src/audio/windib/SDL_dibaudio.c
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FUNCTIONS
This source file includes following functions.
- Audio_Available
- Audio_DeleteDevice
- Audio_CreateDevice
- FillSound
- SetMMerror
- DIB_ThreadInit
- DIB_WaitAudio
- DIB_GetAudioBuf
- DIB_PlayAudio
- DIB_WaitDone
- DIB_CloseAudio
- DIB_OpenAudio
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
14
15 You should have received a copy of the GNU Library General Public
16 License along with this library; if not, write to the Free
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 Sam Lantinga
20 slouken@devolution.com
21 */
22
23 #ifdef SAVE_RCSID
24 static char rcsid =
25 "@(#) $Id: SDL_dibaudio.c,v 1.1.2.2 2001/02/10 07:20:03 hercules Exp $";
26 #endif
27
28 /* Allow access to a raw mixing buffer */
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <windows.h>
33 #include <mmsystem.h>
34
35 #include "SDL_audio.h"
36 #include "SDL_mutex.h"
37 #include "SDL_timer.h"
38 #include "SDL_audio_c.h"
39 #include "SDL_dibaudio.h"
40
41
42 /* Audio driver functions */
43 static int DIB_OpenAudio(_THIS, SDL_AudioSpec *spec);
44 static void DIB_ThreadInit(_THIS);
45 static void DIB_WaitAudio(_THIS);
46 static Uint8 *DIB_GetAudioBuf(_THIS);
47 static void DIB_PlayAudio(_THIS);
48 static void DIB_WaitDone(_THIS);
49 static void DIB_CloseAudio(_THIS);
50
51 /* Audio driver bootstrap functions */
52
53 static int Audio_Available(void)
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54 {
55 return(1);
56 }
57
58 static void Audio_DeleteDevice(SDL_AudioDevice *device)
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59 {
60 free(device->hidden);
61 free(device);
62 }
63
64 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
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65 {
66 SDL_AudioDevice *this;
67
68 /* Initialize all variables that we clean on shutdown */
69 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
70 if ( this ) {
71 memset(this, 0, (sizeof *this));
72 this->hidden = (struct SDL_PrivateAudioData *)
73 malloc((sizeof *this->hidden));
74 }
75 if ( (this == NULL) || (this->hidden == NULL) ) {
76 SDL_OutOfMemory();
77 if ( this ) {
78 free(this);
79 }
80 return(0);
81 }
82 memset(this->hidden, 0, (sizeof *this->hidden));
83
84 /* Set the function pointers */
85 this->OpenAudio = DIB_OpenAudio;
86 this->ThreadInit = DIB_ThreadInit;
87 this->WaitAudio = DIB_WaitAudio;
88 this->PlayAudio = DIB_PlayAudio;
89 this->GetAudioBuf = DIB_GetAudioBuf;
90 this->WaitDone = DIB_WaitDone;
91 this->CloseAudio = DIB_CloseAudio;
92
93 this->free = Audio_DeleteDevice;
94
95 return this;
96 }
97
98 AudioBootStrap WAVEOUT_bootstrap = {
99 "waveout", "Win95/98/NT/2000 WaveOut",
100 Audio_Available, Audio_CreateDevice
101 };
102
103
104 /* The Win32 callback for filling the WAVE device */
105 static void CALLBACK FillSound(HWAVEOUT hwo, UINT uMsg, DWORD dwInstance,
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106 DWORD dwParam1, DWORD dwParam2)
107 {
108 SDL_AudioDevice *this = (SDL_AudioDevice *)dwInstance;
109
110 /* Only service "buffer done playing" messages */
111 if ( uMsg != WOM_DONE )
112 return;
113
114 /* Signal that we are done playing a buffer */
115 ReleaseSemaphore(audio_sem, 1, NULL);
116 }
117
118 static void SetMMerror(char *function, MMRESULT code)
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119 {
120 int len;
121 char errbuf[MAXERRORLENGTH];
122
123 sprintf(errbuf, "%s: ", function);
124 len = strlen(errbuf);
125 waveOutGetErrorText(code, errbuf+len, MAXERRORLENGTH-len);
126 SDL_SetError("%s", errbuf);
127 }
128
129 /* Set high priority for the audio thread */
130 static void DIB_ThreadInit(_THIS)
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131 {
132 SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
133 }
134
135 void DIB_WaitAudio(_THIS)
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136 {
137 /* Wait for an audio chunk to finish */
138 WaitForSingleObject(audio_sem, INFINITE);
139 }
140
141 Uint8 *DIB_GetAudioBuf(_THIS)
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142 {
143 Uint8 *retval;
144
145 retval = (Uint8 *)(wavebuf[next_buffer].lpData);
146 return retval;
147 }
148
149 void DIB_PlayAudio(_THIS)
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150 {
151 /* Queue it up */
152 waveOutWrite(sound, &wavebuf[next_buffer], sizeof(wavebuf[0]));
153 next_buffer = (next_buffer+1)%NUM_BUFFERS;
154 }
155
156 void DIB_WaitDone(_THIS)
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157 {
158 int i, left;
159
160 do {
161 left = NUM_BUFFERS;
162 for ( i=0; i<NUM_BUFFERS; ++i ) {
163 if ( wavebuf[i].dwFlags & WHDR_DONE ) {
164 --left;
165 }
166 }
167 if ( left > 0 ) {
168 SDL_Delay(100);
169 }
170 } while ( left > 0 );
171 }
172
173 void DIB_CloseAudio(_THIS)
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174 {
175 int i;
176
177 /* Close up audio */
178 if ( audio_sem ) {
179 CloseHandle(audio_sem);
180 }
181 if ( sound ) {
182 waveOutClose(sound);
183 }
184
185 /* Clean up mixing buffers */
186 for ( i=0; i<NUM_BUFFERS; ++i ) {
187 if ( wavebuf[i].dwUser != 0xFFFF ) {
188 waveOutUnprepareHeader(sound, &wavebuf[i],
189 sizeof(wavebuf[i]));
190 wavebuf[i].dwUser = 0xFFFF;
191 }
192 }
193 /* Free raw mixing buffer */
194 if ( mixbuf != NULL ) {
195 free(mixbuf);
196 mixbuf = NULL;
197 }
198 }
199
200 int DIB_OpenAudio(_THIS, SDL_AudioSpec *spec)
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201 {
202 MMRESULT result;
203 int i;
204 WAVEFORMATEX waveformat;
205
206 /* Initialize the wavebuf structures for closing */
207 sound = NULL;
208 audio_sem = NULL;
209 for ( i = 0; i < NUM_BUFFERS; ++i )
210 wavebuf[i].dwUser = 0xFFFF;
211 mixbuf = NULL;
212
213 /* Set basic WAVE format parameters */
214 memset(&waveformat, 0, sizeof(waveformat));
215 waveformat.wFormatTag = WAVE_FORMAT_PCM;
216
217 /* Determine the audio parameters from the AudioSpec */
218 switch ( spec->format & 0xFF ) {
219 case 8:
220 /* Unsigned 8 bit audio data */
221 spec->format = AUDIO_U8;
222 waveformat.wBitsPerSample = 8;
223 break;
224 case 16:
225 /* Signed 16 bit audio data */
226 spec->format = AUDIO_S16;
227 waveformat.wBitsPerSample = 16;
228 break;
229 default:
230 SDL_SetError("Unsupported audio format");
231 return(-1);
232 }
233 waveformat.nChannels = spec->channels;
234 waveformat.nSamplesPerSec = spec->freq;
235 waveformat.nBlockAlign =
236 waveformat.nChannels * (waveformat.wBitsPerSample/8);
237 waveformat.nAvgBytesPerSec =
238 waveformat.nSamplesPerSec * waveformat.nBlockAlign;
239
240 /* Check the buffer size -- minimum of 1/4 second (word aligned) */
241 if ( spec->samples < (spec->freq/4) )
242 spec->samples = ((spec->freq/4)+3)&~3;
243
244 /* Update the fragment size as size in bytes */
245 SDL_CalculateAudioSpec(spec);
246
247 /* Open the audio device */
248 result = waveOutOpen(&sound, WAVE_MAPPER, &waveformat,
249 (DWORD)FillSound, (DWORD)this, CALLBACK_FUNCTION);
250 if ( result != MMSYSERR_NOERROR ) {
251 SetMMerror("waveOutOpen()", result);
252 return(-1);
253 }
254
255 #ifdef SOUND_DEBUG
256 /* Check the sound device we retrieved */
257 {
258 WAVEOUTCAPS caps;
259
260 result = waveOutGetDevCaps((UINT)sound, &caps, sizeof(caps));
261 if ( result != MMSYSERR_NOERROR ) {
262 SetMMerror("waveOutGetDevCaps()", result);
263 return(-1);
264 }
265 printf("Audio device: %s\n", caps.szPname);
266 }
267 #endif
268
269 /* Create the audio buffer semaphore */
270 audio_sem = CreateSemaphore(NULL, NUM_BUFFERS-1, NUM_BUFFERS, NULL);
271 if ( audio_sem == NULL ) {
272 SDL_SetError("Couldn't create semaphore");
273 return(-1);
274 }
275
276 /* Create the sound buffers */
277 mixbuf = (Uint8 *)malloc(NUM_BUFFERS*spec->size);
278 if ( mixbuf == NULL ) {
279 SDL_SetError("Out of memory");
280 return(-1);
281 }
282 for ( i = 0; i < NUM_BUFFERS; ++i ) {
283 memset(&wavebuf[i], 0, sizeof(wavebuf[i]));
284 wavebuf[i].lpData = (LPSTR) &mixbuf[i*spec->size];
285 wavebuf[i].dwBufferLength = spec->size;
286 wavebuf[i].dwFlags = WHDR_DONE;
287 result = waveOutPrepareHeader(sound, &wavebuf[i],
288 sizeof(wavebuf[i]));
289 if ( result != MMSYSERR_NOERROR ) {
290 SetMMerror("waveOutPrepareHeader()", result);
291 return(-1);
292 }
293 }
294
295 /* Ready to go! */
296 next_buffer = 0;
297 return(0);
298 }