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 | Modified in Oct 2004 by Hannu Savolainen |
23 | hannu@opensound.com |
24 | */ |
25 | #include "SDL_config.h" |
26 | |
27 | /* Allow access to a raw mixing buffer */ |
28 | |
29 | #include <stdio.h> /* For perror() */ |
30 | #include <string.h> /* For strerror() */ |
31 | #include <errno.h> |
32 | #include <unistd.h> |
33 | #include <fcntl.h> |
34 | #include <signal.h> |
35 | #include <sys/time.h> |
36 | #include <sys/ioctl.h> |
37 | #include <sys/stat.h> |
38 | |
39 | #if SDL_AUDIO_DRIVER_OSS_SOUNDCARD_H |
40 | /* This is installed on some systems */ |
41 | #include <soundcard.h> |
42 | #else |
43 | /* This is recommended by OSS */ |
44 | #include <sys/soundcard.h> |
45 | #endif |
46 | |
47 | #include "SDL_timer.h" |
48 | #include "SDL_audio.h" |
49 | #include "../SDL_audiomem.h" |
50 | #include "../SDL_audio_c.h" |
51 | #include "../SDL_audiodev_c.h" |
52 | #include "SDL_dspaudio.h" |
53 | |
54 | /* The tag name used by DSP audio */ |
55 | #define DSP_DRIVER_NAME "dsp" |
56 | |
57 | /* Open the audio device for playback, and don't block if busy */ |
58 | #define OPEN_FLAGS (O_WRONLY|O_NONBLOCK) |
59 | |
60 | /* Audio driver functions */ |
61 | static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec); |
62 | static void DSP_WaitAudio(_THIS); |
63 | static void DSP_PlayAudio(_THIS); |
64 | static Uint8 *DSP_GetAudioBuf(_THIS); |
65 | static void DSP_CloseAudio(_THIS); |
66 | |
67 | /* Audio driver bootstrap functions */ |
68 | |
69 | static int Audio_Available(void) |
70 | { |
71 | int fd; |
72 | int available; |
73 | |
74 | available = 0; |
75 | fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 0); |
76 | if ( fd >= 0 ) { |
77 | available = 1; |
78 | close(fd); |
79 | } |
80 | return(available); |
81 | } |
82 | |
83 | static void Audio_DeleteDevice(SDL_AudioDevice *device) |
84 | { |
85 | SDL_free(device->hidden); |
86 | SDL_free(device); |
87 | } |
88 | |
89 | static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
90 | { |
91 | SDL_AudioDevice *this; |
92 | |
93 | /* Initialize all variables that we clean on shutdown */ |
94 | this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); |
95 | if ( this ) { |
96 | SDL_memset(this, 0, (sizeof *this)); |
97 | this->hidden = (struct SDL_PrivateAudioData *) |
98 | SDL_malloc((sizeof *this->hidden)); |
99 | } |
100 | if ( (this == NULL) || (this->hidden == NULL) ) { |
101 | SDL_OutOfMemory(); |
102 | if ( this ) { |
103 | SDL_free(this); |
104 | } |
105 | return(0); |
106 | } |
107 | SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
108 | audio_fd = -1; |
109 | |
110 | /* Set the function pointers */ |
111 | this->OpenAudio = DSP_OpenAudio; |
112 | this->WaitAudio = DSP_WaitAudio; |
113 | this->PlayAudio = DSP_PlayAudio; |
114 | this->GetAudioBuf = DSP_GetAudioBuf; |
115 | this->CloseAudio = DSP_CloseAudio; |
116 | |
117 | this->free = Audio_DeleteDevice; |
118 | |
119 | return this; |
120 | } |
121 | |
122 | AudioBootStrap DSP_bootstrap = { |
123 | DSP_DRIVER_NAME, "OSS /dev/dsp standard audio", |
124 | Audio_Available, Audio_CreateDevice |
125 | }; |
126 | |
127 | /* This function waits until it is possible to write a full sound buffer */ |
128 | static void DSP_WaitAudio(_THIS) |
129 | { |
130 | /* Not needed at all since OSS handles waiting automagically */ |
131 | } |
132 | |
133 | static void DSP_PlayAudio(_THIS) |
134 | { |
135 | if (write(audio_fd, mixbuf, mixlen)==-1) |
136 | { |
137 | perror("Audio write"); |
138 | this->enabled = 0; |
139 | } |
140 | |
141 | #ifdef DEBUG_AUDIO |
142 | fprintf(stderr, "Wrote %d bytes of audio data\n", mixlen); |
143 | #endif |
144 | } |
145 | |
146 | static Uint8 *DSP_GetAudioBuf(_THIS) |
147 | { |
148 | return(mixbuf); |
149 | } |
150 | |
151 | static void DSP_CloseAudio(_THIS) |
152 | { |
153 | if ( mixbuf != NULL ) { |
154 | SDL_FreeAudioMem(mixbuf); |
155 | mixbuf = NULL; |
156 | } |
157 | if ( audio_fd >= 0 ) { |
158 | close(audio_fd); |
159 | audio_fd = -1; |
160 | } |
161 | } |
162 | |
163 | static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec) |
164 | { |
165 | char audiodev[1024]; |
166 | int format; |
167 | int value; |
168 | int frag_spec; |
169 | Uint16 test_format; |
170 | |
171 | /* Make sure fragment size stays a power of 2, or OSS fails. */ |
172 | /* I don't know which of these are actually legal values, though... */ |
173 | if (spec->channels > 8) |
174 | spec->channels = 8; |
175 | else if (spec->channels > 4) |
176 | spec->channels = 4; |
177 | else if (spec->channels > 2) |
178 | spec->channels = 2; |
179 | |
180 | /* Open the audio device */ |
181 | audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 0); |
182 | if ( audio_fd < 0 ) { |
183 | SDL_SetError("Couldn't open %s: %s", audiodev, strerror(errno)); |
184 | return(-1); |
185 | } |
186 | mixbuf = NULL; |
187 | |
188 | /* Make the file descriptor use blocking writes with fcntl() */ |
189 | { long flags; |
190 | flags = fcntl(audio_fd, F_GETFL); |
191 | flags &= ~O_NONBLOCK; |
192 | if ( fcntl(audio_fd, F_SETFL, flags) < 0 ) { |
193 | SDL_SetError("Couldn't set audio blocking mode"); |
194 | DSP_CloseAudio(this); |
195 | return(-1); |
196 | } |
197 | } |
198 | |
199 | /* Get a list of supported hardware formats */ |
200 | if ( ioctl(audio_fd, SNDCTL_DSP_GETFMTS, &value) < 0 ) { |
201 | perror("SNDCTL_DSP_GETFMTS"); |
202 | SDL_SetError("Couldn't get audio format list"); |
203 | DSP_CloseAudio(this); |
204 | return(-1); |
205 | } |
206 | |
207 | /* Try for a closest match on audio format */ |
208 | format = 0; |
209 | for ( test_format = SDL_FirstAudioFormat(spec->format); |
210 | ! format && test_format; ) { |
211 | #ifdef DEBUG_AUDIO |
212 | fprintf(stderr, "Trying format 0x%4.4x\n", test_format); |
213 | #endif |
214 | switch ( test_format ) { |
215 | case AUDIO_U8: |
216 | if ( value & AFMT_U8 ) { |
217 | format = AFMT_U8; |
218 | } |
219 | break; |
220 | case AUDIO_S16LSB: |
221 | if ( value & AFMT_S16_LE ) { |
222 | format = AFMT_S16_LE; |
223 | } |
224 | break; |
225 | case AUDIO_S16MSB: |
226 | if ( value & AFMT_S16_BE ) { |
227 | format = AFMT_S16_BE; |
228 | } |
229 | break; |
230 | #if 0 |
231 | /* |
232 | * These formats are not used by any real life systems so they are not |
233 | * needed here. |
234 | */ |
235 | case AUDIO_S8: |
236 | if ( value & AFMT_S8 ) { |
237 | format = AFMT_S8; |
238 | } |
239 | break; |
240 | case AUDIO_U16LSB: |
241 | if ( value & AFMT_U16_LE ) { |
242 | format = AFMT_U16_LE; |
243 | } |
244 | break; |
245 | case AUDIO_U16MSB: |
246 | if ( value & AFMT_U16_BE ) { |
247 | format = AFMT_U16_BE; |
248 | } |
249 | break; |
250 | #endif |
251 | default: |
252 | format = 0; |
253 | break; |
254 | } |
255 | if ( ! format ) { |
256 | test_format = SDL_NextAudioFormat(); |
257 | } |
258 | } |
259 | if ( format == 0 ) { |
260 | SDL_SetError("Couldn't find any hardware audio formats"); |
261 | DSP_CloseAudio(this); |
262 | return(-1); |
263 | } |
264 | spec->format = test_format; |
265 | |
266 | /* Set the audio format */ |
267 | value = format; |
268 | if ( (ioctl(audio_fd, SNDCTL_DSP_SETFMT, &value) < 0) || |
269 | (value != format) ) { |
270 | perror("SNDCTL_DSP_SETFMT"); |
271 | SDL_SetError("Couldn't set audio format"); |
272 | DSP_CloseAudio(this); |
273 | return(-1); |
274 | } |
275 | |
276 | /* Set the number of channels of output */ |
277 | value = spec->channels; |
278 | if ( ioctl(audio_fd, SNDCTL_DSP_CHANNELS, &value) < 0 ) { |
279 | perror("SNDCTL_DSP_CHANNELS"); |
280 | SDL_SetError("Cannot set the number of channels"); |
281 | DSP_CloseAudio(this); |
282 | return(-1); |
283 | } |
284 | spec->channels = value; |
285 | |
286 | /* Set the DSP frequency */ |
287 | value = spec->freq; |
288 | if ( ioctl(audio_fd, SNDCTL_DSP_SPEED, &value) < 0 ) { |
289 | perror("SNDCTL_DSP_SPEED"); |
290 | SDL_SetError("Couldn't set audio frequency"); |
291 | DSP_CloseAudio(this); |
292 | return(-1); |
293 | } |
294 | spec->freq = value; |
295 | |
296 | /* Calculate the final parameters for this audio specification */ |
297 | SDL_CalculateAudioSpec(spec); |
298 | |
299 | /* Determine the power of two of the fragment size */ |
300 | for ( frag_spec = 0; (0x01U<<frag_spec) < spec->size; ++frag_spec ); |
301 | if ( (0x01U<<frag_spec) != spec->size ) { |
302 | SDL_SetError("Fragment size must be a power of two"); |
303 | DSP_CloseAudio(this); |
304 | return(-1); |
305 | } |
306 | frag_spec |= 0x00020000; /* two fragments, for low latency */ |
307 | |
308 | /* Set the audio buffering parameters */ |
309 | #ifdef DEBUG_AUDIO |
310 | fprintf(stderr, "Requesting %d fragments of size %d\n", |
311 | (frag_spec >> 16), 1<<(frag_spec&0xFFFF)); |
312 | #endif |
313 | if ( ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &frag_spec) < 0 ) { |
314 | perror("SNDCTL_DSP_SETFRAGMENT"); |
315 | } |
316 | #ifdef DEBUG_AUDIO |
317 | { audio_buf_info info; |
318 | ioctl(audio_fd, SNDCTL_DSP_GETOSPACE, &info); |
319 | fprintf(stderr, "fragments = %d\n", info.fragments); |
320 | fprintf(stderr, "fragstotal = %d\n", info.fragstotal); |
321 | fprintf(stderr, "fragsize = %d\n", info.fragsize); |
322 | fprintf(stderr, "bytes = %d\n", info.bytes); |
323 | } |
324 | #endif |
325 | |
326 | /* Allocate mixing buffer */ |
327 | mixlen = spec->size; |
328 | mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); |
329 | if ( mixbuf == NULL ) { |
330 | DSP_CloseAudio(this); |
331 | return(-1); |
332 | } |
333 | SDL_memset(mixbuf, spec->silence, spec->size); |
334 | |
335 | /* Get the parent process id (we're the parent of the audio thread) */ |
336 | parent = getpid(); |
337 | |
338 | /* We're ready to rock and roll. :-) */ |
339 | return(0); |
340 | } |