src/audio/SDL_audio_c.h
author Ryan C. Gordon
Mon, 09 Jan 2017 06:00:58 -0500
changeset 10799 234f71894a52
parent 10791 64c46e09df9d
child 10815 71bbe3233508
permissions -rw-r--r--
audio: Replaced older resamplers in SDL_AudioCVT with the new ones.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 #ifndef SDL_audio_c_h_
    23 #define SDL_audio_c_h_
    24 
    25 #include "../SDL_internal.h"
    26 
    27 #ifndef DEBUG_CONVERT
    28 #define DEBUG_CONVERT 0
    29 #endif
    30 
    31 #if DEBUG_CONVERT
    32 #define LOG_DEBUG_CONVERT(from, to) fprintf(stderr, "Converting %s to %s.\n", from, to);
    33 #else
    34 #define LOG_DEBUG_CONVERT(from, to)
    35 #endif
    36 
    37 /* Functions and variables exported from SDL_audio.c for SDL_sysaudio.c */
    38 
    39 #ifdef HAVE_LIBSAMPLERATE_H
    40 #include "samplerate.h"
    41 extern SDL_bool SRC_available;
    42 extern SRC_STATE* (*SRC_src_new)(int converter_type, int channels, int *error);
    43 extern int (*SRC_src_process)(SRC_STATE *state, SRC_DATA *data);
    44 extern int (*SRC_src_reset)(SRC_STATE *state);
    45 extern SRC_STATE* (*SRC_src_delete)(SRC_STATE *state);
    46 extern const char* (*SRC_src_strerror)(int error);
    47 #endif
    48 
    49 /* Functions to get a list of "close" audio formats */
    50 extern SDL_AudioFormat SDL_FirstAudioFormat(SDL_AudioFormat format);
    51 extern SDL_AudioFormat SDL_NextAudioFormat(void);
    52 
    53 /* Function to calculate the size and silence for a SDL_AudioSpec */
    54 extern void SDL_CalculateAudioSpec(SDL_AudioSpec * spec);
    55 
    56 void SDLCALL SDL_Convert_S8_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    57 void SDLCALL SDL_Convert_U8_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    58 void SDLCALL SDL_Convert_S16_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    59 void SDLCALL SDL_Convert_U16_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    60 void SDLCALL SDL_Convert_S32_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    61 void SDLCALL SDL_Convert_F32_to_S8(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    62 void SDLCALL SDL_Convert_F32_to_U8(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    63 void SDLCALL SDL_Convert_F32_to_S16(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    64 void SDLCALL SDL_Convert_F32_to_U16(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    65 void SDLCALL SDL_Convert_F32_to_S32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    66 
    67 
    68 /* SDL_AudioStream is a new audio conversion interface. It
    69     might eventually become a public API.
    70    The benefits vs SDL_AudioCVT:
    71     - it can handle resampling data in chunks without generating
    72       artifacts, when it doesn't have the complete buffer available.
    73     - it can handle incoming data in any variable size.
    74     - You push data as you have it, and pull it when you need it
    75 
    76     (Note that currently this converts as data is put into the stream, so
    77     you need to push more than a handful of bytes if you want decent
    78     resampling. This can be changed later.)
    79  */
    80 
    81 /* this is opaque to the outside world. */
    82 typedef struct SDL_AudioStream SDL_AudioStream;
    83 
    84 /* create a new stream */
    85 SDL_AudioStream *SDL_NewAudioStream(const SDL_AudioFormat src_format,
    86                                     const Uint8 src_channels,
    87                                     const int src_rate,
    88                                     const SDL_AudioFormat dst_format,
    89                                     const Uint8 dst_channels,
    90                                     const int dst_rate);
    91 
    92 /* add data to be converted/resampled to the stream */
    93 int SDL_AudioStreamPut(SDL_AudioStream *stream, const void *buf, const Uint32 len);
    94 
    95 /* get converted/resampled data from the stream */
    96 int SDL_AudioStreamGet(SDL_AudioStream *stream, void *buf, const Uint32 len);
    97 
    98 /* clear any pending data in the stream without converting it. */
    99 void SDL_AudioStreamClear(SDL_AudioStream *stream);
   100 
   101 /* number of converted/resampled bytes available */
   102 int SDL_AudioStreamAvailable(SDL_AudioStream *stream);
   103 
   104 /* dispose of a stream */
   105 void SDL_FreeAudioStream(SDL_AudioStream *stream);
   106 
   107 #endif
   108 
   109 /* vi: set ts=4 sw=4 expandtab: */