RetroArch/audio/resamplers/resampler.h

/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2014 - Daniel De Matteis
 * 
 *  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 __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <stdint.h>
#include <math.h>
#include "../../boolean.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846264338327
#endif

#define RESAMPLER_SIMD_SSE      (1 << 0)
#define RESAMPLER_SIMD_SSE2     (1 << 1)
#define RESAMPLER_SIMD_VMX      (1 << 2)
#define RESAMPLER_SIMD_VMX128   (1 << 3)
#define RESAMPLER_SIMD_AVX      (1 << 4)
#define RESAMPLER_SIMD_NEON     (1 << 5)
#define RESAMPLER_SIMD_SSE3     (1 << 6)
#define RESAMPLER_SIMD_SSSE3    (1 << 7)
#define RESAMPLER_SIMD_MMX      (1 << 8)
#define RESAMPLER_SIMD_MMXEXT   (1 << 9)
#define RESAMPLER_SIMD_SSE4     (1 << 10)
#define RESAMPLER_SIMD_SSE42    (1 << 11)
#define RESAMPLER_SIMD_AVX2     (1 << 12)
#define RESAMPLER_SIMD_VFPU     (1 << 13)
#define RESAMPLER_SIMD_PS       (1 << 14)

/* A bit-mask of all supported SIMD instruction sets.
 * Allows an implementation to pick different 
 * dspfilter_implementation structs.
 */
typedef unsigned resampler_simd_mask_t;

#define RESAMPLER_API_VERSION 1

struct resampler_data
{
   const float *data_in;
   float *data_out;

   size_t input_frames;
   size_t output_frames;

   double ratio;
};

/* Bandwidth factor. Will be < 1.0 for downsampling, > 1.0 for upsampling. 
 * Corresponds to expected resampling ratio. */
typedef void *(*resampler_init_t)(double bandwidth_mod,
      resampler_simd_mask_t mask);

/* Frees the handle. */
typedef void (*resampler_free_t)(void *data);

/* Processes input data. */
typedef void (*resampler_process_t)(void *_data, struct resampler_data *data);

typedef struct rarch_resampler
{
   resampler_init_t     init;
   resampler_process_t  process;
   resampler_free_t     free;

   /* Must be RESAMPLER_API_VERSION */
   unsigned api_version;

   /* Human readable identifier of implementation. */
   const char *ident;

   /* Computer-friendly short version of ident.
    * Lower case, no spaces and special characters, etc. */
   const char *short_ident; 
} rarch_resampler_t;

typedef struct audio_frame_float
{
   float l;
   float r;
} audio_frame_float_t;

extern rarch_resampler_t sinc_resampler;
extern rarch_resampler_t CC_resampler;
extern rarch_resampler_t nearest_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)

#ifdef __cplusplus
}
#endif

#endif