e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 Sam Lantinga |
4 | |
5 | This library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 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 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with this library; if not, write to the Free Software |
17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
18 | |
19 | Sam Lantinga |
20 | slouken@libsdl.org |
21 | */ |
22 | #include "SDL_config.h" |
23 | |
24 | /* Allow access to a raw mixing buffer */ |
25 | |
26 | #include <stdio.h> |
27 | #include <string.h> /* For strerror() */ |
28 | #include <errno.h> |
29 | #include <unistd.h> |
30 | #include <fcntl.h> |
31 | #include <signal.h> |
32 | #include <sys/types.h> |
33 | #include <sys/time.h> |
34 | #include <sys/ioctl.h> |
35 | #include <sys/stat.h> |
36 | #include <sys/mman.h> |
37 | |
38 | #if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H |
39 | /* This is installed on some systems */ |
40 | #include <soundcard.h> |
41 | #else |
42 | /* This is recommended by OSS */ |
43 | #include <sys/soundcard.h> |
44 | #endif |
45 | |
46 | #ifndef MAP_FAILED |
47 | #define MAP_FAILED ((Uint8 *)-1) |
48 | #endif |
49 | |
50 | #include "SDL_timer.h" |
51 | #include "SDL_audio.h" |
52 | #include "../SDL_audio_c.h" |
53 | #include "../SDL_audiodev_c.h" |
54 | #include "SDL_dmaaudio.h" |
55 | |
56 | /* The tag name used by DMA audio */ |
57 | #define DMA_DRIVER_NAME "dma" |
58 | |
59 | /* Open the audio device for playback, and don't block if busy */ |
60 | #define OPEN_FLAGS (O_RDWR|O_NONBLOCK) |
61 | |
62 | /* Audio driver functions */ |
63 | static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec); |
64 | static void DMA_WaitAudio(_THIS); |
65 | static void DMA_PlayAudio(_THIS); |
66 | static Uint8 *DMA_GetAudioBuf(_THIS); |
67 | static void DMA_CloseAudio(_THIS); |
68 | |
69 | /* Audio driver bootstrap functions */ |
70 | |
71 | static int Audio_Available(void) |
72 | { |
73 | int available; |
74 | int fd; |
75 | |
76 | available = 0; |
77 | |
78 | fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0); |
79 | if ( fd >= 0 ) { |
80 | int caps; |
81 | struct audio_buf_info info; |
82 | |
83 | if ( (ioctl(fd, SNDCTL_DSP_GETCAPS, &caps) == 0) && |
84 | (caps & DSP_CAP_TRIGGER) && (caps & DSP_CAP_MMAP) && |
85 | (ioctl(fd, SNDCTL_DSP_GETOSPACE, &info) == 0) ) { |
86 | available = 1; |
87 | } |
88 | close(fd); |
89 | } |
90 | return(available); |
91 | } |
92 | |
93 | static void Audio_DeleteDevice(SDL_AudioDevice *device) |
94 | { |
95 | SDL_free(device->hidden); |
96 | SDL_free(device); |
97 | } |
98 | |
99 | static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
100 | { |
101 | SDL_AudioDevice *this; |
102 | |
103 | /* Initialize all variables that we clean on shutdown */ |
104 | this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); |
105 | if ( this ) { |
106 | SDL_memset(this, 0, (sizeof *this)); |
107 | this->hidden = (struct SDL_PrivateAudioData *) |
108 | SDL_malloc((sizeof *this->hidden)); |
109 | } |
110 | if ( (this == NULL) || (this->hidden == NULL) ) { |
111 | SDL_OutOfMemory(); |
112 | if ( this ) { |
113 | SDL_free(this); |
114 | } |
115 | return(0); |
116 | } |
117 | SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
118 | audio_fd = -1; |
119 | |
120 | /* Set the function pointers */ |
121 | this->OpenAudio = DMA_OpenAudio; |
122 | this->WaitAudio = DMA_WaitAudio; |
123 | this->PlayAudio = DMA_PlayAudio; |
124 | this->GetAudioBuf = DMA_GetAudioBuf; |
125 | this->CloseAudio = DMA_CloseAudio; |
126 | |
127 | this->free = Audio_DeleteDevice; |
128 | |
129 | return this; |
130 | } |
131 | |
132 | AudioBootStrap DMA_bootstrap = { |
133 | DMA_DRIVER_NAME, "OSS /dev/dsp DMA audio", |
134 | Audio_Available, Audio_CreateDevice |
135 | }; |
136 | |
137 | /* This function waits until it is possible to write a full sound buffer */ |
138 | static void DMA_WaitAudio(_THIS) |
139 | { |
140 | fd_set fdset; |
141 | |
142 | /* Check to see if the thread-parent process is still alive */ |
143 | { static int cnt = 0; |
144 | /* Note that this only works with thread implementations |
145 | that use a different process id for each thread. |
146 | */ |
147 | if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ |
148 | if ( kill(parent, 0) < 0 ) { |
149 | this->enabled = 0; |
150 | } |
151 | } |
152 | } |
153 | |
154 | /* See if we need to use timed audio synchronization */ |
155 | if ( frame_ticks ) { |
156 | /* Use timer for general audio synchronization */ |
157 | Sint32 ticks; |
158 | |
159 | ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; |
160 | if ( ticks > 0 ) { |
161 | SDL_Delay(ticks); |
162 | } |
163 | } else { |
164 | /* Use select() for audio synchronization */ |
165 | struct timeval timeout; |
166 | FD_ZERO(&fdset); |
167 | FD_SET(audio_fd, &fdset); |
168 | timeout.tv_sec = 10; |
169 | timeout.tv_usec = 0; |
170 | #ifdef DEBUG_AUDIO |
171 | fprintf(stderr, "Waiting for audio to get ready\n"); |
172 | #endif |
173 | if ( select(audio_fd+1, NULL, &fdset, NULL, &timeout) <= 0 ) { |
174 | const char *message = |
175 | #ifdef AUDIO_OSPACE_HACK |
176 | "Audio timeout - buggy audio driver? (trying ospace)"; |
177 | #else |
178 | "Audio timeout - buggy audio driver? (disabled)"; |
179 | #endif |
180 | /* In general we should never print to the screen, |
181 | but in this case we have no other way of letting |
182 | the user know what happened. |
183 | */ |
184 | fprintf(stderr, "SDL: %s\n", message); |
185 | #ifdef AUDIO_OSPACE_HACK |
186 | /* We may be able to use GET_OSPACE trick */ |
187 | frame_ticks = (float)(this->spec->samples*1000) / |
188 | this->spec->freq; |
189 | next_frame = SDL_GetTicks()+frame_ticks; |
190 | #else |
191 | this->enabled = 0; |
192 | /* Don't try to close - may hang */ |
193 | audio_fd = -1; |
194 | #ifdef DEBUG_AUDIO |
195 | fprintf(stderr, "Done disabling audio\n"); |
196 | #endif |
197 | #endif /* AUDIO_OSPACE_HACK */ |
198 | } |
199 | #ifdef DEBUG_AUDIO |
200 | fprintf(stderr, "Ready!\n"); |
201 | #endif |
202 | } |
203 | } |
204 | |
205 | static void DMA_PlayAudio(_THIS) |
206 | { |
207 | /* If timer synchronization is enabled, set the next write frame */ |
208 | if ( frame_ticks ) { |
209 | next_frame += frame_ticks; |
210 | } |
211 | return; |
212 | } |
213 | |
214 | static Uint8 *DMA_GetAudioBuf(_THIS) |
215 | { |
216 | count_info info; |
217 | int playing; |
218 | int filling; |
219 | |
220 | /* Get number of blocks, looping if we're not using select() */ |
221 | do { |
222 | if ( ioctl(audio_fd, SNDCTL_DSP_GETOPTR, &info) < 0 ) { |
223 | /* Uh oh... */ |
224 | this->enabled = 0; |
225 | return(NULL); |
226 | } |
227 | } while ( frame_ticks && (info.blocks < 1) ); |
228 | #ifdef DEBUG_AUDIO |
229 | if ( info.blocks > 1 ) { |
230 | printf("Warning: audio underflow (%d frags)\n", info.blocks-1); |
231 | } |
232 | #endif |
233 | playing = info.ptr / this->spec.size; |
234 | filling = (playing + 1)%num_buffers; |
235 | return (dma_buf + (filling * this->spec.size)); |
236 | } |
237 | |
238 | static void DMA_CloseAudio(_THIS) |
239 | { |
240 | if ( dma_buf != NULL ) { |
241 | munmap(dma_buf, dma_len); |
242 | dma_buf = NULL; |
243 | } |
244 | if ( audio_fd >= 0 ) { |
245 | close(audio_fd); |
246 | audio_fd = -1; |
247 | } |
248 | } |
249 | |
250 | static int DMA_ReopenAudio(_THIS, const char *audiodev, int format, int stereo, |
251 | SDL_AudioSpec *spec) |
252 | { |
253 | int frag_spec; |
254 | int value; |
255 | |
256 | /* Close and then reopen the audio device */ |
257 | close(audio_fd); |
258 | audio_fd = open(audiodev, O_RDWR, 0); |
259 | if ( audio_fd < 0 ) { |
260 | SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); |
261 | return(-1); |
262 | } |
263 | |
264 | /* Calculate the final parameters for this audio specification */ |
265 | SDL_CalculateAudioSpec(spec); |
266 | |
267 | /* Determine the power of two of the fragment size */ |
268 | for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec ); |
269 | if ( (0x01<<frag_spec) != spec->size ) { |
270 | SDL_SetError("Fragment size must be a power of two"); |
271 | return(-1); |
272 | } |
273 | |
274 | /* Set the audio buffering parameters */ |
275 | if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) { |
276 | SDL_SetError("Couldn't set audio fragment spec"); |
277 | return(-1); |
278 | } |
279 | |
280 | /* Set the audio format */ |
281 | value = format; |
282 | if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
283 | (value != format) ) { |
284 | SDL_SetError("Couldn't set audio format"); |
285 | return(-1); |
286 | } |
287 | |
288 | /* Set mono or stereo audio */ |
289 | value = (spec->channels > 1); |
290 | if ( (ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo) < 0) || |
291 | (value != stereo) ) { |
292 | SDL_SetError("Couldn't set audio channels"); |
293 | return(-1); |
294 | } |
295 | |
296 | /* Set the DSP frequency */ |
297 | value = spec->freq; |
298 | if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) { |
299 | SDL_SetError("Couldn't set audio frequency"); |
300 | return(-1); |
301 | } |
302 | spec->freq = value; |
303 | |
304 | /* We successfully re-opened the audio */ |
305 | return(0); |
306 | } |
307 | |
308 | static int DMA_OpenAudio(_THIS, SDL_AudioSpec *spec) |
309 | { |
310 | char audiodev[1024]; |
311 | int format; |
312 | int stereo; |
313 | int value; |
314 | Uint16 test_format; |
315 | struct audio_buf_info info; |
316 | |
317 | /* Reset the timer synchronization flag */ |
318 | frame_ticks = 0.0; |
319 | |
320 | /* Open the audio device */ |
321 | audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0); |
322 | if ( audio_fd < 0 ) { |
323 | SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); |
324 | return(-1); |
325 | } |
326 | dma_buf = NULL; |
327 | ioctl(audio_fd, SNDCTL_DSP_RESET, 0); |
328 | |
329 | /* Get a list of supported hardware formats */ |
330 | if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) { |
331 | SDL_SetError("Couldn't get audio format list"); |
332 | return(-1); |
333 | } |
334 | |
335 | /* Try for a closest match on audio format */ |
336 | format = 0; |
337 | for ( test_format = SDL_FirstAudioFormat(spec->format); |
338 | ! format && test_format; ) { |
339 | #ifdef DEBUG_AUDIO |
340 | fprintf(stderr, "Trying format 0x%4.4x\n", test_format); |
341 | #endif |
342 | switch ( test_format ) { |
343 | case AUDIO_U8: |
344 | if ( value & AFMT_U8 ) { |
345 | format = AFMT_U8; |
346 | } |
347 | break; |
348 | case AUDIO_S8: |
349 | if ( value & AFMT_S8 ) { |
350 | format = AFMT_S8; |
351 | } |
352 | break; |
353 | case AUDIO_S16LSB: |
354 | if ( value & AFMT_S16_LE ) { |
355 | format = AFMT_S16_LE; |
356 | } |
357 | break; |
358 | case AUDIO_S16MSB: |
359 | if ( value & AFMT_S16_BE ) { |
360 | format = AFMT_S16_BE; |
361 | } |
362 | break; |
363 | case AUDIO_U16LSB: |
364 | if ( value & AFMT_U16_LE ) { |
365 | format = AFMT_U16_LE; |
366 | } |
367 | break; |
368 | case AUDIO_U16MSB: |
369 | if ( value & AFMT_U16_BE ) { |
370 | format = AFMT_U16_BE; |
371 | } |
372 | break; |
373 | default: |
374 | format = 0; |
375 | break; |
376 | } |
377 | if ( ! format ) { |
378 | test_format = SDL_NextAudioFormat(); |
379 | } |
380 | } |
381 | if ( format == 0 ) { |
382 | SDL_SetError("Couldn't find any hardware audio formats"); |
383 | return(-1); |
384 | } |
385 | spec->format = test_format; |
386 | |
387 | /* Set the audio format */ |
388 | value = format; |
389 | if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
390 | (value != format) ) { |
391 | SDL_SetError("Couldn't set audio format"); |
392 | return(-1); |
393 | } |
394 | |
395 | /* Set mono or stereo audio (currently only two channels supported) */ |
396 | stereo = (spec->channels > 1); |
397 | ioctl(audio_fd, SNDCTL_DSP_STEREO, &stereo); |
398 | if ( stereo ) { |
399 | spec->channels = 2; |
400 | } else { |
401 | spec->channels = 1; |
402 | } |
403 | |
404 | /* Because some drivers don't allow setting the buffer size |
405 | after setting the format, we must re-open the audio device |
406 | once we know what format and channels are supported |
407 | */ |
408 | if ( DMA_ReopenAudio(this, audiodev, format, stereo, spec) < 0 ) { |
409 | /* Error is set by DMA_ReopenAudio() */ |
410 | return(-1); |
411 | } |
412 | |
413 | /* Memory map the audio buffer */ |
414 | if ( ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info) < 0 ) { |
415 | SDL_SetError("Couldn't get OSPACE parameters"); |
416 | return(-1); |
417 | } |
418 | spec->size = info.fragsize; |
419 | spec->samples = spec->size / ((spec->format & 0xFF) / 8); |
420 | spec->samples /= spec->channels; |
421 | num_buffers = info.fragstotal; |
422 | dma_len = num_buffers*spec->size; |
423 | dma_buf = (Uint8 *)mmap(NULL, dma_len, PROT_WRITE, MAP_SHARED, |
424 | audio_fd, 0); |
425 | if ( dma_buf == MAP_FAILED ) { |
426 | SDL_SetError("DMA memory map failed"); |
427 | dma_buf = NULL; |
428 | return(-1); |
429 | } |
430 | SDL_memset(dma_buf, spec->silence, dma_len); |
431 | |
432 | /* Check to see if we need to use select() workaround */ |
433 | { char *workaround; |
434 | workaround = SDL_getenv("SDL_DSP_NOSELECT"); |
435 | if ( workaround ) { |
436 | frame_ticks = (float)(spec->samples*1000)/spec->freq; |
437 | next_frame = SDL_GetTicks()+frame_ticks; |
438 | } |
439 | } |
440 | |
441 | /* Trigger audio playback */ |
442 | value = 0; |
443 | ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value); |
444 | value = PCM_ENABLE_OUTPUT; |
445 | if ( ioctl(audio_fd, SNDCTL_DSP_SETTRIGGER, &value) < 0 ) { |
446 | SDL_SetError("Couldn't trigger audio output"); |
447 | return(-1); |
448 | } |
449 | |
450 | /* Get the parent process id (we're the parent of the audio thread) */ |
451 | parent = getpid(); |
452 | |
453 | /* We're ready to rock and roll. :-) */ |
454 | return(0); |
455 | } |