: c=.5*(f1+fm1)-f0;d=(1/6.)*(f2-f1+fm1-f0-4*c);b=f1-f0-d-c; break;
default: if (interp_order) assert(0);
}
#define coef_coef(x) \
coef(result, interp_order, num_coefs4, j, x, num_coefs4 - 1 - i)
coef_coef(0) = f0;
if (interp_order > 0) coef_coef(1) = b;
if (interp_order > 1) coef_coef(2) = c;
if (interp_order > 2) coef_coef(3) = d;
#undef coef_coef
f2 = f1, f1 = f0;
}
return result;
}
typedef struct { /* So generated filter coefs may be shared between channels */
sample_t * poly_fir_coefs;
dft_filter_t dft_filter[2];
} rate_shared_t;
struct stage;
typedef void (* stage_fn_t)(struct stage * input, fifo_t * output);
typedef struct stage {
/* Common to all stage types: */
stage_fn_t fn;
fifo_t fifo;
int pre; /* Number of past samples to store */
int pre_post; /* pre + number of future samples to store */
int preload; /* Number of zero samples to pre-load the fifo */
double out_in_ratio; /* For buffer management. */
/* For a stage with variable (run-time generated) filter coefs: */
rate_shared_t * shared;
int dft_filter_num; /* Which, if any, of the 2 DFT filters to use */
/* For a stage with variable L/M: */
union { /* 32bit.32bit fixed point arithmetic */
#if defined(WORDS_BIGENDIAN)
struct {int32_t integer; uint32_t fraction;} parts;
#else
struct {uint32_t fraction; int32_t integer;} parts;
#endif
int64_t all;
#define MULT32 (65536. * 65536.)
hi_prec_clock_t hi_prec_clock;
} at, step;
sox_bool use_hi_prec_clock;
int L, remL, remM;
int n, phase_bits;
} stage_t;
#define stage_occupancy(s) max(0, fifo_occupancy(&(s)->fifo) - (s)->pre_post)
#define stage_read_p(s) ((sample_t *)fifo_read_ptr(&(s)->fifo) + (s)->pre)
static void cubic_stage_fn(stage_t * p, fifo_t * output_fifo)
{
int i, num_in = stage_occupancy(p), max_num_out = 1 + num_in*p->out_in_ratio;
sample_t const * input = stage_read_p(p);
sample_t * output = fifo_reserve(output_fifo, max_num_out);
for (i = 0; p->at.parts.integer < num_in; ++i, p->at.all += p->step.all) {
sample_t const * s = input + p->at.parts.integer;
sample_t x = p->at.parts.fraction * (1 / MULT32);
sample_t b = .5*(s[1]+s[-1])-*s, a = (1/6.)*(s[2]-s[1]+s[-1]-*s-4*b);
sample_t c = s[1]-*s-a-b;
output[i] = ((a*x + b)*x + c)*x + *s;
}
assert(max_num_out - i >= 0);
fifo_trim_by(output_fifo, max_num_out - i);
fifo_read(&p->fifo, p->at.parts.integer, NULL);
p->at.parts.integer = 0;
}
static void dft_stage_fn(stage_t * p, fifo_t * output_fifo)
{
sample_t * output, tmp;
int i, j, num_in = max(0, fifo_occupancy(&p->fifo));
rate_shared_t const * s = p->shared;
dft_filter_t const * f = &s->dft_filter[p->dft_filter_num];
int const overlap = f->num_taps - 1;
while (p->remL + p->L * num_in >= f->dft_length) {
div_t divd = div(f->dft_length - overlap - p->remL + p->L - 1, p->L);
sample_t const * input = fifo_read_ptr(&p->fifo);
fifo_read(&p->fifo, divd.quot, NULL);
num_in -= divd.quot;
output = fifo_reserve(output_fifo, f->dft_length);
if (lsx_is_power_of_2(p->L)) { /* F-domain */
int portion = f->dft_length / p->L;
memcpy(output, input, (unsigned)portion * sizeof(*output));
lsx_safe_rdft(portion, 1, output);
for (i = portion + 2; i < (portion << 1); i += 2)
output[i] = output[(portion << 1) - i],
output[i+1] = -output[(portion << 1) - i + 1];
output[portion] = output[1];
output[portion + 1] = 0;
output[1] = output[0];
for (portion <<= 1; i < f->dft_length; i += portion, portion <<= 1) {
memcpy(output + i, output, portion * sizeof(*output));
output[i + 1] = 0;
}
} else {
if (p->L == 1)
memcpy(output, input, f->dft_length * sizeof(*output));
else {
memset(output, 0, f->dft_length * sizeof(*output));
for (j = 0, i = p->remL; i < f->dft_length; ++j, i += p->L)
output[i] = input[j];
p->remL = p->L - 1 - divd.rem;
}
lsx_safe_rdft(f->dft_length, 1, output);
}
output[0] *= f->coefs[0];
if (p->step.parts.integer > 0) {
output[1] *= f->coefs[1];
for (i = 2; i < f->dft_length; i += 2) {
tmp = output[i];
output[i ] = f->coefs[i ] * tmp - f->coefs[i+1] * output[i+1];
output[i+1] = f->coefs[i+1] * tmp + f->coefs[i ] * output[i+1];
}
lsx_safe_rdft(f->dft_length, -1, output);
if (p->step.parts.integer != 1) {
for (j = 0, i = p->remM; i < f->dft_length - overlap; ++j,
i += p->step.parts.integer)
output[j] = output[i];
p->remM = i - (f->dft_length - overlap);
fifo_trim_by(output_fifo, f->dft_length - j);
}
else fifo_trim_by(output_fifo, overlap);
}
else { /* F-domain */
int m = -p->step.parts.integer;
for (i = 2; i < (f->dft_length >> m); i += 2) {
tmp = output[i];
output[i ] = f->coefs[i ] * tmp - f->coefs[i+1] * output[i+1];
output[i+1] = f->coefs[i+1] * tmp + f->coefs[i ] * output[i+1];
}
output[1] = f->coefs[i] * output[i] - f->coefs[i+1] * output[i+1];
lsx_safe_rdft(f->dft_length >> m, -1, output);
fifo_trim_by(output_fifo, (((1 << m) - 1) * f->dft_length + overlap) >>m);
}
}
}
static void dft_stage_init(
unsigned instance, double Fp, double Fs, double Fn, double att,
double phase, stage_t * stage, int L, int M)
{
dft_filter_t * f = &stage->shared->dft_filter[instance];
if (!f->num_taps) {
int num_taps = 0, dft_length, i;
int k = phase == 50 && lsx_is_power_of_2(L) && Fn == L? L << 1 : 4;
double * h = lsx_design_lpf(Fp, Fs, Fn, att, &num_taps, -k, -1.);
if (phase != 50)
lsx_fir_to_phase(&h, &num_taps, &f->post_peak, phase);
else f->post_peak = num_taps / 2;
dft_length = lsx_set_dft_length(num_taps);
f->coefs = calloc(dft_length, sizeof(*f->coefs));
for (i = 0; i < num_taps; ++i)
f->coefs[(i + dft_length - num_taps + 1) & (dft_length - 1)]
= h[i] / dft_length * 2 * L;
free(h);
f->num_taps = num_taps;
f->dft_length = dft_length;
lsx_safe_rdft(dft_length, 1, f->coefs);
lsx_debug("fir_len=%i dft_length=%i Fp=%g Fs=%g Fn=%g att=%g %i/%i",
num_taps, dft_length, Fp, Fs, Fn, att, L, M);
}
stage->fn = dft_stage_fn;
stage->preload = f->post_peak / L;
stage->remL = f->post_peak % L;
stage->L = L;
stage->step.parts.integer = abs(3-M) == 1 && Fs == 1? -M/2 : M;
stage->dft_filter_num = instance;
}
#include "rate_filters.h"
typedef struct {
double factor;
uint64_t samples_in, samples_out;
int num_stages;
stage_t * stages;
} rate_t;
#define pre_stage p->stages[shift]
#define arb_stage p->stages[shift + have_pre_stage]
#define post_stage p->stages[shift + have_pre_stage + have_arb_stage]
#define have_pre_stage (preM * preL != 1)
#define have_arb_stage (arbM * arbL != 1)
#define have_post_stage (postM * postL != 1)
#define TO_3dB(a) ((1.6e-6*a-7.5e-4)*a+.646)
#define LOW_Q_BW0_PC (67 + 5 / 8.)
typedef enum {
rolloff_none, rolloff_small /* <= 0.01 dB */, rolloff_medium /* <= 0.35 dB */
} rolloff_t;
static void rate_init(
/* Private work areas (to be supplied by the client): */
rate_t * p, /* Per audio channel. */
rate_shared_t * shared, /* Between channels (undergoing same rate change)*/
/* Public parameters: Typically */
double factor, /* Input rate divided by output rate. */
double bits, /* Required bit-accuracy (pass + stop) 16|20|28 */
double phase, /* Linear/minimum etc. filter phase. 50 */
double bw_pc, /* Pass-band % (0dB pt.) to preserve. 91.3|98.4*/
double anti_aliasing_pc, /* % bandwidth without aliasing 100 */
rolloff_t rolloff, /* Pass-band roll-off small */
sox_bool maintain_3dB_pt, /* true */
/* Primarily for test/development purposes: */
sox_bool use_hi_prec_clock,/* Increase irrational ratio accuracy. false */
int interpolator, /* Force a particular coef interpolator. -1 */
int max_coefs_size, /* k bytes of coefs to try to keep below. 400 */
sox_bool noSmallIntOpt) /* Disable small integer optimisations. false */
{
double att = (bits + 1) * linear_to_dB(2.), attArb = att; /* pass + stop */
double tbw0 = 1 - bw_pc / 100, Fs_a = 2 - anti_aliasing_pc / 100;
double arbM = factor, tbw_tighten = 1;
int n = 0, i, preL = 1, preM = 1, shift = 0, arbL = 1, postL = 1, postM = 1;
sox_bool upsample = sox_false, rational = sox_false, iOpt = !noSmallIntOpt;
int mode = rolloff > rolloff_small? factor > 1 || bw_pc > LOW_Q_BW0_PC :
ceil(2 + (bits - 17) / 4);
stage_t * s;
assert(factor > 0);
assert(!bits || (15 <= bits && bits <= 33));
assert(0 <= phase && phase <= 100);
assert(53 <= bw_pc && bw_pc <= 100);
assert(85 <= anti_aliasing_pc && anti_aliasing_pc <= 100);
p->factor = factor;
if (bits) while (!n++) { /* Determine stages: */
int try, L, M, x, maxL = interpolator > 0? 1 : mode? 2048 :
ceil(max_coefs_size * 1000. / (U100_l * sizeof(sample_t)));
double d, epsilon = 0, frac;
upsample = arbM < 1;
for (i = arbM * .5, shift = 0; i >>= 1; arbM *= .5, ++shift);
preM = upsample || (arbM > 1.5 && arbM < 2);
postM = 1 + (arbM > 1 && preM), arbM /= postM;
preL = 1 + (!preM && arbM < 2) + (upsample && mode), arbM *= preL;
if ((frac = arbM - (int)arbM))
epsilon = fabs((uint32_t)(frac * MULT32 + .5) / (frac * MULT32) - 1);
for (i = 1, rational = !frac; i <= maxL && !rational; ++i) {
d = frac * i, try = d + .5;
if ((rational = fabs(try / d - 1) <= epsilon)) { /* No long doubles! */
if (try == i)
arbM = ceil(arbM), shift += arbM > 2, arbM /= 1 + (arbM > 2);
else arbM = i * (int)arbM + try, arbL = i;
}
}
L = preL * arbL, M = arbM * postM, x = (L|M)&1, L >>= !x, M >>= !x;
if (iOpt && postL == 1 && (d = preL * arbL / arbM) > 4 && d != 5) {
for (postL = 4, i = d / 16; i >>= 1; postL <<= 1);
arbM = arbM * postL / arbL / preL, arbL = 1, n = 0;
} else if (rational && (max(L, M) < 3 + 2 * iOpt || L * M < 6 * iOpt))
preL = L, preM = M, arbM = arbL = postM = 1;
if (!mode && (!rational || !n))
++mode, n = 0;
}
p->num_stages = shift + have_pre_stage + have_arb_stage + have_post_stage;
if (!p->num_stages)
return;
p->stages = calloc(p->num_stages + 1, sizeof(*p->stages));
for (i = 0; i < p->num_stages; ++i)
p->stages[i].shared = shared;
if ((n = p->num_stages) > 1) { /* Att. budget: */
if (have_arb_stage)
att += linear_to_dB(2.), attArb = att, --n;
att += linear_to_dB((double)n);
}
for (n = 0; n + 1u < array_length(half_firs) && att > half_firs[n].att; ++n);
for (i = 0, s = p->stages; i < shift; ++i, ++s) {
s->fn = half_firs[n].fn;
s->pre_post = 4 * half_firs[n].num_coefs;
s->preload = s->pre = s->pre_post >> 1;
}
if (have_pre_stage) {
if (maintain_3dB_pt && have_post_stage) { /* Trans. bands overlapping. */
double tbw3 = tbw0 * TO_3dB(att); /* TODO: consider Fs_a. */
double x = ((2.1429e-4 - 5.2083e-7 * att) * att - .015863) * att + 3.95;
x = att * pow((tbw0 - tbw3) / (postM / (factor * postL) - 1 + tbw0), x);
if (x > .035) {
tbw_tighten = ((4.3074e-3 - 3.9121e-4 * x) * x - .040009) * x + 1.0014;
lsx_debug("x=%g tbw_tighten=%g", x, tbw_tighten);
}
}
dft_stage_init(0, 1 - tbw0 * tbw_tighten, Fs_a, preM? max(preL, preM) :
arbM / arbL, att, phase, &pre_stage, preL, max(preM, 1));
}
if (!bits) { /* Quick and dirty arb stage: */
arb_stage.fn = cubic_stage_fn;
arb_stage.step.all = arbM * MULT32 + .5;
arb_stage.pre_post = max(3, arb_stage.step.parts.integer);
arb_stage.preload = arb_stage.pre = 1;
arb_stage.out_in_ratio = MULT32 * arbL / arb_stage.step.all;
}
else if (have_arb_stage) { /* Higher quality arb stage: */
poly_fir_t const * f = &poly_firs[6*(upsample + !!preM) + mode - !upsample];
int order, num_coefs = f->interp[0].scalar, phase_bits, phases, coefs_size;
double x = .5, at, Fp, Fs, Fn, mult = upsample? 1 : arbL / arbM;
poly_fir1_t const * f1;
Fn = !upsample && preM? x = arbM / arbL : 1;
Fp = !preM? mult : mode? .5 : 1;
Fs = 2 - Fp; /* Ignore Fs_a; it would have little benefit here. */
Fp *= 1 - tbw0;
if (rolloff > rolloff_small && mode)
Fp = !preM? mult * .5 - .125 : mult * .05 + .1;
else if (rolloff == rolloff_small)
Fp = Fs - (Fs - .148 * x - Fp * .852) * (.00813 * bits + .973);
i = (interpolator < 0? !rational : max(interpolator, !rational)) - 1;
do {
f1 = &f->interp[++i];
assert(f1->fn);
if (i)
arbM /= arbL, arbL = 1, rational = sox_false;
phase_bits = ceil(f1->scalar + log(mult)/log(2.));
phases = !rational? (1 << phase_bits) : arbL;
if (!f->interp[0].scalar) {
int phases0 = max(phases, 19), n0 = 0;
lsx_design_lpf(Fp, Fs, -Fn, attArb, &n0, phases0, f->beta);
num_coefs = n0 / phases0 + 1, num_coefs += num_coefs & !preM;
}
if ((num_coefs & 1) && rational && (arbL & 1))
phases <<= 1, arbL <<= 1, arbM *= 2;
at = arbL * .5 * (num_coefs & 1);
order = i + (i && mode > 4);
coefs_size = num_coefs4 * phases * (order + 1) * sizeof(sample_t);
} while (interpolator < 0 && i < 2 && f->interp[i+1].fn &&
coefs_size / 1000 > max_coefs_size);
if (!arb_stage.shared->poly_fir_coefs) {
int num_taps = num_coefs * phases - 1;
raw_coef_t * coefs = lsx_design_lpf(
Fp, Fs, Fn, attArb, &num_taps, phases, f->beta);
arb_stage.shared->poly_fir_coefs = prepare_coefs(
coefs, num_coefs, phases, order, 1);
lsx_debug("fir_len=%i phases=%i coef_interp=%i size=%s",
num_coefs, phases, order, lsx_sigfigs3((double)coefs_size));
free(coefs);
}
arb_stage.fn = f1->fn;
arb_stage.pre_post = num_coefs4 - 1;
arb_stage.preload = (num_coefs - 1) >> 1;
arb_stage.n = num_coefs4;
arb_stage.phase_bits = phase_bits;
arb_stage.L = arbL;
arb_stage.use_hi_prec_clock = mode > 1 && use_hi_prec_clock && !rational;
if (arb_stage.use_hi_prec_clock) {
arb_stage.at.hi_prec_clock = at;
arb_stage.step.hi_prec_clock = arbM;
arb_stage.out_in_ratio = arbL / arb_stage.step.hi_prec_clock;
} else {
arb_stage.at.all = at * MULT32 + .5;
arb_stage.step.all = arbM * MULT32 + .5;
arb_stage.out_in_ratio = MULT32 * arbL / arb_stage.step.all;
}
}
if (have_post_stage)
dft_stage_init(1, 1 - (1 - (1 - tbw0) *
(upsample? factor * postL / postM : 1)) * tbw_tighten, Fs_a,
(double)max(postL, postM), att, phase, &post_stage, postL, postM);
for (i = 0, s = p->stages; i < p->num_stages; ++i, ++s) {
fifo_create(&s->fifo, (int)sizeof(sample_t));
memset(fifo_reserve(&s->fifo, s->preload), 0, sizeof(sample_t)*s->preload);
lsx_debug("%5i|%-5i preload=%i remL=%i",
s->pre, s->pre_post - s->pre, s->preload, s->remL);
}
fifo_create(&s->fifo, (int)sizeof(sample_t));
}
static void rate_process(rate_t * p)
{
stage_t * stage = p->stages;
int i;
for (i = 0; i < p->num_stages; ++i, ++stage)
stage->fn(stage, &(stage+1)->fifo);
}
static sample_t * rate_input(rate_t * p, sample_t const * samples, size_t n)
{
p->samples_in += n;
return fifo_write(&p->stages[0].fifo, (int)n, samples);
}
static sample_t const * rate_output(rate_t * p, sample_t * samples, size_t * n)
{
fifo_t * fifo = &p->stages[p->num_stages].fifo;
p->samples_out += *n = min(*n, (size_t)fifo_occupancy(fifo));
return fifo_read(fifo, (int)*n, samples);
}
static void rate_flush(rate_t * p)
{
fifo_t * fifo = &p->stages[p->num_stages].fifo;
uint64_t samples_out = p->samples_in / p->factor + .5;
size_t remaining = samples_out > p->samples_out ?
(size_t)(samples_out - p->samples_out) : 0;
sample_t * buff = calloc(1024, sizeof(*buff));
if (remaining > 0) {
while ((size_t)fifo_occupancy(fifo) < remaining) {
rate_input(p, buff, (size_t) 1024);
rate_process(p);
}
fifo_trim_to(fifo, (int)remaining);
p->samples_in = 0;
}
free(buff);
}
static void rate_close(rate_t * p)
{
rate_shared_t *shared;
int i;
if (!p->num_stages)
return;
shared = p->stages[0].shared;
for (i = 0; i <= p->num_stages; ++i)
fifo_delete(&p->stages[i].fifo);
free(shared->dft_filter[0].coefs);
free(shared->dft_filter[1].coefs);
free(shared->poly_fir_coefs);
memset(shared, 0, sizeof(*shared));
free(p->stages);
}
/*------------------------------- SoX Wrapper --------------------------------*/
typedef struct {
sox_rate_t out_rate;
int rolloff, coef_interp, max_coefs_size;
double bit_depth, phase, bw_0dB_pc, anti_aliasing_pc;
sox_bool use_hi_prec_clock, noIOpt, given_0dB_pt;
rate_t rate;
rate_shared_t shared, * shared_ptr;
} priv_t;
static int create(sox_effect_t * effp, int argc, char **argv)
{
priv_t * p = (priv_t *) effp->priv;
int c, quality;
char * dummy_p, * found_at;
char const * opts = "+i:c:b:B:A:p:Q:R:d:MILafnost" "qlmghevu";
char const * qopts = strchr(opts, 'q');
double rej = 0, bw_3dB_pc = 0;
sox_bool allow_aliasing = sox_false;
lsx_getopt_t optstate;
lsx_getopt_init(argc, argv, opts, NULL, lsx_getopt_flag_none, 1, &optstate);
p->coef_interp = quality = -1;
p->rolloff = rolloff_small;
p->phase = 50;
p->max_coefs_size = 400;
p->shared_ptr = &p->shared;
while ((c = lsx_getopt(&optstate)) != -1) switch (c) {
GETOPT_NUMERIC(optstate, 'i', coef_interp, -1, 2)
GETOPT_NUMERIC(optstate, 'c', max_coefs_size, 100, INT_MAX)
GETOPT_NUMERIC(optstate, 'p', phase, 0, 100)
GETOPT_NUMERIC(optstate, 'B', bw_0dB_pc, 53, 99.5)
GETOPT_NUMERIC(optstate, 'A', anti_aliasing_pc, 85, 100)
GETOPT_NUMERIC(optstate, 'd', bit_depth, 15, 33)
GETOPT_LOCAL_NUMERIC(optstate, 'b', bw_3dB_pc, 74, 99.7)
GETOPT_LOCAL_NUMERIC(optstate, 'R', rej, 90, 200)
GETOPT_LOCAL_NUMERIC(optstate, 'Q', quality, 0, 7)
case 'M': p->phase = 0; break;
case 'I': p->phase = 25; break;
case 'L': p->phase = 50; break;
case 'a': allow_aliasing = sox_true; break;
case 'f': p->rolloff = rolloff_none; break;
case 'n': p->noIOpt = sox_true; break;
case 's': bw_3dB_pc = 99; break;
case 't': p->use_hi_prec_clock = sox_true; break;
default:
if ((found_at = strchr(qopts, c)))
quality = found_at - qopts;
else {
lsx_fail("unknown option `-%c'", optstate.opt);
return lsx_usage(effp);
}
}
argc -= optstate.ind, argv += optstate.ind;
if ((unsigned)quality < 2 && (p->bw_0dB_pc || bw_3dB_pc || p->phase != 50 ||
allow_aliasing || rej || p->bit_depth || p->anti_aliasing_pc)) {
lsx_fail("override options not allowed with this quality level");
return SOX_EOF;
}
if (quality < 0 && rej == 0 && p->bit_depth == 0)
quality = 4;
if (rej)
p->bit_depth = rej / linear_to_dB(2.);
else {
if (quality >= 0) {
p->bit_depth = quality? 16 + 4 * max(quality - 3, 0) : 0;
if (quality <= 2)
p->rolloff = rolloff_medium;
}
rej = p->bit_depth * linear_to_dB(2.);
}
if (bw_3dB_pc && p->bw_0dB_pc) {
lsx_fail("conflicting bandwidth options");
return SOX_EOF;
}
allow_aliasing |= p->anti_aliasing_pc != 0;
if (!bw_3dB_pc && !p->bw_0dB_pc)
p->bw_0dB_pc = quality == 1? LOW_Q_BW0_PC : 100 - 5 / TO_3dB(rej);
else if (bw_3dB_pc && bw_3dB_pc < 85 && allow_aliasing) {
lsx_fail("minimum allowed 3dB bandwidth with aliasing is %g%%", 85.);
return SOX_EOF;
}
else if (p->bw_0dB_pc && p->bw_0dB_pc < 74 && allow_aliasing) {
lsx_fail("minimum allowed bandwidth with aliasing is %g%%", 74.);
return SOX_EOF;
}
if (bw_3dB_pc)
p->bw_0dB_pc = 100 - (100 - bw_3dB_pc) / TO_3dB(rej);
else {
bw_3dB_pc = 100 - (100 - p->bw_0dB_pc) * TO_3dB(rej);
p->given_0dB_pt = sox_true;
}
p->anti_aliasing_pc = p->anti_aliasing_pc? p->anti_aliasing_pc :
allow_aliasing? bw_3dB_pc : 100;
if (argc) {
if ((p->out_rate = lsx_parse_frequency(*argv, &dummy_p)) <= 0 || *dummy_p)
return lsx_usage(effp);
argc--; argv++;
effp->out_signal.rate = p->out_rate;
}
return argc? lsx_usage(effp) : SOX_SUCCESS;
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *) effp->priv;
double out_rate = p->out_rate != 0 ? p->out_rate : effp->out_signal.rate;
if (effp->in_signal.rate == out_rate)
return SOX_EFF_NULL;
if (effp->in_signal.mult)
*effp->in_signal.mult *= .705; /* 1/(2/sinc(pi/3)-1); see De Soras 4.1.2 */
effp->out_signal.channels = effp->in_signal.channels;
effp->out_signal.rate = out_rate;
rate_init(&p->rate, p->shared_ptr, effp->in_signal.rate/out_rate,p->bit_depth,
p->phase, p->bw_0dB_pc, p->anti_aliasing_pc, p->rolloff, !p->given_0dB_pt,
p->use_hi_prec_clock, p->coef_interp, p->max_coefs_size, p->noIOpt);
if (!p->rate.num_stages) {
lsx_warn("input and output rates too close, skipping resampling");
return SOX_EFF_NULL;
}
return SOX_SUCCESS;
}
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 odone = *osamp;
sample_t const * s = rate_output(&p->rate, NULL, &odone);
lsx_save_samples(obuf, s, odone, &effp->clips);
if (*isamp && odone < *osamp) {
sample_t * t = rate_input(&p->rate, NULL, *isamp);
lsx_load_samples(t, ibuf, *isamp);
rate_process(&p->rate);
}
else *isamp = 0;
*osamp = odone;
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
static size_t isamp = 0;
rate_flush(&p->rate);
return flow(effp, 0, obuf, &isamp, osamp);
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *) effp->priv;
rate_close(&p->rate);
return SOX_SUCCESS;
}
sox_effect_handler_t const * lsx_rate_effect_fn(void)
{
static sox_effect_handler_t handler = {
"rate", 0, SOX_EFF_RATE, create, start, flow, drain, stop, 0, sizeof(priv_t)
};
static char const * lines[] = {
"[-q|-l|-m|-h|-v] [override-options] RATE[k]",
" BAND-",
" QUALITY WIDTH REJ dB TYPICAL USE",
" -q quick n/a ~30 @ Fs/4 playback on ancient hardware",
" -l low 80% 100 playback on old hardware",
" -m medium 95% 100 audio playback",
" -h high (default) 95% 125 16-bit mastering (use with dither)",
" -v very high 95% 175 24-bit mastering",
" OVERRIDE OPTIONS (only with -m, -h, -v)",
" -M/-I/-L Phase response = minimum/intermediate/linear(default)",
" -s Steep filter (band-width = 99%)",
" -a Allow aliasing above the pass-band",
" -b 74-99.7 Any band-width %",
" -p 0-100 Any phase response (0 = minimum, 25 = intermediate,",
" 50 = linear, 100 = maximum)",
};
static char * usage;
handler.usage = lsx_usage_lines(&usage, lines, array_length(lines));
return &handler;
}