Mercurial > sdl-ios-xcode
annotate src/audio/dma/SDL_dmaaudio.c @ 175:0fb1328d68c2
Fix for "make dist"
author | Sam Lantinga <slouken@libsdl.org> |
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date | Tue, 11 Sep 2001 20:49:27 +0000 |
parents | ae6e6b73333f |
children | e8157fcb3114 |
rev | line source |
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0 | 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 "@(#) $Id$"; | |
26 #endif | |
27 | |
28 /* Allow access to a raw mixing buffer */ | |
29 | |
30 #include <stdlib.h> | |
31 #include <stdio.h> | |
32 #include <string.h> | |
33 #include <errno.h> | |
34 #include <unistd.h> | |
35 #include <fcntl.h> | |
36 #include <signal.h> | |
37 #include <sys/types.h> | |
38 #include <sys/time.h> | |
39 #include <sys/ioctl.h> | |
40 #include <sys/stat.h> | |
41 #include <sys/mman.h> | |
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42 #ifdef OSS_USE_SOUNDCARD_H |
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43 /* This is installed on some systems */ |
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44 #include <soundcard.h> |
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45 #else |
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46 /* This is recommended by OSS */ |
0 | 47 #include <sys/soundcard.h> |
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48 #endif |
0 | 49 |
50 #ifndef MAP_FAILED | |
51 #define MAP_FAILED ((Uint8 *)-1) | |
52 #endif | |
53 | |
54 #include "SDL_audio.h" | |
55 #include "SDL_error.h" | |
56 #include "SDL_audiomem.h" | |
57 #include "SDL_audio_c.h" | |
58 #include "SDL_timer.h" | |
59 #include "SDL_audiodev_c.h" | |
60 #include "SDL_dmaaudio.h" | |
61 | |
62 /* The tag name used by DMA audio */ | |
63 #define DMA_DRIVER_NAME "dma" | |
64 | |
65 /* Open the audio device for playback, and don't block if busy */ | |
66 #define OPEN_FLAGS (O_RDWR|O_NONBLOCK) | |
67 | |
68 /* Audio driver functions */ | |
69 static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec); | |
70 static void DMA_WaitAudio(_THIS); | |
71 static void DMA_PlayAudio(_THIS); | |
72 static Uint8 *DMA_GetAudioBuf(_THIS); | |
73 static void DMA_CloseAudio(_THIS); | |
74 | |
75 /* Audio driver bootstrap functions */ | |
76 | |
77 static int Audio_Available(void) | |
78 { | |
79 int available; | |
80 int fd; | |
81 | |
82 available = 0; | |
83 | |
84 fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0); | |
85 if ( fd >= 0 ) { | |
86 int caps; | |
87 struct audio_buf_info info; | |
88 | |
89 if ( (ioctl(fd, SNDCTL_DSP_GETCAPS, &caps) == 0) && | |
90 (caps & DSP_CAP_TRIGGER) && (caps & DSP_CAP_MMAP) && | |
91 (ioctl(fd, SNDCTL_DSP_GETOSPACE, &info) == 0) ) { | |
92 available = 1; | |
93 } | |
94 close(fd); | |
95 } | |
96 return(available); | |
97 } | |
98 | |
99 static void Audio_DeleteDevice(SDL_AudioDevice *device) | |
100 { | |
101 free(device->hidden); | |
102 free(device); | |
103 } | |
104 | |
105 static SDL_AudioDevice *Audio_CreateDevice(int devindex) | |
106 { | |
107 SDL_AudioDevice *this; | |
108 | |
109 /* Initialize all variables that we clean on shutdown */ | |
110 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice)); | |
111 if ( this ) { | |
112 memset(this, 0, (sizeof *this)); | |
113 this->hidden = (struct SDL_PrivateAudioData *) | |
114 malloc((sizeof *this->hidden)); | |
115 } | |
116 if ( (this == NULL) || (this->hidden == NULL) ) { | |
117 SDL_OutOfMemory(); | |
118 if ( this ) { | |
119 free(this); | |
120 } | |
121 return(0); | |
122 } | |
123 memset(this->hidden, 0, (sizeof *this->hidden)); | |
124 audio_fd = -1; | |
125 | |
126 /* Set the function pointers */ | |
127 this->OpenAudio = DMA_OpenAudio; | |
128 this->WaitAudio = DMA_WaitAudio; | |
129 this->PlayAudio = DMA_PlayAudio; | |
130 this->GetAudioBuf = DMA_GetAudioBuf; | |
131 this->CloseAudio = DMA_CloseAudio; | |
132 | |
133 this->free = Audio_DeleteDevice; | |
134 | |
135 return this; | |
136 } | |
137 | |
138 AudioBootStrap DMA_bootstrap = { | |
139 DMA_DRIVER_NAME, "OSS /dev/dsp DMA audio", | |
140 Audio_Available, Audio_CreateDevice | |
141 }; | |
142 | |
143 /* This function waits until it is possible to write a full sound buffer */ | |
144 static void DMA_WaitAudio(_THIS) | |
145 { | |
146 fd_set fdset; | |
147 | |
148 /* Check to see if the thread-parent process is still alive */ | |
149 { static int cnt = 0; | |
150 /* Note that this only works with thread implementations | |
151 that use a different process id for each thread. | |
152 */ | |
153 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ | |
154 if ( kill(parent, 0) < 0 ) { | |
155 this->enabled = 0; | |
156 } | |
157 } | |
158 } | |
159 | |
160 /* See if we need to use timed audio synchronization */ | |
161 if ( frame_ticks ) { | |
162 /* Use timer for general audio synchronization */ | |
163 Sint32 ticks; | |
164 | |
165 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; | |
166 if ( ticks > 0 ) { | |
167 SDL_Delay(ticks); | |
168 } | |
169 } else { | |
170 /* Use select() for audio synchronization */ | |
171 struct timeval timeout; | |
172 FD_ZERO(&fdset); | |
173 FD_SET(audio_fd, &fdset); | |
174 timeout.tv_sec = 10; | |
175 timeout.tv_usec = 0; | |
176 #ifdef DEBUG_AUDIO | |
177 fprintf(stderr, "Waiting for audio to get ready\n"); | |
178 #endif | |
179 if ( select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0 ) { | |
180 const char *message = | |
181 #ifdef AUDIO_OSPACE_HACK | |
182 "Audio timeout - buggy audio driver? (trying ospace)"; | |
183 #else | |
184 "Audio timeout - buggy audio driver? (disabled)"; | |
185 #endif | |
186 /* In general we should never print to the screen, | |
187 but in this case we have no other way of letting | |
188 the user know what happened. | |
189 */ | |
190 fprintf(stderr, "SDL: %s\n", message); | |
191 #ifdef AUDIO_OSPACE_HACK | |
192 /* We may be able to use GET_OSPACE trick */ | |
193 frame_ticks = (float)(this->spec->samples*1000) / | |
194 this->spec->freq; | |
195 next_frame = SDL_GetTicks()+frame_ticks; | |
196 #else | |
197 this->enabled = 0; | |
198 /* Don't try to close - may hang */ | |
199 audio_fd = -1; | |
200 #ifdef DEBUG_AUDIO | |
201 fprintf(stderr, "Done disabling audio\n"); | |
202 #endif | |
203 #endif /* AUDIO_OSPACE_HACK */ | |
204 } | |
205 #ifdef DEBUG_AUDIO | |
206 fprintf(stderr, "Ready!\n"); | |
207 #endif | |
208 } | |
209 } | |
210 | |
211 static void DMA_PlayAudio(_THIS) | |
212 { | |
213 /* If timer synchronization is enabled, set the next write frame */ | |
214 if ( frame_ticks ) { | |
215 next_frame += frame_ticks; | |
216 } | |
217 return; | |
218 } | |
219 | |
220 static Uint8 *DMA_GetAudioBuf(_THIS) | |
221 { | |
222 count_info info; | |
223 int playing; | |
224 int filling; | |
225 | |
226 /* Get number of blocks, looping if we're not using select() */ | |
227 do { | |
228 if ( ioctl(audio_fd, SNDCTL_DSP_GETOPTR, &info) < 0 ) { | |
229 /* Uh oh... */ | |
230 this->enabled = 0; | |
231 return(NULL); | |
232 } | |
233 } while ( frame_ticks && (info.blocks < 1) ); | |
234 #ifdef DEBUG_AUDIO | |
235 if ( info.blocks > 1 ) { | |
236 printf("Warning: audio underflow (%d frags)\n", info.blocks-1); | |
237 } | |
238 #endif | |
239 playing = info.ptr / this->spec.size; | |
240 filling = (playing + 1)%num_buffers; | |
241 return (dma_buf + (filling * this->spec.size)); | |
242 } | |
243 | |
244 static void DMA_CloseAudio(_THIS) | |
245 { | |
246 if ( dma_buf != NULL ) { | |
247 munmap(dma_buf, dma_len); | |
248 dma_buf = NULL; | |
249 } | |
250 if ( audio_fd >= 0 ) { | |
251 close(audio_fd); | |
252 audio_fd = -1; | |
253 } | |
254 } | |
255 | |
256 static int DMA_ReopenAudio(_THIS, const char *audiodev, int format, int stereo, | |
257 SDL_AudioSpec *spec) | |
258 { | |
259 int frag_spec; | |
260 int value; | |
261 | |
262 /* Close and then reopen the audio device */ | |
263 close(audio_fd); | |
264 audio_fd = open(audiodev, O_RDWR, 0); | |
265 if ( audio_fd < 0 ) { | |
266 SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); | |
267 return(-1); | |
268 } | |
269 | |
270 /* Calculate the final parameters for this audio specification */ | |
271 SDL_CalculateAudioSpec(spec); | |
272 | |
273 /* Determine the power of two of the fragment size */ | |
274 for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec ); | |
275 if ( (0x01<<frag_spec) != spec->size ) { | |
276 SDL_SetError("Fragment size must be a power of two"); | |
277 return(-1); | |
278 } | |
279 | |
280 /* Set the audio buffering parameters */ | |
281 if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) { | |
282 SDL_SetError("Couldn't set audio fragment spec"); | |
283 return(-1); | |
284 } | |
285 | |
286 /* Set the audio format */ | |
287 value = format; | |
288 if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || | |
289 (value != format) ) { | |
290 SDL_SetError("Couldn't set audio format"); | |
291 return(-1); | |
292 } | |
293 | |
294 /* Set mono or stereo audio */ | |
295 value = (spec->channels > 1); | |
296 if ( (ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo) < 0) || | |
297 (value != stereo) ) { | |
298 SDL_SetError("Couldn't set audio channels"); | |
299 return(-1); | |
300 } | |
301 | |
302 /* Set the DSP frequency */ | |
303 value = spec->freq; | |
304 if ( ioctl(audio_fd, SOUND_PCM_WRITE_RATE, &value) < 0 ) { | |
305 SDL_SetError("Couldn't set audio frequency"); | |
306 return(-1); | |
307 } | |
308 spec->freq = value; | |
309 | |
310 /* We successfully re-opened the audio */ | |
311 return(0); | |
312 } | |
313 | |
314 static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec) | |
315 { | |
316 char audiodev[1024]; | |
317 int format; | |
318 int stereo; | |
319 int value; | |
320 Uint16 test_format; | |
321 struct audio_buf_info info; | |
322 | |
323 /* Reset the timer synchronization flag */ | |
324 frame_ticks = 0.0; | |
325 | |
326 /* Open the audio device */ | |
327 audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0); | |
328 if ( audio_fd < 0 ) { | |
329 SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); | |
330 return(-1); | |
331 } | |
332 dma_buf = NULL; | |
333 ioctl(audio_fd, SNDCTL_DSP_RESET, 0); | |
334 | |
335 /* Get a list of supported hardware formats */ | |
336 if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) { | |
337 SDL_SetError("Couldn't get audio format list"); | |
338 return(-1); | |
339 } | |
340 | |
341 /* Try for a closest match on audio format */ | |
342 format = 0; | |
343 for ( test_format = SDL_FirstAudioFormat(spec->format); | |
344 ! format && test_format; ) { | |
345 #ifdef DEBUG_AUDIO | |
346 fprintf(stderr, "Trying format 0x%4.4x\n", test_format); | |
347 #endif | |
348 switch ( test_format ) { | |
349 case AUDIO_U8: | |
350 if ( value & AFMT_U8 ) { | |
351 format = AFMT_U8; | |
352 } | |
353 break; | |
354 case AUDIO_S8: | |
355 if ( value & AFMT_S8 ) { | |
356 format = AFMT_S8; | |
357 } | |
358 break; | |
359 case AUDIO_S16LSB: | |
360 if ( value & AFMT_S16_LE ) { | |
361 format = AFMT_S16_LE; | |
362 } | |
363 break; | |
364 case AUDIO_S16MSB: | |
365 if ( value & AFMT_S16_BE ) { | |
366 format = AFMT_S16_BE; | |
367 } | |
368 break; | |
369 case AUDIO_U16LSB: | |
370 if ( value & AFMT_U16_LE ) { | |
371 format = AFMT_U16_LE; | |
372 } | |
373 break; | |
374 case AUDIO_U16MSB: | |
375 if ( value & AFMT_U16_BE ) { | |
376 format = AFMT_U16_BE; | |
377 } | |
378 break; | |
379 default: | |
380 break; | |
381 } | |
382 if ( ! format ) { | |
383 test_format = SDL_NextAudioFormat(); | |
384 } | |
385 } | |
386 if ( format == 0 ) { | |
387 SDL_SetError("Couldn't find any hardware audio formats"); | |
388 return(-1); | |
389 } | |
390 spec->format = test_format; | |
391 | |
392 /* Set the audio format */ | |
393 value = format; | |
394 if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || | |
395 (value != format) ) { | |
396 SDL_SetError("Couldn't set audio format"); | |
397 return(-1); | |
398 } | |
399 | |
400 /* Set mono or stereo audio (currently only two channels supported) */ | |
401 stereo = (spec->channels > 1); | |
402 ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo); | |
403 if ( stereo ) { | |
404 spec->channels = 2; | |
405 } else { | |
406 spec->channels = 1; | |
407 } | |
408 | |
409 /* Because some drivers don't allow setting the buffer size | |
410 after setting the format, we must re-open the audio device | |
411 once we know what format and channels are supported | |
412 */ | |
413 if ( DMA_ReopenAudio(this, audiodev, format, stereo, spec) < 0 ) { | |
414 /* Error is set by DMA_ReopenAudio() */ | |
415 return(-1); | |
416 } | |
417 | |
418 /* Memory map the audio buffer */ | |
419 if ( ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info) < 0 ) { | |
420 SDL_SetError("Couldn't get OSPACE parameters"); | |
421 return(-1); | |
422 } | |
423 spec->size = info.fragsize; | |
424 spec->samples = spec->size / ((spec->format & 0xFF) / 8); | |
425 spec->samples /= spec->channels; | |
426 num_buffers = info.fragstotal; | |
427 dma_len = num_buffers*spec->size; | |
428 dma_buf = (Uint8 *)mmap(NULL, dma_len, PROT_WRITE, MAP_SHARED, | |
429 audio_fd, 0); | |
430 if ( dma_buf == MAP_FAILED ) { | |
431 SDL_SetError("DMA memory map failed"); | |
432 dma_buf = NULL; | |
433 return(-1); | |
434 } | |
435 memset(dma_buf, spec->silence, dma_len); | |
436 | |
437 /* Check to see if we need to use select() workaround */ | |
438 { char *workaround; | |
439 workaround = getenv("SDL_DSP_NOSELECT"); | |
440 if ( workaround ) { | |
441 frame_ticks = (float)(spec->samples*1000)/spec->freq; | |
442 next_frame = SDL_GetTicks()+frame_ticks; | |
443 } | |
444 } | |
445 | |
446 /* Trigger audio playback */ | |
447 value = 0; | |
448 ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value); | |
449 value = PCM_ENABLE_OUTPUT; | |
450 if ( ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value) < 0 ) { | |
451 SDL_SetError("Couldn't trigger audio output"); | |
452 return(-1); | |
453 } | |
454 | |
455 /* Get the parent process id (we're the parent of the audio thread) */ | |
456 parent = getpid(); | |
457 | |
458 /* We're ready to rock and roll. :-) */ | |
459 return(0); | |
460 } |