+/* Copyright (C) 2010-2020 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (audio_resampler.h).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __LIBRETRO_SDK_AUDIO_RESAMPLER_DRIVER_H
+#define __LIBRETRO_SDK_AUDIO_RESAMPLER_DRIVER_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#include <boolean.h>
+#include <retro_common_api.h>
+
+RETRO_BEGIN_DECLS
+
+#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)
+
+enum resampler_quality
+{
+ RESAMPLER_QUALITY_DONTCARE = 0,
+ RESAMPLER_QUALITY_LOWEST,
+ RESAMPLER_QUALITY_LOWER,
+ RESAMPLER_QUALITY_NORMAL,
+ RESAMPLER_QUALITY_HIGHER,
+ RESAMPLER_QUALITY_HIGHEST
+};
+
+/* 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
+
+/**
+ * A struct that groups the input and output of a resampler.
+ */
+struct resampler_data
+{
+ /**
+ * The buffer containing the data to be resampled.
+ */
+ const float *data_in;
+
+ /**
+ * The buffer that will be used to store resampled output.
+ * Must be allocated in advance, and must not be the same as data_in.
+ */
+ float *data_out;
+
+ /**
+ * The size of ::data_in, in frames (\em not bytes or samples).
+ * For example, 32-bit stereo frames would consist of 8 bytes
+ * (two 4-byte floats per frame).
+ */
+ size_t input_frames;
+
+ /**
+ * The number of frames (\em not bytes or samples) that the resampler produced.
+ * This value is set by the resampler.
+ * The resampler may not provide the same number of frames with each use,
+ * so be sure to check this value.
+ */
+ size_t output_frames;
+
+ /**
+ * The desired ratio of output_frames to input_frames.
+ * This value is used to determine the number of frames written to \c data_out.
+ * If this value is (almost) equal to 1,
+ * then resampling may be skipped.
+ */
+ 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, enum resampler_quality quality,
+ 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 retro_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;
+} retro_resampler_t;
+
+typedef struct audio_frame_float
+{
+ float l;
+ float r;
+} audio_frame_float_t;
+
+extern retro_resampler_t sinc_resampler;
+#ifdef HAVE_CC_RESAMPLER
+extern retro_resampler_t CC_resampler;
+#endif
+extern retro_resampler_t nearest_resampler;
+
+/**
+ * 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);
+
+/**
+ * retro_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 retro_resampler_realloc(void **re, const retro_resampler_t **backend,
+ const char *ident, enum resampler_quality quality, double bw_ratio);
+
+RETRO_END_DECLS
+
+#endif