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comparison include/SDL_audio.h @ 1662:782fd950bd46 SDL-1.3

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Revamp of the video system in progress - adding support for multiple displays, multiple windows, and a full video mode selection API. WARNING: None of the video drivers have been updated for the new API yet! The API is still under design and very fluid. The code is now run through a consistent indent format: indent -i4 -nut -nsc -br -ce The headers are being converted to automatically generate doxygen documentation.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 28 May 2006 13:04:16 +0000
parents 8b9d79e7eacf
children 4da1ee79c9af
comparison
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1661:281d3f4870e5 1662:782fd950bd46
18 18
19 Sam Lantinga 19 Sam Lantinga
20 slouken@libsdl.org 20 slouken@libsdl.org
21 */ 21 */
22 22
23 /* Access to the raw audio mixing buffer for the SDL library */ 23 /**
24 * \file SDL_audio.h
25 *
26 * Access to the raw audio mixing buffer for the SDL library
27 */
24 28
25 #ifndef _SDL_audio_h 29 #ifndef _SDL_audio_h
26 #define _SDL_audio_h 30 #define _SDL_audio_h
27 31
28 #include "SDL_stdinc.h" 32 #include "SDL_stdinc.h"
33 #include "SDL_rwops.h" 37 #include "SDL_rwops.h"
34 38
35 #include "begin_code.h" 39 #include "begin_code.h"
36 /* Set up for C function definitions, even when using C++ */ 40 /* Set up for C function definitions, even when using C++ */
37 #ifdef __cplusplus 41 #ifdef __cplusplus
42 /* *INDENT-OFF* */
38 extern "C" { 43 extern "C" {
44 /* *INDENT-ON* */
39 #endif 45 #endif
40 46
41 /* The calculated values in this structure are calculated by SDL_OpenAudio() */ 47 /* The calculated values in this structure are calculated by SDL_OpenAudio() */
42 typedef struct SDL_AudioSpec { 48 typedef struct SDL_AudioSpec
43 int freq; /* DSP frequency -- samples per second */ 49 {
44 Uint16 format; /* Audio data format */ 50 int freq; /* DSP frequency -- samples per second */
45 Uint8 channels; /* Number of channels: 1 mono, 2 stereo */ 51 Uint16 format; /* Audio data format */
46 Uint8 silence; /* Audio buffer silence value (calculated) */ 52 Uint8 channels; /* Number of channels: 1 mono, 2 stereo */
47 Uint16 samples; /* Audio buffer size in samples (power of 2) */ 53 Uint8 silence; /* Audio buffer silence value (calculated) */
48 Uint16 padding; /* Necessary for some compile environments */ 54 Uint16 samples; /* Audio buffer size in samples (power of 2) */
49 Uint32 size; /* Audio buffer size in bytes (calculated) */ 55 Uint16 padding; /* Necessary for some compile environments */
50 /* This function is called when the audio device needs more data. 56 Uint32 size; /* Audio buffer size in bytes (calculated) */
51 'stream' is a pointer to the audio data buffer 57 /* This function is called when the audio device needs more data.
52 'len' is the length of that buffer in bytes. 58 'stream' is a pointer to the audio data buffer
53 Once the callback returns, the buffer will no longer be valid. 59 'len' is the length of that buffer in bytes.
54 Stereo samples are stored in a LRLRLR ordering. 60 Once the callback returns, the buffer will no longer be valid.
55 */ 61 Stereo samples are stored in a LRLRLR ordering.
56 void (SDLCALL *callback)(void *userdata, Uint8 *stream, int len); 62 */
57 void *userdata; 63 void (SDLCALL * callback) (void *userdata, Uint8 * stream, int len);
64 void *userdata;
58 } SDL_AudioSpec; 65 } SDL_AudioSpec;
59 66
60 /* Audio format flags (defaults to LSB byte order) */ 67 /* Audio format flags (defaults to LSB byte order) */
61 #define AUDIO_U8 0x0008 /* Unsigned 8-bit samples */ 68 #define AUDIO_U8 0x0008 /* Unsigned 8-bit samples */
62 #define AUDIO_S8 0x8008 /* Signed 8-bit samples */ 69 #define AUDIO_S8 0x8008 /* Signed 8-bit samples */
63 #define AUDIO_U16LSB 0x0010 /* Unsigned 16-bit samples */ 70 #define AUDIO_U16LSB 0x0010 /* Unsigned 16-bit samples */
64 #define AUDIO_S16LSB 0x8010 /* Signed 16-bit samples */ 71 #define AUDIO_S16LSB 0x8010 /* Signed 16-bit samples */
65 #define AUDIO_U16MSB 0x1010 /* As above, but big-endian byte order */ 72 #define AUDIO_U16MSB 0x1010 /* As above, but big-endian byte order */
66 #define AUDIO_S16MSB 0x9010 /* As above, but big-endian byte order */ 73 #define AUDIO_S16MSB 0x9010 /* As above, but big-endian byte order */
67 #define AUDIO_U16 AUDIO_U16LSB 74 #define AUDIO_U16 AUDIO_U16LSB
68 #define AUDIO_S16 AUDIO_S16LSB 75 #define AUDIO_S16 AUDIO_S16LSB
69 76
70 /* Native audio byte ordering */ 77 /* Native audio byte ordering */
71 #if SDL_BYTEORDER == SDL_LIL_ENDIAN 78 #if SDL_BYTEORDER == SDL_LIL_ENDIAN
76 #define AUDIO_S16SYS AUDIO_S16MSB 83 #define AUDIO_S16SYS AUDIO_S16MSB
77 #endif 84 #endif
78 85
79 86
80 /* A structure to hold a set of audio conversion filters and buffers */ 87 /* A structure to hold a set of audio conversion filters and buffers */
81 typedef struct SDL_AudioCVT { 88 typedef struct SDL_AudioCVT
82 int needed; /* Set to 1 if conversion possible */ 89 {
83 Uint16 src_format; /* Source audio format */ 90 int needed; /* Set to 1 if conversion possible */
84 Uint16 dst_format; /* Target audio format */ 91 Uint16 src_format; /* Source audio format */
85 double rate_incr; /* Rate conversion increment */ 92 Uint16 dst_format; /* Target audio format */
86 Uint8 *buf; /* Buffer to hold entire audio data */ 93 double rate_incr; /* Rate conversion increment */
87 int len; /* Length of original audio buffer */ 94 Uint8 *buf; /* Buffer to hold entire audio data */
88 int len_cvt; /* Length of converted audio buffer */ 95 int len; /* Length of original audio buffer */
89 int len_mult; /* buffer must be len*len_mult big */ 96 int len_cvt; /* Length of converted audio buffer */
90 double len_ratio; /* Given len, final size is len*len_ratio */ 97 int len_mult; /* buffer must be len*len_mult big */
91 void (SDLCALL *filters[10])(struct SDL_AudioCVT *cvt, Uint16 format); 98 double len_ratio; /* Given len, final size is len*len_ratio */
92 int filter_index; /* Current audio conversion function */ 99 void (SDLCALL * filters[10]) (struct SDL_AudioCVT * cvt, Uint16 format);
100 int filter_index; /* Current audio conversion function */
93 } SDL_AudioCVT; 101 } SDL_AudioCVT;
94 102
95 103
96 /* Function prototypes */ 104 /* Function prototypes */
97 105
98 /* These functions return the list of built in video drivers, in the 106 /* These functions return the list of built in video drivers, in the
99 * order that they are normally initialized by default. 107 * order that they are normally initialized by default.
100 */ 108 */
101 extern DECLSPEC int SDLCALL SDL_GetNumAudioDrivers(void); 109 extern DECLSPEC int SDLCALL SDL_GetNumAudioDrivers (void);
102 extern DECLSPEC const char * SDLCALL SDL_GetAudioDriver(int index); 110 extern DECLSPEC const char *SDLCALL SDL_GetAudioDriver (int index);
103 111
104 /* These functions are used internally, and should not be used unless you 112 /* These functions are used internally, and should not be used unless you
105 * have a specific need to specify the audio driver you want to use. 113 * have a specific need to specify the audio driver you want to use.
106 * You should normally use SDL_Init() or SDL_InitSubSystem(). 114 * You should normally use SDL_Init() or SDL_InitSubSystem().
107 */ 115 */
108 extern DECLSPEC int SDLCALL SDL_AudioInit(const char *driver_name); 116 extern DECLSPEC int SDLCALL SDL_AudioInit (const char *driver_name);
109 extern DECLSPEC void SDLCALL SDL_AudioQuit(void); 117 extern DECLSPEC void SDLCALL SDL_AudioQuit (void);
110 118
111 /* This function returns the name of the current audio driver, or NULL 119 /* This function returns the name of the current audio driver, or NULL
112 * if no driver has been initialized. 120 * if no driver has been initialized.
113 */ 121 */
114 extern DECLSPEC const char * SDLCALL SDL_GetCurrentAudioDriver(void); 122 extern DECLSPEC const char *SDLCALL SDL_GetCurrentAudioDriver (void);
115 123
116 /* 124 /*
117 * This function opens the audio device with the desired parameters, and 125 * This function opens the audio device with the desired parameters, and
118 * returns 0 if successful, placing the actual hardware parameters in the 126 * returns 0 if successful, placing the actual hardware parameters in the
119 * structure pointed to by 'obtained'. If 'obtained' is NULL, the audio 127 * structure pointed to by 'obtained'. If 'obtained' is NULL, the audio
152 * be enabled for playing by calling SDL_PauseAudio(0) when you are ready 160 * be enabled for playing by calling SDL_PauseAudio(0) when you are ready
153 * for your audio callback function to be called. Since the audio driver 161 * for your audio callback function to be called. Since the audio driver
154 * may modify the requested size of the audio buffer, you should allocate 162 * may modify the requested size of the audio buffer, you should allocate
155 * any local mixing buffers after you open the audio device. 163 * any local mixing buffers after you open the audio device.
156 */ 164 */
157 extern DECLSPEC int SDLCALL SDL_OpenAudio(SDL_AudioSpec *desired, SDL_AudioSpec *obtained); 165 extern DECLSPEC int SDLCALL SDL_OpenAudio (SDL_AudioSpec * desired,
166 SDL_AudioSpec * obtained);
158 167
159 /* 168 /*
160 * Get the current audio state: 169 * Get the current audio state:
161 */ 170 */
162 typedef enum { 171 typedef enum
163 SDL_AUDIO_STOPPED = 0, 172 {
164 SDL_AUDIO_PLAYING, 173 SDL_AUDIO_STOPPED = 0,
165 SDL_AUDIO_PAUSED 174 SDL_AUDIO_PLAYING,
175 SDL_AUDIO_PAUSED
166 } SDL_audiostatus; 176 } SDL_audiostatus;
167 extern DECLSPEC SDL_audiostatus SDLCALL SDL_GetAudioStatus(void); 177 extern DECLSPEC SDL_audiostatus SDLCALL SDL_GetAudioStatus (void);
168 178
169 /* 179 /*
170 * This function pauses and unpauses the audio callback processing. 180 * This function pauses and unpauses the audio callback processing.
171 * It should be called with a parameter of 0 after opening the audio 181 * It should be called with a parameter of 0 after opening the audio
172 * device to start playing sound. This is so you can safely initialize 182 * device to start playing sound. This is so you can safely initialize
173 * data for your callback function after opening the audio device. 183 * data for your callback function after opening the audio device.
174 * Silence will be written to the audio device during the pause. 184 * Silence will be written to the audio device during the pause.
175 */ 185 */
176 extern DECLSPEC void SDLCALL SDL_PauseAudio(int pause_on); 186 extern DECLSPEC void SDLCALL SDL_PauseAudio (int pause_on);
177 187
178 /* 188 /*
179 * This function loads a WAVE from the data source, automatically freeing 189 * This function loads a WAVE from the data source, automatically freeing
180 * that source if 'freesrc' is non-zero. For example, to load a WAVE file, 190 * that source if 'freesrc' is non-zero. For example, to load a WAVE file,
181 * you could do: 191 * you could do:
190 * 200 *
191 * This function returns NULL and sets the SDL error message if the 201 * This function returns NULL and sets the SDL error message if the
192 * wave file cannot be opened, uses an unknown data format, or is 202 * wave file cannot be opened, uses an unknown data format, or is
193 * corrupt. Currently raw and MS-ADPCM WAVE files are supported. 203 * corrupt. Currently raw and MS-ADPCM WAVE files are supported.
194 */ 204 */
195 extern DECLSPEC SDL_AudioSpec * SDLCALL SDL_LoadWAV_RW(SDL_RWops *src, int freesrc, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len); 205 extern DECLSPEC SDL_AudioSpec *SDLCALL SDL_LoadWAV_RW (SDL_RWops * src,
206 int freesrc,
207 SDL_AudioSpec * spec,
208 Uint8 ** audio_buf,
209 Uint32 * audio_len);
196 210
197 /* Compatibility convenience function -- loads a WAV from a file */ 211 /* Compatibility convenience function -- loads a WAV from a file */
198 #define SDL_LoadWAV(file, spec, audio_buf, audio_len) \ 212 #define SDL_LoadWAV(file, spec, audio_buf, audio_len) \
199 SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len) 213 SDL_LoadWAV_RW(SDL_RWFromFile(file, "rb"),1, spec,audio_buf,audio_len)
200 214
201 /* 215 /*
202 * This function frees data previously allocated with SDL_LoadWAV_RW() 216 * This function frees data previously allocated with SDL_LoadWAV_RW()
203 */ 217 */
204 extern DECLSPEC void SDLCALL SDL_FreeWAV(Uint8 *audio_buf); 218 extern DECLSPEC void SDLCALL SDL_FreeWAV (Uint8 * audio_buf);
205 219
206 /* 220 /*
207 * This function takes a source format and rate and a destination format 221 * This function takes a source format and rate and a destination format
208 * and rate, and initializes the 'cvt' structure with information needed 222 * and rate, and initializes the 'cvt' structure with information needed
209 * by SDL_ConvertAudio() to convert a buffer of audio data from one format 223 * by SDL_ConvertAudio() to convert a buffer of audio data from one format
210 * to the other. 224 * to the other.
211 * This function returns 0, or -1 if there was an error. 225 * This function returns 0, or -1 if there was an error.
212 */ 226 */
213 extern DECLSPEC int SDLCALL SDL_BuildAudioCVT(SDL_AudioCVT *cvt, 227 extern DECLSPEC int SDLCALL SDL_BuildAudioCVT (SDL_AudioCVT * cvt,
214 Uint16 src_format, Uint8 src_channels, int src_rate, 228 Uint16 src_format,
215 Uint16 dst_format, Uint8 dst_channels, int dst_rate); 229 Uint8 src_channels,
230 int src_rate,
231 Uint16 dst_format,
232 Uint8 dst_channels,
233 int dst_rate);
216 234
217 /* Once you have initialized the 'cvt' structure using SDL_BuildAudioCVT(), 235 /* Once you have initialized the 'cvt' structure using SDL_BuildAudioCVT(),
218 * created an audio buffer cvt->buf, and filled it with cvt->len bytes of 236 * created an audio buffer cvt->buf, and filled it with cvt->len bytes of
219 * audio data in the source format, this function will convert it in-place 237 * audio data in the source format, this function will convert it in-place
220 * to the desired format. 238 * to the desired format.
221 * The data conversion may expand the size of the audio data, so the buffer 239 * The data conversion may expand the size of the audio data, so the buffer
222 * cvt->buf should be allocated after the cvt structure is initialized by 240 * cvt->buf should be allocated after the cvt structure is initialized by
223 * SDL_BuildAudioCVT(), and should be cvt->len*cvt->len_mult bytes long. 241 * SDL_BuildAudioCVT(), and should be cvt->len*cvt->len_mult bytes long.
224 */ 242 */
225 extern DECLSPEC int SDLCALL SDL_ConvertAudio(SDL_AudioCVT *cvt); 243 extern DECLSPEC int SDLCALL SDL_ConvertAudio (SDL_AudioCVT * cvt);
226 244
227 /* 245 /*
228 * This takes two audio buffers of the playing audio format and mixes 246 * This takes two audio buffers of the playing audio format and mixes
229 * them, performing addition, volume adjustment, and overflow clipping. 247 * them, performing addition, volume adjustment, and overflow clipping.
230 * The volume ranges from 0 - 128, and should be set to SDL_MIX_MAXVOLUME 248 * The volume ranges from 0 - 128, and should be set to SDL_MIX_MAXVOLUME
231 * for full audio volume. Note this does not change hardware volume. 249 * for full audio volume. Note this does not change hardware volume.
232 * This is provided for convenience -- you can mix your own audio data. 250 * This is provided for convenience -- you can mix your own audio data.
233 */ 251 */
234 #define SDL_MIX_MAXVOLUME 128 252 #define SDL_MIX_MAXVOLUME 128
235 extern DECLSPEC void SDLCALL SDL_MixAudio(Uint8 *dst, const Uint8 *src, Uint32 len, int volume); 253 extern DECLSPEC void SDLCALL SDL_MixAudio (Uint8 * dst, const Uint8 * src,
254 Uint32 len, int volume);
236 255
237 /* 256 /*
238 * The lock manipulated by these functions protects the callback function. 257 * The lock manipulated by these functions protects the callback function.
239 * During a LockAudio/UnlockAudio pair, you can be guaranteed that the 258 * During a LockAudio/UnlockAudio pair, you can be guaranteed that the
240 * callback function is not running. Do not call these from the callback 259 * callback function is not running. Do not call these from the callback
241 * function or you will cause deadlock. 260 * function or you will cause deadlock.
242 */ 261 */
243 extern DECLSPEC void SDLCALL SDL_LockAudio(void); 262 extern DECLSPEC void SDLCALL SDL_LockAudio (void);
244 extern DECLSPEC void SDLCALL SDL_UnlockAudio(void); 263 extern DECLSPEC void SDLCALL SDL_UnlockAudio (void);
245 264
246 /* 265 /*
247 * This function shuts down audio processing and closes the audio device. 266 * This function shuts down audio processing and closes the audio device.
248 */ 267 */
249 extern DECLSPEC void SDLCALL SDL_CloseAudio(void); 268 extern DECLSPEC void SDLCALL SDL_CloseAudio (void);
250 269
251 270
252 /* Ends C function definitions when using C++ */ 271 /* Ends C function definitions when using C++ */
253 #ifdef __cplusplus 272 #ifdef __cplusplus
273 /* *INDENT-OFF* */
254 } 274 }
275 /* *INDENT-ON* */
255 #endif 276 #endif
256 #include "close_code.h" 277 #include "close_code.h"
257 278
258 #endif /* _SDL_audio_h */ 279 #endif /* _SDL_audio_h */
280
281 /* vi: set ts=4 sw=4 expandtab: */