boo/soxr/src/vr32.c

658 lines
21 KiB
C

/* SoX Resampler Library Copyright (c) 2007-13 robs@users.sourceforge.net
* Licence for this file: LGPL v2.1 See LICENCE for details. */
/* Variable-rate resampling. */
#include <assert.h>
#include <math.h>
#if !defined M_PI
#define M_PI 3.14159265358979323846
#endif
#if !defined M_LN2
#define M_LN2 0.69314718055994530942
#endif
#include <string.h>
#include <stdlib.h>
#include "internal.h"
#define FIFO_SIZE_T int
#define FIFO_MIN 0x8000
#include "fifo.h"
#include "vr-coefs.h"
#define FADE_LEN_BITS 9
#define PHASE_BITS_D 10
#define PHASE_BITS_U 9
#define PHASES0_D 12
#define POLY_FIR_LEN_D 20
#define PHASES0_U 6
#define POLY_FIR_LEN_U 12
#define MULT32 (65536. * 65536.)
#define PHASES_D (1 << PHASE_BITS_D)
#define PHASES_U (1 << PHASE_BITS_U)
#define CONVOLVE \
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
#define HALF_FIR_LEN_2 (iAL(half_fir_coefs) - 1)
#define HALF_FIR_LEN_4 (HALF_FIR_LEN_2 / 2)
#define _ sum += (input[-i] + input[i]) * half_fir_coefs[i], ++i;
static float half_fir(float const * input)
{
long i = 1;
float sum = input[0] * half_fir_coefs[0];
CONVOLVE CONVOLVE
assert(i == HALF_FIR_LEN_2 + 1);
return (float)sum;
}
#undef _
#define _ sum += (input[-i] + input[i]) * half_fir_coefs[2*i], ++i;
static float double_fir0(float const * input)
{
int i = 1;
float sum = input[0] * half_fir_coefs[0];
CONVOLVE
assert(i == HALF_FIR_LEN_4 + 1);
return (float)(sum * 2);
}
#undef _
#define _ sum += (input[-i] + input[1+i]) * half_fir_coefs[2*i+1], ++i;
static float double_fir1(float const * input)
{
int i = 0;
float sum = 0;
CONVOLVE
assert(i == HALF_FIR_LEN_4 + 0);
return (float)(sum * 2);
}
#undef _
static float fast_half_fir(float const * input)
{
int i = 0;
float sum = input[0] * .5f;
#define _ sum += (input[-(2*i+1)] + input[2*i+1]) * fast_half_fir_coefs[i], ++i;
_ _ _ _ _ _
#undef _
return (float)sum;
}
#define IIR_FILTER _ _ _ _ _ _ _
#define _ in1=(in1-p->y[i])*iir_coefs[i]+tmp1;tmp1=p->y[i],p->y[i]=in1;++i;\
in0=(in0-p->y[i])*iir_coefs[i]+tmp0;tmp0=p->y[i],p->y[i]=in0;++i;
typedef struct {float x[2], y[AL(iir_coefs)];} half_iir_t;
static float half_iir1(half_iir_t * p, float in0, float in1)
{
int i = 0;
float tmp0, tmp1;
tmp0 = p->x[0], p->x[0] = in0;
tmp1 = p->x[1], p->x[1] = in1;
IIR_FILTER
p->y[i] = in1 = (in1 - p->y[i]) * iir_coefs[i] + tmp1;
return in1 + in0;
}
#undef _
static void half_iir(half_iir_t * p, float * obuf, float const * ibuf, int olen)
{
int i;
for (i=0; i < olen; obuf[i] = (float)half_iir1(p, ibuf[i*2], ibuf[i*2+1]),++i);
}
static void half_phase(half_iir_t * p, float * buf, int len)
{
float const small_normal = 1/MULT32/MULT32; /* To quash denormals on path 0.*/
int i;
for (i = 0; i < len; buf[i] = (float)half_iir1(p, buf[i], 0), ++i);
#define _ p->y[i] += small_normal, i += 2;
i = 0, _ IIR_FILTER
#undef _
#define _ p->y[i] -= small_normal, i += 2;
i = 0, _ IIR_FILTER
#undef _
}
#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)]
#define COEF(h,l,i) ((i)<0||(i)>=(l)?0:(h)[(i)>(l)/2?(l)-(i):(i)])
static void prepare_coefs(float * coefs, int n, int phases0, int phases,
float const * coefs0, double multiplier)
{
double k[6];
int length0 = n * phases0, length = n * phases, K0 = iAL(k)/2 - 1, i, j, pos;
float * coefs1 = malloc(((size_t)length / 2 + 1) * sizeof(*coefs1));
float * p = coefs1, f0, f1 = 0;
for (j = 0; j < iAL(k); k[j] = COEF(coefs0, length0, j - K0), ++j);
for (pos = i = 0; i < length0 / 2; ++i) {
double b=(1/24.)*(k[0]+k[4]+6*k[2]-4*(k[1]+k[3])),d=.5*(k[1]+k[3])-k[2]-b;
double a=(1/120.)*(k[5]-k[2]-9*(9*b+d)+2.5*(k[3]-k[1])-2*(k[4]-k[0]));
double c=(1/12.)*(k[4]-k[0]-2*(k[3]-k[1])-60*a),e=.5*(k[3]-k[1])-a-c;
for (; pos / phases == i; pos += phases0) {
double x = (double)(pos % phases) / phases;
*p++ = (float)(k[K0] + ((((a*x + b)*x + c)*x + d)*x + e)*x);
}
for (j = 0; j < iAL(k) - 1; k[j] = k[j + 1], ++j);
k[j] = COEF(coefs0, length0, i + iAL(k) / 2 + 1);
}
if (!(length & 1))
*p++ = (float)k[K0];
assert(p - coefs1 == length / 2 + 1);
for (i = 0; i < n; ++i) for (j = phases - 1; j >= 0; --j, f1 = f0) {
pos = (n - 1 - i) * phases + j;
f0 = COEF(coefs1, length, pos) * (float)multiplier;
coef(coefs, 1, n, j, 0, i) = (float)f0;
coef(coefs, 1, n, j, 1, i) = (float)(f1 - f0);
}
free(coefs1);
}
#define _ sum += (b *x + a)*input[i], ++i;
#define a (coef(poly_fir_coefs_d, 1, POLY_FIR_LEN_D, phase, 0,i))
#define b (coef(poly_fir_coefs_d, 1, POLY_FIR_LEN_D, phase, 1,i))
static float poly_fir_coefs_d[POLY_FIR_LEN_D * PHASES_D * 2];
static float poly_fir1_d(float const * input, uint32_t frac)
{
int i = 0, phase = (int)(frac >> (32 - PHASE_BITS_D));
float sum = 0, x = (float)(frac << PHASE_BITS_D) * (float)(1 / MULT32);
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
assert(i == POLY_FIR_LEN_D);
return (float)sum;
}
#undef a
#undef b
#define a (coef(poly_fir_coefs_u, 1, POLY_FIR_LEN_U, phase, 0,i))
#define b (coef(poly_fir_coefs_u, 1, POLY_FIR_LEN_U, phase, 1,i))
static float poly_fir_coefs_u[POLY_FIR_LEN_U * PHASES_U * 2];
static float poly_fir1_u(float const * input, uint32_t frac)
{
int i = 0, phase = (int)(frac >> (32 - PHASE_BITS_U));
float sum = 0, x = (float)(frac << PHASE_BITS_U) * (float)(1 / MULT32);
_ _ _ _ _ _ _ _ _ _ _ _
assert(i == POLY_FIR_LEN_U);
return (float)sum;
}
#undef a
#undef b
#undef _
#define ADD_TO(x,y) x.all += y.all
#define SUBTRACT_FROM(x,y) x.all -= y.all
#define FRAC(x) x.part.frac
#define INT(x) x.part.integer
typedef struct {
union {
int64_t all;
#if WORDS_BIGENDIAN
struct {int32_t integer; uint32_t frac;} part;
#else
struct {uint32_t frac; int32_t integer;} part;
#endif
} at, step, step_step;
float const * input;
int len, stage_num;
bool is_d; /* true: downsampling at x2 rate; false: upsampling at 1x rate. */
double step_mult;
} stream_t;
static int poly_fir_d(stream_t * s, float * output, int olen)
{
int i;
float const * input = s->input - POLY_FIR_LEN_D / 2 + 1;
for (i = 0; i < olen && INT(s->at) < s->len; ++i) {
output[i] = poly_fir1_d(input + INT(s->at), FRAC(s->at));
ADD_TO(s->at, s->step);
if (!(INT(s->at) < s->len)) {
SUBTRACT_FROM(s->at, s->step);
break;
}
output[++i] = poly_fir1_d(input + INT(s->at), FRAC(s->at));
ADD_TO(s->at, s->step);
ADD_TO(s->step, s->step_step);
}
return i;
}
static int poly_fir_fade_d(
stream_t * s, float const * vol, int step, float * output, int olen)
{
int i;
float const * input = s->input - POLY_FIR_LEN_D / 2 + 1;
for (i = 0; i < olen && INT(s->at) < s->len; ++i, vol += step) {
output[i] += *vol * poly_fir1_d(input + INT(s->at), FRAC(s->at));
ADD_TO(s->at, s->step);
if (!(INT(s->at) < s->len)) {
SUBTRACT_FROM(s->at, s->step);
break;
}
output[++i] += *(vol += step) * poly_fir1_d(input + INT(s->at),FRAC(s->at));
ADD_TO(s->at, s->step);
ADD_TO(s->step, s->step_step);
}
return i;
}
static int poly_fir_u(stream_t * s, float * output, int olen)
{
int i;
float const * input = s->input - POLY_FIR_LEN_U / 2 + 1;
for (i = 0; i < olen && INT(s->at) < s->len; ++i) {
output[i] = poly_fir1_u(input + INT(s->at), FRAC(s->at));
ADD_TO(s->at, s->step);
ADD_TO(s->step, s->step_step);
}
return i;
}
static int poly_fir_fade_u(
stream_t * s, float const * vol, int step, float * output, int olen)
{
int i;
float const * input = s->input - POLY_FIR_LEN_U / 2 + 1;
for (i = 0; i < olen && INT(s->at) < s->len; i += 2, vol += step) {
output[i] += *vol * poly_fir1_u(input + INT(s->at), FRAC(s->at));
ADD_TO(s->at, s->step);
ADD_TO(s->step, s->step_step);
}
return i;
}
#define shiftr(x,by) ((by) < 0? (x) << (-(by)) : (x) >> (by))
#define shiftl(x,by) shiftr(x,-(by))
#define stage_occupancy(s) (fifo_occupancy(&(s)->fifo) - 4*HALF_FIR_LEN_2)
#define stage_read_p(s) ((float *)fifo_read_ptr(&(s)->fifo) + 2*HALF_FIR_LEN_2)
#define stage_preload(s) memset(fifo_reserve(&(s)->fifo, (s)->preload), \
0, sizeof(float) * (size_t)(s)->preload);
typedef struct {
fifo_t fifo;
double step_mult;
int is_fast, x_fade_len, preload;
} stage_t;
typedef struct {
int num_stages0, num_stages, flushing;
int fade_len, slew_len, xfade, stage_inc, switch_stage_num;
double new_io_ratio, default_io_ratio;
stage_t * stages;
fifo_t output_fifo;
half_iir_t halfer;
stream_t current, fadeout; /* Current/fade-in, fadeout streams. */
} rate_t;
static float fade_coefs[(2 << FADE_LEN_BITS) + 1];
static void vr_init(rate_t * p, double default_io_ratio, int num_stages, double mult)
{
int i;
assert(num_stages >= 0);
memset(p, 0, sizeof(*p));
p->num_stages0 = num_stages;
p->num_stages = num_stages = max(num_stages, 1);
p->stages = (stage_t *)calloc((unsigned)num_stages + 1, sizeof(*p->stages)) + 1;
for (i = -1; i < p->num_stages; ++i) {
stage_t * s = &p->stages[i];
fifo_create(&s->fifo, sizeof(float));
s->step_mult = 2 * MULT32 / shiftl(2, i);
s->preload = i < 0? 0 : i == 0? 2 * HALF_FIR_LEN_2 : 3 * HALF_FIR_LEN_2 / 2;
stage_preload(s);
s->is_fast = true;
lsx_debug("%-3i preload=%i", i, s->preload);
}
fifo_create(&p->output_fifo, sizeof(float));
p->default_io_ratio = default_io_ratio;
if (!fade_coefs[0]) {
for (i = 0; i < iAL(fade_coefs); ++i)
fade_coefs[i] = (float)(.5 * (1 + cos(M_PI * i / (AL(fade_coefs) - 1))));
prepare_coefs(poly_fir_coefs_u, POLY_FIR_LEN_U, PHASES0_U, PHASES_U, coefs0_u, mult);
prepare_coefs(poly_fir_coefs_d, POLY_FIR_LEN_D, PHASES0_D, PHASES_D, coefs0_d, mult *.5);
}
assert(fade_coefs[0]);
}
static void enter_new_stage(rate_t * p, int occupancy0)
{
p->current.len = shiftr(occupancy0, p->current.stage_num);
p->current.input = stage_read_p(&p->stages[p->current.stage_num]);
p->current.step_mult = p->stages[p->current.stage_num].step_mult;
p->current.is_d = p->current.stage_num >= 0;
if (p->current.is_d)
p->current.step_mult *= .5;
}
static void set_step(stream_t * p, double io_ratio)
{
p->step.all = (int64_t)(io_ratio * p->step_mult + .5);
}
static bool set_step_step(stream_t * p, double io_ratio, int slew_len)
{
int64_t dif;
int difi;
stream_t tmp = *p;
set_step(&tmp, io_ratio);
dif = tmp.step.all - p->step.all;
dif = dif < 0? dif - (slew_len >> 1) : dif + (slew_len >> 1);
difi = (int)dif; /* Try to avoid int64_t div. */
p->step_step.all = difi == dif? difi / slew_len : dif / slew_len;
return p->step_step.all != 0;
}
static void vr_set_io_ratio(rate_t * p, double io_ratio, size_t slew_len)
{
assert(io_ratio > 0);
if (slew_len) {
if (!set_step_step(&p->current, io_ratio, p->slew_len = (int)slew_len))
p->slew_len = 0, p->new_io_ratio = 0, p->fadeout.step_step.all = 0;
else {
p->new_io_ratio = io_ratio;
if (p->fade_len)
set_step_step(&p->fadeout, io_ratio, p->slew_len);
}
}
else {
if (p->default_io_ratio) { /* Then this is the first call to this fn. */
int octave = (int)floor(log(io_ratio) / M_LN2);
p->current.stage_num = octave < 0? -1 : min(octave, p->num_stages0-1);
enter_new_stage(p, 0);
}
else if (p->fade_len)
set_step(&p->fadeout, io_ratio);
set_step(&p->current, io_ratio);
if (p->default_io_ratio) FRAC(p->current.at) = FRAC(p->current.step) >> 1;
p->default_io_ratio = 0;
}
}
static bool do_input_stage(rate_t * p, int stage_num, int sign, int min_stage_num)
{
int i = 0;
float * dest;
stage_t * s = &p->stages[stage_num];
stage_t * s1 = &p->stages[stage_num - sign];
float const * src = (float *)fifo_read_ptr(&s1->fifo) + HALF_FIR_LEN_2;
int len = shiftr(fifo_occupancy(&s1->fifo) - HALF_FIR_LEN_2 * 2, sign);
int already_done = fifo_occupancy(&s->fifo) - s->preload;
if ((len -= already_done) <= 0)
return false;
src += shiftl(already_done, sign);
dest = fifo_reserve(&s->fifo, len);
if (stage_num < 0) for (; i < len; ++src)
dest[i++] = double_fir0(src), dest[i++] = double_fir1(src);
else {
bool should_be_fast = p->stage_inc;
if (!s->x_fade_len && stage_num == p->switch_stage_num) {
p->switch_stage_num = 0;
if (s->is_fast != should_be_fast) {
s->x_fade_len = 1 << FADE_LEN_BITS, s->is_fast = should_be_fast, ++p->xfade;
lsx_debug("xfade level %i, inc?=%i", stage_num, p->stage_inc);
}
}
if (s->x_fade_len) {
float const * vol1 = fade_coefs + (s->x_fade_len << 1);
float const * vol2 = fade_coefs + (((1 << FADE_LEN_BITS) - s->x_fade_len) << 1);
int n = min(len, s->x_fade_len);
/*lsx_debug("xfade level %i, inc?=%i len=%i n=%i", stage_num, p->stage_inc, s->x_fade_len, n);*/
if (should_be_fast)
for (; i < n; vol2 += 2, vol1 -= 2, src += 2)
dest[i++] = *vol1 * fast_half_fir(src) + *vol2 * half_fir(src);
else for (; i < n; vol2 += 2, vol1 -= 2, src += 2)
dest[i++] = *vol2 * fast_half_fir(src) + *vol1 * half_fir(src);
s->x_fade_len -= n;
p->xfade -= !s->x_fade_len;
}
if (stage_num < min_stage_num)
for (; i < len; dest[i++] = fast_half_fir(src), src += 2);
else for (; i < len; dest[i++] = half_fir(src), src += 2);
}
if (p->flushing > 0)
stage_preload(s);
return true;
}
static int vr_process(rate_t * p, int olen0)
{
assert(p->num_stages > 0);
if (p->default_io_ratio)
vr_set_io_ratio(p, p->default_io_ratio, 0);
{
float * output = fifo_reserve(&p->output_fifo, olen0);
int j, odone0 = 0, min_stage_num = p->current.stage_num;
int occupancy0, max_stage_num = min_stage_num;
if (p->fade_len) {
min_stage_num = min(min_stage_num, p->fadeout.stage_num);
max_stage_num = max(max_stage_num, p->fadeout.stage_num);
}
for (j = min(min_stage_num, 0); j <= max_stage_num; ++j)
if (j && !do_input_stage(p, j, j < 0? -1 : 1, min_stage_num))
break;
if (p->flushing > 0)
p->flushing = -1;
occupancy0 = shiftl(max(0,stage_occupancy(&p->stages[max_stage_num])), max_stage_num);
p->current.len = shiftr(occupancy0, p->current.stage_num);
p->current.input = stage_read_p(&p->stages[p->current.stage_num]);
if (p->fade_len) {
p->fadeout.len = shiftr(occupancy0, p->fadeout.stage_num);
p->fadeout.input = stage_read_p(&p->stages[p->fadeout.stage_num]);
}
while (odone0 < olen0) {
int odone, odone2, olen = olen0 - odone0, stage_dif = 0, shift;
float buf[64 << 1];
olen = min(olen, (int)(AL(buf) >> 1));
if (p->slew_len)
olen = min(olen, p->slew_len);
else if (p->new_io_ratio) {
set_step(&p->current, p->new_io_ratio);
set_step(&p->fadeout, p->new_io_ratio);
p->fadeout.step_step.all = p->current.step_step.all = 0;
p->new_io_ratio = 0;
}
if (!p->flushing && !p->fade_len && !p->xfade) {
if (p->current.is_d) {
if (INT(p->current.step) && FRAC(p->current.step))
stage_dif = 1, ++max_stage_num;
else if (!INT(p->current.step) && FRAC(p->current.step) < (1u << 31))
stage_dif = -1, --min_stage_num;
} else if (INT(p->current.step) > 1 && FRAC(p->current.step))
stage_dif = 1, ++max_stage_num;
}
if (stage_dif) {
int n = p->current.stage_num + stage_dif;
if (n >= p->num_stages)
--max_stage_num;
else {
p->stage_inc = stage_dif > 0;
p->fadeout = p->current;
p->current.stage_num += stage_dif;
if (!p->stage_inc)
p->switch_stage_num = p->current.stage_num;
if ((p->current.stage_num < 0 && stage_dif < 0) ||
(p->current.stage_num > 0 && stage_dif > 0)) {
stage_t * s = &p->stages[p->current.stage_num];
fifo_clear(&s->fifo);
stage_preload(s);
s->is_fast = false;
do_input_stage(p, p->current.stage_num, stage_dif, p->current.stage_num);
}
if (p->current.stage_num > 0 && stage_dif < 0) {
int idone = INT(p->current.at);
stage_t * s = &p->stages[p->current.stage_num];
fifo_trim_to(&s->fifo, 2 * HALF_FIR_LEN_2 + idone + (POLY_FIR_LEN_D >> 1));
do_input_stage(p, p->current.stage_num, 1, p->current.stage_num);
}
enter_new_stage(p, occupancy0);
shift = -stage_dif;
#define lshift(x,by) (x)=(by)>0?(x)<<(by):(x)>>-(by)
lshift(p->current.at.all, shift);
shift += p->fadeout.is_d - p->current.is_d;
lshift(p->current.step.all, shift);
lshift(p->current.step_step.all, shift);
p->fade_len = AL(fade_coefs) - 1;
lsx_debug("switch from stage %i to %i, x2 from %i to %i", p->fadeout.stage_num, p->current.stage_num, p->fadeout.is_d, p->current.is_d);
}
}
if (p->fade_len) {
float const * vol1 = fade_coefs + p->fade_len;
float const * vol2 = fade_coefs + (iAL(fade_coefs) - 1 - p->fade_len);
int olen2 = (olen = min(olen, p->fade_len >> 1)) << 1;
/* x2 is more fine-grained so may fail to produce a pair of samples
* where x1 would not (the x1 second sample is a zero so is always
* available). So do x2 first, then feed odone to the second one. */
memset(buf, 0, sizeof(*buf) * (size_t)olen2);
if (p->current.is_d && p->fadeout.is_d) {
odone = poly_fir_fade_d(&p->current, vol1,-1, buf, olen2);
odone2 = poly_fir_fade_d(&p->fadeout, vol2, 1, buf, odone);
} else if (p->current.is_d) {
odone = poly_fir_fade_d(&p->current, vol1,-1, buf, olen2);
odone2 = poly_fir_fade_u(&p->fadeout, vol2, 2, buf, odone);
} else {
assert(p->fadeout.is_d);
odone = poly_fir_fade_d(&p->fadeout, vol2, 1, buf, olen2);
odone2 = poly_fir_fade_u(&p->current, vol1,-2, buf, odone);
}
assert(odone == odone2);
(void)odone2;
p->fade_len -= odone;
if (!p->fade_len) {
if (p->stage_inc)
p->switch_stage_num = min_stage_num++;
else
--max_stage_num;
}
half_iir(&p->halfer, &output[odone0], buf, odone >>= 1);
}
else if (p->current.is_d) {
odone = poly_fir_d(&p->current, buf, olen << 1) >> 1;
half_iir(&p->halfer, &output[odone0], buf, odone);
}
else {
odone = poly_fir_u(&p->current, &output[odone0], olen);
if (p->num_stages0)
half_phase(&p->halfer, &output[odone0], odone);
}
odone0 += odone;
if (p->slew_len)
p->slew_len -= odone;
if (odone != olen)
break; /* Need more input. */
} {
int from = max(0, max_stage_num), to = min(0, min_stage_num);
int i, idone = shiftr(INT(p->current.at), from - p->current.stage_num);
INT(p->current.at) -= shiftl(idone, from - p->current.stage_num);
if (p->fade_len)
INT(p->fadeout.at) -= shiftl(idone, from - p->fadeout.stage_num);
for (i = from; i >= to; --i, idone <<= 1)
fifo_read(&p->stages[i].fifo, idone, NULL);
}
fifo_trim_by(&p->output_fifo, olen0 - odone0);
return odone0;
}
}
static float * vr_input(rate_t * p, float const * input, size_t n)
{
return fifo_write(&p->stages[0].fifo, (int)n, input);
}
static float const * vr_output(rate_t * p, float * output, size_t * n)
{
fifo_t * fifo = &p->output_fifo;
if (1 || !p->num_stages0)
return fifo_read(fifo, (int)(*n = min(*n, (size_t)fifo_occupancy(fifo))), output);
else { /* Ignore this complication for now. */
int const IIR_DELAY = 2;
float * ptr = fifo_read_ptr(fifo);
int olen = min((int)*n, max(0, fifo_occupancy(fifo) - IIR_DELAY));
*n = (size_t)olen;
if (output)
memcpy(output, ptr + IIR_DELAY, *n * sizeof(*output));
fifo_read(fifo, olen, NULL);
return ptr + IIR_DELAY;
}
}
static void vr_flush(rate_t * p)
{
if (!p->flushing) {
stage_preload(&p->stages[0]);
++p->flushing;
}
}
static void vr_close(rate_t * p)
{
int i;
fifo_delete(&p->output_fifo);
for (i = -1; i < p->num_stages; ++i) {
stage_t * s = &p->stages[i];
fifo_delete(&s->fifo);
}
free(p->stages - 1);
}
static double vr_delay(rate_t * p)
{
return 100; /* TODO */
(void)p;
}
static void vr_sizes(size_t * shared, size_t * channel)
{
*shared = 0;
*channel = sizeof(rate_t);
}
static char const * vr_create(void * channel, void * shared,double max_io_ratio,
void * q_spec, void * r_spec, double scale)
{
double x = max_io_ratio;
int n;
for (n = 0; x > 1; x *= .5, ++n);
vr_init(channel, max_io_ratio, n, scale);
return 0;
(void)shared, (void)q_spec, (void)r_spec;
}
static char const * vr_id(void)
{
return "single-precision variable-rate";
}
typedef void (* fn_t)(void);
fn_t _soxr_vr32_cb[] = {
(fn_t)vr_input,
(fn_t)vr_process,
(fn_t)vr_output,
(fn_t)vr_flush,
(fn_t)vr_close,
(fn_t)vr_delay,
(fn_t)vr_sizes,
(fn_t)vr_create,
(fn_t)vr_set_io_ratio,
(fn_t)vr_id,
};