src/audio/SDL_audio_c.h
author Ryan C. Gordon
Fri, 06 Jan 2017 01:02:58 -0500
changeset 10764 f9bf759e9dd1
parent 10758 e0fd49c1a5b7
child 10790 92726dd20acd
permissions -rw-r--r--
audio: Fixed SDL_AudioStreamGet() function parameters.

There was a draft of this where it did audio conversion into the final buffer,
if there was enough room available past what you asked for, but that interface
got removed, so the parameters didn't make sense (and we were using the
wrong one in any case, too!).
     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 /* Functions to get a list of "close" audio formats */
    40 extern SDL_AudioFormat SDL_FirstAudioFormat(SDL_AudioFormat format);
    41 extern SDL_AudioFormat SDL_NextAudioFormat(void);
    42 
    43 /* Function to calculate the size and silence for a SDL_AudioSpec */
    44 extern void SDL_CalculateAudioSpec(SDL_AudioSpec * spec);
    45 
    46 void SDLCALL SDL_Convert_S8_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    47 void SDLCALL SDL_Convert_U8_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    48 void SDLCALL SDL_Convert_S16_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    49 void SDLCALL SDL_Convert_U16_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    50 void SDLCALL SDL_Convert_S32_to_F32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    51 void SDLCALL SDL_Convert_F32_to_S8(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    52 void SDLCALL SDL_Convert_F32_to_U8(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    53 void SDLCALL SDL_Convert_F32_to_S16(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    54 void SDLCALL SDL_Convert_F32_to_U16(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    55 void SDLCALL SDL_Convert_F32_to_S32(SDL_AudioCVT *cvt, SDL_AudioFormat format);
    56 void SDL_Upsample_Arbitrary(SDL_AudioCVT *cvt, const int channels);
    57 void SDL_Upsample_Multiple(SDL_AudioCVT *cvt, const int channels);
    58 void SDL_Downsample_Arbitrary(SDL_AudioCVT *cvt, const int channels);
    59 void SDL_Downsample_Multiple(SDL_AudioCVT *cvt, const int channels);
    60 
    61 
    62 /* SDL_AudioStream is a new audio conversion interface. It
    63     might eventually become a public API.
    64    The benefits vs SDL_AudioCVT:
    65     - it can handle resampling data in chunks without generating
    66       artifacts, when it doesn't have the complete buffer available.
    67     - it can handle incoming data in any variable size.
    68     - You push data as you have it, and pull it when you need it
    69 
    70     (Note that currently this converts as data is put into the stream, so
    71     you need to push more than a handful of bytes if you want decent
    72     resampling. This can be changed later.)
    73  */
    74 
    75 /* this is opaque to the outside world. */
    76 typedef struct SDL_AudioStream SDL_AudioStream;
    77 
    78 /* create a new stream */
    79 SDL_AudioStream *SDL_NewAudioStream(const SDL_AudioFormat src_format,
    80                                     const Uint8 src_channels,
    81                                     const int src_rate,
    82                                     const SDL_AudioFormat dst_format,
    83                                     const Uint8 dst_channels,
    84                                     const int dst_rate);
    85 
    86 /* add data to be converted/resampled to the stream */
    87 int SDL_AudioStreamPut(SDL_AudioStream *stream, const void *buf, const Uint32 len);
    88 
    89 /* get converted/resampled data from the stream */
    90 int SDL_AudioStreamGet(SDL_AudioStream *stream, void *buf, const Uint32 len);
    91 
    92 /* clear any pending data in the stream without converting it. */
    93 void SDL_AudioStreamClear(SDL_AudioStream *stream);
    94 
    95 /* number of converted/resampled bytes available */
    96 int SDL_AudioStreamAvailable(SDL_AudioStream *stream);
    97 
    98 /* dispose of a stream */
    99 void SDL_FreeAudioStream(SDL_AudioStream *stream);
   100 
   101 #endif
   102 
   103 /* vi: set ts=4 sw=4 expandtab: */