Start using LERP optionally for SINC again.

This commit is contained in:
Themaister 2013-02-13 07:39:31 +01:00
parent 9dcbfbba0f
commit d68fe248f3
2 changed files with 85 additions and 12 deletions

View File

@ -22,11 +22,12 @@
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#ifndef RESAMPLER_TEST
#include "../general.h"
#else
#define RARCH_LOG(...)
#define RARCH_LOG(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifdef __SSE__
@ -45,33 +46,43 @@
#define SINC_WINDOW_LANCZOS
#define CUTOFF 0.98
#define PHASE_BITS 11
#define SINC_COEFF_LERP 0
#define SUBPHASE_BITS 10
#define SIDELOBES 2
#define ENABLE_AVX 0
#elif defined(SINC_LOWER_QUALITY)
#define SINC_WINDOW_LANCZOS
#define CUTOFF 0.98
#define PHASE_BITS 12
#define SUBPHASE_BITS 10
#define SINC_COEFF_LERP 0
#define SIDELOBES 4
#define ENABLE_AVX 0
#elif defined(SINC_HIGHER_QUALITY)
#define SINC_WINDOW_KAISER
#define SINC_WINDOW_KAISER_BETA 10.5
#define CUTOFF 0.90
#define PHASE_BITS 16
#define PHASE_BITS 10
#define SUBPHASE_BITS 14
#define SINC_COEFF_LERP 1
#define SIDELOBES 32
#define ENABLE_AVX 1
#elif defined(SINC_HIGHEST_QUALITY)
#define SINC_WINDOW_KAISER
#define SINC_WINDOW_KAISER_BETA 14.5
#define CUTOFF 0.95
#define PHASE_BITS 16
#define PHASE_BITS 10
#define SUBPHASE_BITS 14
#define SINC_COEFF_LERP 1
#define SIDELOBES 128
#define ENABLE_AVX 1
#else
#define SINC_WINDOW_KAISER
#define SINC_WINDOW_KAISER_BETA 5.5
#define CUTOFF 0.825
#define PHASE_BITS 14
#define PHASE_BITS 8
#define SUBPHASE_BITS 16
#define SINC_COEFF_LERP 1
#define SIDELOBES 8
#define ENABLE_AVX 0
#endif
@ -85,14 +96,19 @@
#include <immintrin.h>
#endif
#define SUBPHASE_BITS 10
#define PHASES (1 << (PHASE_BITS + SUBPHASE_BITS))
#define TAPS (SIDELOBES * 2)
#define SUBPHASE_MASK ((1 << SUBPHASE_BITS) - 1)
#define SUBPHASE_MOD (1.0f / (1 << SUBPHASE_BITS))
typedef struct rarch_sinc_resampler
{
#if SINC_COEFF_LERP
sample_t phase_table[1 << PHASE_BITS][TAPS * 2];
#else
sample_t phase_table[1 << PHASE_BITS][TAPS];
#endif
sample_t buffer_l[2 * TAPS];
sample_t buffer_r[2 * TAPS];
@ -124,6 +140,7 @@ static inline double besseli0(double x)
double factorial_mult = 0.0;
double x_pow = 1.0;
double two_div_pow = 1.0;
double x_sqr = x * x;
// Approximate. This is an infinite sum.
// Luckily, it converges rather fast.
@ -132,7 +149,7 @@ static inline double besseli0(double x)
sum += x_pow * two_div_pow / (factorial * factorial);
factorial_mult += 1.0;
x_pow *= x * x;
x_pow *= x_sqr;
two_div_pow *= 0.25;
factorial *= factorial_mult;
}
@ -149,21 +166,47 @@ static inline double window_function(double index)
#endif
static void init_sinc_table(rarch_sinc_resampler_t *resamp, double cutoff,
float *phase_table, int phases, int taps)
float *phase_table, int phases, int taps, bool calculate_delta)
{
double window_mod = window_function(0.0); // Need to normalize w(0) to 1.0.
int stride = calculate_delta ? 2 : 1;
for (int i = 0; i < phases; i++)
{
for (int j = 0; j < taps; j++)
{
int n = j * phases + i;
double window_phase = (double)n / (((1 << PHASE_BITS) * TAPS) - 1.0); // [0, 1].
window_phase = 2.0 * window_phase - 1.0; // [-1, 1]
double window_phase = (double)n / (phases * taps); // [0, 1).
window_phase = 2.0 * window_phase - 1.0; // [-1, 1)
double sinc_phase = SIDELOBES * window_phase;
float val = cutoff * sinc(M_PI * sinc_phase * cutoff) * window_function(window_phase) / window_mod;
phase_table[i * taps + j] = val;
phase_table[i * stride * taps + j] = val;
}
}
if (calculate_delta)
{
for (int i = 0; i < phases - 1; i++)
{
for (int j = 0; j < taps; j++)
{
float delta = phase_table[(i + 1) * stride * taps + j] - phase_table[i * stride * taps + j];
phase_table[(i * stride + 1) * taps + j] = delta;
}
}
int i = phases - 1;
for (int j = 0; j < taps; j++)
{
int n = j * phases + (i + 1);
double window_phase = (double)n / (phases * taps); // [0, 1).
window_phase = 2.0 * window_phase - 1.0; // [-1, 1)
double sinc_phase = SIDELOBES * window_phase;
float val = cutoff * sinc(M_PI * sinc_phase * cutoff) * window_function(window_phase) / window_mod;
float delta = (val - phase_table[i * stride * taps + j]);
phase_table[(i * stride + 1) * taps + j] = delta;
}
}
}
@ -197,10 +240,18 @@ static inline void process_sinc_C(rarch_sinc_resampler_t *resamp, float *out_buf
unsigned phase = resamp->time >> SUBPHASE_BITS;
const float *phase_table = resamp->phase_table[phase];
#if SINC_COEFF_LERP
const float *delta_table = phase_table + TAPS;
float delta = (float)(resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD;
#endif
for (unsigned i = 0; i < TAPS; i++)
{
#if SINC_COEFF_LERP
float sinc_val = phase_table[i] + delta_table[i] * delta;
#else
float sinc_val = phase_table[i];
#endif
sum_l += buffer_l[i] * sinc_val;
sum_r += buffer_r[i] * sinc_val;
}
@ -221,13 +272,22 @@ static void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
unsigned phase = resamp->time >> SUBPHASE_BITS;
const float *phase_table = resamp->phase_table[phase];
#if SINC_COEFF_LERP
const float *delta_table = phase_table + TAPS;
__m256 delta = _mm256_set1_ps((float)(resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
#endif
for (unsigned i = 0; i < TAPS; i += 8)
{
__m256 buf_l = _mm256_loadu_ps(buffer_l + i);
__m256 buf_r = _mm256_loadu_ps(buffer_r + i);
#if SINC_COEFF_LERP
__m256 deltas = _mm256_load_ps(delta_table + i);
__m256 sinc = _mm256_add_ps(_mm256_load_ps(phase_table + i), _mm256_mul_ps(deltas, delta));
#else
__m256 sinc = _mm256_load_ps(phase_table + i);
#endif
sum_l = _mm256_add_ps(sum_l, _mm256_mul_ps(buf_l, sinc));
sum_r = _mm256_add_ps(sum_r, _mm256_mul_ps(buf_r, sinc));
}
@ -257,13 +317,22 @@ static void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
unsigned phase = resamp->time >> SUBPHASE_BITS;
const float *phase_table = resamp->phase_table[phase];
#if SINC_COEFF_LERP
const float *delta_table = phase_table + TAPS;
__m128 delta = _mm_set1_ps((float)(resamp->time & SUBPHASE_MASK) * SUBPHASE_MOD);
#endif
for (unsigned i = 0; i < TAPS; i += 4)
{
__m128 buf_l = _mm_loadu_ps(buffer_l + i);
__m128 buf_r = _mm_loadu_ps(buffer_r + i);
#if SINC_COEFF_LERP
__m128 deltas = _mm_load_ps(delta_table + i);
__m128 sinc = _mm_add_ps(_mm_load_ps(phase_table + i), _mm_mul_ps(deltas, delta));
#else
__m128 sinc = _mm_load_ps(phase_table + i);
#endif
sum_l = _mm_add_ps(sum_l, _mm_mul_ps(buf_l, sinc));
sum_r = _mm_add_ps(sum_r, _mm_mul_ps(buf_r, sinc));
}
@ -295,6 +364,10 @@ static void process_sinc(rarch_sinc_resampler_t *resamp, float *out_buffer)
#error "NEON asm requires at least 8 taps (for now)."
#endif
#if SINC_COEFF_LERP
#error "NEON asm does not support SINC lerp."
#endif
// Need to make this function pointer as Android doesn't have built-in targets
// for NEON and plain ARMv7a.
static void (*process_sinc_func)(rarch_sinc_resampler_t *resamp, float *out_buffer);
@ -367,7 +440,7 @@ static void *resampler_sinc_new(void)
memset(re, 0, sizeof(*re));
init_sinc_table(re, CUTOFF, &re->phase_table[0][0], 1 << PHASE_BITS, TAPS);
init_sinc_table(re, CUTOFF, &re->phase_table[0][0], 1 << PHASE_BITS, TAPS, SINC_COEFF_LERP);
#if defined(__AVX__) && ENABLE_AVX
RARCH_LOG("Sinc resampler [AVX]\n");

View File

@ -11,7 +11,7 @@ TESTS := test-hermite \
test-sinc-highest \
test-snr-sinc-highest
CFLAGS += -O3 -g -Wall -pedantic -std=gnu99 -DRESAMPLER_TEST
CFLAGS += -O3 -g -Wall -pedantic -march=native -std=gnu99 -DRESAMPLER_TEST
LDFLAGS += -lm
all: $(TESTS)