RetroArch/audio/audio_resampler_driver.h

/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2015 - 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 __AUDIO_RESAMPLER_DRIVER_H
#define __AUDIO_RESAMPLER_DRIVER_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 
 * resampler_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;
};

/* Returns true if config key was found. Otherwise, 
 * returns false, and sets value to default value.
 */
typedef int (*resampler_config_get_float_t)(void *userdata,
      const char *key, float *value, float default_value);

typedef int (*resampler_config_get_int_t)(void *userdata,
      const char *key, int *value, int default_value);

/* Allocates an array with values. free() with resampler_config_free_t. */
typedef int (*resampler_config_get_float_array_t)(void *userdata, 
      const char *key, float **values, unsigned *out_num_values,
      const float *default_values, unsigned num_default_values);

typedef int (*resampler_config_get_int_array_t)(void *userdata,
      const char *key, int **values, unsigned *out_num_values,
      const int *default_values, unsigned num_default_values);

typedef int (*resampler_config_get_string_t)(void *userdata,
      const char *key, char **output, const char *default_output);

/* Calls free() in host runtime. Sometimes needed on Windows. 
 * free() on NULL is fine. */
typedef void (*resampler_config_free_t)(void *ptr);

struct resampler_config
{
   resampler_config_get_float_t get_float;
   resampler_config_get_int_t get_int;

   resampler_config_get_float_array_t get_float_array;
   resampler_config_get_int_array_t get_int_array;

   resampler_config_get_string_t get_string;
   /* Avoid problems where resampler plug and host are 
    * linked against different C runtimes. */
   resampler_config_free_t free; 
};

/* Bandwidth factor. Will be < 1.0 for downsampling, > 1.0 for upsampling. 
 * Corresponds to expected resampling ratio. */
typedef void *(*resampler_init_t)(const struct resampler_config *config,
      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;

#ifndef DONT_HAVE_STRING_LIST
/**
 * config_get_audio_resampler_driver_options:
 *
 * Get an enumerated list of all resampler driver names, separated by '|'.
 *
 * Returns: string listing of all resampler driver names, separated by '|'.
 **/
const char* config_get_audio_resampler_driver_options(void);
#endif

/**
 * audio_resampler_driver_find_handle:
 * @index              : index of driver to get handle to.
 *
 * Returns: handle to audio resampler driver at index. Can be NULL
 * if nothing found.
 **/
const void *audio_resampler_driver_find_handle(int index);

/**
 * audio_resampler_driver_find_ident:
 * @index              : index of driver to get handle to.
 *
 * Returns: Human-readable identifier of audio resampler driver at index.
 * Can be NULL if nothing found.
 **/
const char *audio_resampler_driver_find_ident(int index);

/**
 * rarch_resampler_realloc:
 * @re                         : Resampler handle
 * @backend                    : Resampler backend that is about to be set.
 * @ident                      : Identifier name for resampler we want.
 * @bw_ratio                   : Bandwidth ratio.
 *
 * Reallocates resampler. Will free previous handle before 
 * allocating a new one. If ident is NULL, first resampler will be used.
 *
 * Returns: true (1) if successful, otherwise false (0).
 **/
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