RetroArch/audio/resampler.h
2013-02-13 21:55:58 +01:00

77 lines
2.2 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - Hans-Kristian Arntzen
*
* RetroArch 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.
*
* RetroArch 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 RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __RARCH_RESAMPLER_H
#define __RARCH_RESAMPLER_H
#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif
#include <stddef.h>
#include <stdint.h>
#include <math.h>
#include "../boolean.h"
// M_PI is left out of ISO C99 :(
#ifndef M_PI
#define M_PI 3.14159265358979323846264338327
#endif
typedef float sample_t;
struct resampler_data
{
const sample_t *data_in;
sample_t *data_out;
size_t input_frames;
size_t output_frames;
double ratio;
};
typedef struct rarch_resampler
{
void *(*init)(double bandwidth_mod); // Bandwidth factor. Will be < 1.0 for downsampling, > 1.0 for upsamling. Corresponds to expected resampling ratio.
void (*process)(void *re, struct resampler_data *data);
void (*free)(void *re);
const char *ident;
} rarch_resampler_t;
extern const rarch_resampler_t hermite_resampler;
extern const rarch_resampler_t sinc_resampler;
// Reallocs resampler. Will free previous handle before allocating a new one.
// If ident is NULL, first resampler will be used.
bool rarch_resampler_realloc(void **re, const rarch_resampler_t **backend, const char *ident, double bw_ratio);
// Convenience macros.
// freep makes sure to set handles to NULL to avoid double-free in rarch_resampler_realloc.
#define rarch_resampler_freep(backend, handle) do { \
if (*(backend) && *(handle)) \
(*backend)->free(*handle); \
*backend = NULL; \
*handle = NULL; \
} while(0)
#define rarch_resampler_process(backend, handle, data) do { \
(backend)->process(handle, data); \
} while(0)
#endif