mirror of
https://github.com/libretro/RetroArch.git
synced 2024-11-28 18:50:29 +00:00
278 lines
7.4 KiB
C
278 lines
7.4 KiB
C
/* SSNES - A frontend for libretro.
|
|
* Copyright (C) 2010-2012 - Hans-Kristian Arntzen
|
|
*
|
|
* SSNES is free software: you can redistribute it and/or modify it under the terms
|
|
* of the GNU General Public License as published by the Free Software Found-
|
|
* ation, either version 3 of the License, or (at your option) any later version.
|
|
*
|
|
* SSNES 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with SSNES.
|
|
* If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
// Bog-standard windowed SINC implementation.
|
|
// Only suitable as an upsampler, as there is no low-pass filter stage.
|
|
|
|
#include "resampler.h"
|
|
#include <math.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#ifndef RESAMPLER_TEST
|
|
#include "../general.h"
|
|
#else
|
|
#define SSNES_LOG(...)
|
|
#endif
|
|
|
|
#if __SSE__
|
|
#include <xmmintrin.h>
|
|
#endif
|
|
|
|
#define PHASE_BITS 8
|
|
#define SUBPHASE_BITS 16
|
|
|
|
#define PHASES (1 << PHASE_BITS)
|
|
#define PHASES_SHIFT (SUBPHASE_BITS)
|
|
#define SUBPHASES (1 << SUBPHASE_BITS)
|
|
#define SUBPHASES_SHIFT 0
|
|
#define SUBPHASES_MASK ((1 << SUBPHASE_BITS) - 1)
|
|
#define PHASES_WRAP (1 << (PHASE_BITS + SUBPHASE_BITS))
|
|
#define FRAMES_SHIFT (PHASE_BITS + SUBPHASE_BITS)
|
|
|
|
#define SIDELOBES 16
|
|
#define TAPS (SIDELOBES * 2)
|
|
#define CUTOFF 0.9
|
|
|
|
#define PHASE_INDEX 0
|
|
#define DELTA_INDEX 1
|
|
|
|
struct ssnes_resampler
|
|
{
|
|
float phase_table[PHASES][2][TAPS];
|
|
float buffer_l[2 * TAPS];
|
|
float buffer_r[2 * TAPS];
|
|
|
|
unsigned ptr;
|
|
|
|
uint32_t time;
|
|
};
|
|
|
|
void resampler_preinit(ssnes_resampler_t *re, double omega, double *samples_offset)
|
|
{
|
|
*samples_offset = SIDELOBES + 1;
|
|
for (int i = 0; i < 2 * SIDELOBES; i++)
|
|
{
|
|
re->buffer_l[i] = re->buffer_l[i + TAPS] = cos((i - (SIDELOBES - 1)) * omega);
|
|
re->buffer_r[i] = re->buffer_r[i + TAPS] = re->buffer_l[i];
|
|
}
|
|
|
|
re->time = 0;
|
|
re->ptr = 0;
|
|
}
|
|
|
|
static inline double sinc(double val)
|
|
{
|
|
if (fabs(val) < 0.00001)
|
|
return 1.0;
|
|
else
|
|
return sin(val) / val;
|
|
}
|
|
|
|
static inline double lanzcos(double index)
|
|
{
|
|
return sinc(index);
|
|
}
|
|
|
|
static void init_sinc_table(ssnes_resampler_t *resamp)
|
|
{
|
|
// Sinc phases: [..., p + 3, p + 2, p + 1, p + 0, p - 1, p - 2, p - 3, p - 4, ...]
|
|
for (int i = 0; i < PHASES; i++)
|
|
{
|
|
for (int j = 0; j < TAPS; j++)
|
|
{
|
|
double p = (double)i / PHASES;
|
|
double sinc_phase = M_PI * (p + (SIDELOBES - 1 - j));
|
|
resamp->phase_table[i][PHASE_INDEX][j] = CUTOFF * sinc(CUTOFF * sinc_phase) *
|
|
lanzcos(sinc_phase / SIDELOBES);
|
|
}
|
|
}
|
|
|
|
// Optimize linear interpolation.
|
|
for (int i = 0; i < PHASES - 1; i++)
|
|
{
|
|
for (int j = 0; j < TAPS; j++)
|
|
{
|
|
resamp->phase_table[i][DELTA_INDEX][j] =
|
|
(resamp->phase_table[i + 1][PHASE_INDEX][j] - resamp->phase_table[i][PHASE_INDEX][j]) / SUBPHASES;
|
|
}
|
|
}
|
|
|
|
// Interpolation between [PHASES - 1] => [PHASES]
|
|
for (int j = 0; j < TAPS; j++)
|
|
{
|
|
double p = 1.0;
|
|
double sinc_phase = M_PI * (p + (SIDELOBES - 1 - j));
|
|
double phase = CUTOFF * sinc(CUTOFF * sinc_phase) * lanzcos(sinc_phase / SIDELOBES);
|
|
|
|
float result = (phase - resamp->phase_table[PHASES - 1][PHASE_INDEX][j]) / SUBPHASES;
|
|
resamp->phase_table[PHASES - 1][DELTA_INDEX][j] = result;
|
|
}
|
|
}
|
|
|
|
// No memalign() for us on Win32 ...
|
|
static void *aligned_alloc(size_t boundary, size_t size)
|
|
{
|
|
void *ptr = malloc(boundary + size + sizeof(uintptr_t));
|
|
if (!ptr)
|
|
return NULL;
|
|
|
|
uintptr_t addr = ((uintptr_t)ptr + sizeof(uintptr_t) + boundary) & ~(boundary - 1);
|
|
void **place = (void**)addr;
|
|
place[-1] = ptr;
|
|
|
|
return (void*)addr;
|
|
}
|
|
|
|
static void aligned_free(void *ptr)
|
|
{
|
|
void **p = (void**)ptr;
|
|
free(p[-1]);
|
|
}
|
|
|
|
ssnes_resampler_t *resampler_new(void)
|
|
{
|
|
ssnes_resampler_t *re = (ssnes_resampler_t*)aligned_alloc(16, sizeof(*re));
|
|
if (!re)
|
|
return NULL;
|
|
|
|
memset(re, 0, sizeof(*re));
|
|
|
|
init_sinc_table(re);
|
|
|
|
#if __SSE__
|
|
SSNES_LOG("Sinc resampler [SSE]\n");
|
|
#else
|
|
SSNES_LOG("Sinc resampler [C]\n");
|
|
#endif
|
|
|
|
return re;
|
|
}
|
|
|
|
#if __SSE__
|
|
static void process_sinc(ssnes_resampler_t *resamp, float *out_buffer)
|
|
{
|
|
__m128 sum_l = _mm_setzero_ps();
|
|
__m128 sum_r = _mm_setzero_ps();
|
|
|
|
const float *buffer_l = resamp->buffer_l + resamp->ptr;
|
|
const float *buffer_r = resamp->buffer_r + resamp->ptr;
|
|
|
|
unsigned phase = resamp->time >> PHASES_SHIFT;
|
|
unsigned delta = (resamp->time >> SUBPHASES_SHIFT) & SUBPHASES_MASK;
|
|
__m128 delta_f = _mm_set1_ps(delta);
|
|
|
|
const float *phase_table = resamp->phase_table[phase][PHASE_INDEX];
|
|
const float *delta_table = resamp->phase_table[phase][DELTA_INDEX];
|
|
|
|
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);
|
|
|
|
__m128 phases = _mm_load_ps(phase_table + i);
|
|
__m128 deltas = _mm_load_ps(delta_table + i);
|
|
|
|
__m128 sinc = _mm_add_ps(phases, _mm_mul_ps(deltas, delta_f));
|
|
|
|
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));
|
|
}
|
|
|
|
// Them annoying shuffles :V
|
|
// sum_l = { l3, l2, l1, l0 }
|
|
// sum_r = { r3, r2, r1, r0 }
|
|
|
|
__m128 sum = _mm_add_ps(_mm_shuffle_ps(sum_l, sum_r, _MM_SHUFFLE(1, 0, 1, 0)),
|
|
_mm_shuffle_ps(sum_l, sum_r, _MM_SHUFFLE(3, 2, 3, 2)));
|
|
|
|
// sum = { r1, r0, l1, l0 } + { r3, r2, l3, l2 }
|
|
// sum = { R1, R0, L1, L0 }
|
|
|
|
sum = _mm_add_ps(_mm_shuffle_ps(sum, sum, _MM_SHUFFLE(3, 3, 1, 1)), sum);
|
|
|
|
// sum = {R1, R1, L1, L1 } + { R1, R0, L1, L0 }
|
|
// sum = { X, R, X, L }
|
|
|
|
// Store L
|
|
_mm_store_ss(out_buffer + 0, sum);
|
|
|
|
// movehl { X, R, X, L } == { X, R, X, R }
|
|
_mm_store_ss(out_buffer + 1, _mm_movehl_ps(sum, sum));
|
|
}
|
|
#else // Plain ol' C99
|
|
static void process_sinc(ssnes_resampler_t *resamp, float *out_buffer)
|
|
{
|
|
float sum_l = 0.0f;
|
|
float sum_r = 0.0f;
|
|
const float *buffer_l = resamp->buffer_l + resamp->ptr;
|
|
const float *buffer_r = resamp->buffer_r + resamp->ptr;
|
|
|
|
unsigned phase = resamp->time >> PHASES_SHIFT;
|
|
unsigned delta = (resamp->time >> SUBPHASES_SHIFT) & SUBPHASES_MASK;
|
|
float delta_f = (float)delta;
|
|
|
|
const float *phase_table = resamp->phase_table[phase][PHASE_INDEX];
|
|
const float *delta_table = resamp->phase_table[phase][DELTA_INDEX];
|
|
|
|
for (unsigned i = 0; i < TAPS; i++)
|
|
{
|
|
float sinc_val = phase_table[i] + delta_f * delta_table[i];
|
|
sum_l += buffer_l[i] * sinc_val;
|
|
sum_r += buffer_r[i] * sinc_val;
|
|
}
|
|
|
|
out_buffer[0] = sum_l;
|
|
out_buffer[1] = sum_r;
|
|
}
|
|
#endif
|
|
|
|
void resampler_process(ssnes_resampler_t *re, struct resampler_data *data)
|
|
{
|
|
uint32_t ratio = PHASES_WRAP / data->ratio;
|
|
|
|
const float *input = data->data_in;
|
|
float *output = data->data_out;
|
|
size_t frames = data->input_frames;
|
|
size_t out_frames = 0;
|
|
|
|
while (frames)
|
|
{
|
|
process_sinc(re, output);
|
|
output += 2;
|
|
out_frames++;
|
|
|
|
re->time += ratio;
|
|
while (re->time >= PHASES_WRAP)
|
|
{
|
|
re->buffer_l[re->ptr + TAPS] = re->buffer_l[re->ptr] = *input++;
|
|
re->buffer_r[re->ptr + TAPS] = re->buffer_r[re->ptr] = *input++;
|
|
re->ptr = (re->ptr + 1) & (TAPS - 1);
|
|
|
|
re->time -= PHASES_WRAP;
|
|
frames--;
|
|
}
|
|
}
|
|
|
|
data->output_frames = out_frames;
|
|
}
|
|
|
|
void resampler_free(ssnes_resampler_t *re)
|
|
{
|
|
aligned_free(re);
|
|
}
|
|
|