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 an ESD network stream mixing buffer */ |
25 | |
26 | #include <sys/types.h> |
27 | #include <unistd.h> |
28 | #include <signal.h> |
29 | #include <errno.h> |
30 | #include <esd.h> |
31 | |
32 | #include "SDL_timer.h" |
33 | #include "SDL_audio.h" |
34 | #include "../SDL_audiomem.h" |
35 | #include "../SDL_audio_c.h" |
36 | #include "../SDL_audiodev_c.h" |
37 | #include "SDL_esdaudio.h" |
38 | |
39 | #ifdef SDL_AUDIO_DRIVER_ESD_DYNAMIC |
40 | #include "SDL_name.h" |
41 | #include "SDL_loadso.h" |
42 | #else |
43 | #define SDL_NAME(X) X |
44 | #endif |
45 | |
46 | /* The tag name used by ESD audio */ |
47 | #define ESD_DRIVER_NAME "esd" |
48 | |
49 | /* Audio driver functions */ |
50 | static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec); |
51 | static void ESD_WaitAudio(_THIS); |
52 | static void ESD_PlayAudio(_THIS); |
53 | static Uint8 *ESD_GetAudioBuf(_THIS); |
54 | static void ESD_CloseAudio(_THIS); |
55 | |
56 | #ifdef SDL_AUDIO_DRIVER_ESD_DYNAMIC |
57 | |
58 | static const char *esd_library = SDL_AUDIO_DRIVER_ESD_DYNAMIC; |
59 | static void *esd_handle = NULL; |
60 | static int esd_loaded = 0; |
61 | |
62 | static int (*SDL_NAME(esd_open_sound))( const char *host ); |
63 | static int (*SDL_NAME(esd_close))( int esd ); |
64 | static int (*SDL_NAME(esd_play_stream))( esd_format_t format, int rate, |
65 | const char *host, const char *name ); |
66 | static struct { |
67 | const char *name; |
68 | void **func; |
69 | } esd_functions[] = { |
70 | { "esd_open_sound", (void **)&SDL_NAME(esd_open_sound) }, |
71 | { "esd_close", (void **)&SDL_NAME(esd_close) }, |
72 | { "esd_play_stream", (void **)&SDL_NAME(esd_play_stream) }, |
73 | }; |
74 | |
75 | static void UnloadESDLibrary() |
76 | { |
77 | if ( esd_loaded ) { |
78 | SDL_UnloadObject(esd_handle); |
79 | esd_handle = NULL; |
80 | esd_loaded = 0; |
81 | } |
82 | } |
83 | |
84 | static int LoadESDLibrary(void) |
85 | { |
86 | int i, retval = -1; |
87 | |
88 | esd_handle = SDL_LoadObject(esd_library); |
89 | if ( esd_handle ) { |
90 | esd_loaded = 1; |
91 | retval = 0; |
92 | for ( i=0; i<SDL_arraysize(esd_functions); ++i ) { |
93 | *esd_functions[i].func = SDL_LoadFunction(esd_handle, esd_functions[i].name); |
94 | if ( !*esd_functions[i].func ) { |
95 | retval = -1; |
96 | UnloadESDLibrary(); |
97 | break; |
98 | } |
99 | } |
100 | } |
101 | return retval; |
102 | } |
103 | |
104 | #else |
105 | |
106 | static void UnloadESDLibrary() |
107 | { |
108 | return; |
109 | } |
110 | |
111 | static int LoadESDLibrary(void) |
112 | { |
113 | return 0; |
114 | } |
115 | |
116 | #endif /* SDL_AUDIO_DRIVER_ESD_DYNAMIC */ |
117 | |
118 | /* Audio driver bootstrap functions */ |
119 | |
120 | static int Audio_Available(void) |
121 | { |
122 | int connection; |
123 | int available; |
124 | |
125 | available = 0; |
126 | if ( LoadESDLibrary() < 0 ) { |
127 | return available; |
128 | } |
129 | connection = SDL_NAME(esd_open_sound)(NULL); |
130 | if ( connection >= 0 ) { |
131 | available = 1; |
132 | SDL_NAME(esd_close)(connection); |
133 | } |
134 | UnloadESDLibrary(); |
135 | return(available); |
136 | } |
137 | |
138 | static void Audio_DeleteDevice(SDL_AudioDevice *device) |
139 | { |
140 | SDL_free(device->hidden); |
141 | SDL_free(device); |
142 | UnloadESDLibrary(); |
143 | } |
144 | |
145 | static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
146 | { |
147 | SDL_AudioDevice *this; |
148 | |
149 | /* Initialize all variables that we clean on shutdown */ |
150 | LoadESDLibrary(); |
151 | this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); |
152 | if ( this ) { |
153 | SDL_memset(this, 0, (sizeof *this)); |
154 | this->hidden = (struct SDL_PrivateAudioData *) |
155 | SDL_malloc((sizeof *this->hidden)); |
156 | } |
157 | if ( (this == NULL) || (this->hidden == NULL) ) { |
158 | SDL_OutOfMemory(); |
159 | if ( this ) { |
160 | SDL_free(this); |
161 | } |
162 | return(0); |
163 | } |
164 | SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
165 | audio_fd = -1; |
166 | |
167 | /* Set the function pointers */ |
168 | this->OpenAudio = ESD_OpenAudio; |
169 | this->WaitAudio = ESD_WaitAudio; |
170 | this->PlayAudio = ESD_PlayAudio; |
171 | this->GetAudioBuf = ESD_GetAudioBuf; |
172 | this->CloseAudio = ESD_CloseAudio; |
173 | |
174 | this->free = Audio_DeleteDevice; |
175 | |
176 | return this; |
177 | } |
178 | |
179 | AudioBootStrap ESD_bootstrap = { |
180 | ESD_DRIVER_NAME, "Enlightened Sound Daemon", |
181 | Audio_Available, Audio_CreateDevice |
182 | }; |
183 | |
184 | /* This function waits until it is possible to write a full sound buffer */ |
185 | static void ESD_WaitAudio(_THIS) |
186 | { |
187 | Sint32 ticks; |
188 | |
189 | /* Check to see if the thread-parent process is still alive */ |
190 | { static int cnt = 0; |
191 | /* Note that this only works with thread implementations |
192 | that use a different process id for each thread. |
193 | */ |
194 | if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ |
195 | if ( kill(parent, 0) < 0 ) { |
196 | this->enabled = 0; |
197 | } |
198 | } |
199 | } |
200 | |
201 | /* Use timer for general audio synchronization */ |
202 | ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; |
203 | if ( ticks > 0 ) { |
204 | SDL_Delay(ticks); |
205 | } |
206 | } |
207 | |
208 | static void ESD_PlayAudio(_THIS) |
209 | { |
210 | int written; |
211 | |
212 | /* Write the audio data, checking for EAGAIN on broken audio drivers */ |
213 | do { |
214 | written = write(audio_fd, mixbuf, mixlen); |
215 | if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) { |
216 | SDL_Delay(1); /* Let a little CPU time go by */ |
217 | } |
218 | } while ( (written < 0) && |
219 | ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) ); |
220 | |
221 | /* Set the next write frame */ |
222 | next_frame += frame_ticks; |
223 | |
224 | /* If we couldn't write, assume fatal error for now */ |
225 | if ( written < 0 ) { |
226 | this->enabled = 0; |
227 | } |
228 | } |
229 | |
230 | static Uint8 *ESD_GetAudioBuf(_THIS) |
231 | { |
232 | return(mixbuf); |
233 | } |
234 | |
235 | static void ESD_CloseAudio(_THIS) |
236 | { |
237 | if ( mixbuf != NULL ) { |
238 | SDL_FreeAudioMem(mixbuf); |
239 | mixbuf = NULL; |
240 | } |
241 | if ( audio_fd >= 0 ) { |
242 | SDL_NAME(esd_close)(audio_fd); |
243 | audio_fd = -1; |
244 | } |
245 | } |
246 | |
247 | /* Try to get the name of the program */ |
248 | static char *get_progname(void) |
249 | { |
250 | char *progname = NULL; |
251 | #ifdef __LINUX__ |
252 | FILE *fp; |
253 | static char temp[BUFSIZ]; |
254 | |
255 | SDL_snprintf(temp, SDL_arraysize(temp), "/proc/%d/cmdline", getpid()); |
256 | fp = fopen(temp, "r"); |
257 | if ( fp != NULL ) { |
258 | if ( fgets(temp, sizeof(temp)-1, fp) ) { |
259 | progname = SDL_strrchr(temp, '/'); |
260 | if ( progname == NULL ) { |
261 | progname = temp; |
262 | } else { |
263 | progname = progname+1; |
264 | } |
265 | } |
266 | fclose(fp); |
267 | } |
268 | #endif |
269 | return(progname); |
270 | } |
271 | |
272 | static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec) |
273 | { |
274 | esd_format_t format; |
275 | |
276 | /* Convert audio spec to the ESD audio format */ |
277 | format = (ESD_STREAM | ESD_PLAY); |
278 | switch ( spec->format & 0xFF ) { |
279 | case 8: |
280 | format |= ESD_BITS8; |
281 | break; |
282 | case 16: |
283 | format |= ESD_BITS16; |
284 | break; |
285 | default: |
286 | SDL_SetError("Unsupported ESD audio format"); |
287 | return(-1); |
288 | } |
289 | if ( spec->channels == 1 ) { |
290 | format |= ESD_MONO; |
291 | } else { |
292 | format |= ESD_STEREO; |
293 | } |
294 | #if 0 |
295 | spec->samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */ |
296 | #endif |
297 | |
298 | /* Open a connection to the ESD audio server */ |
299 | audio_fd = SDL_NAME(esd_play_stream)(format, spec->freq, NULL, get_progname()); |
300 | if ( audio_fd < 0 ) { |
301 | SDL_SetError("Couldn't open ESD connection"); |
302 | return(-1); |
303 | } |
304 | |
305 | /* Calculate the final parameters for this audio specification */ |
306 | SDL_CalculateAudioSpec(spec); |
307 | frame_ticks = (float)(spec->samples*1000)/spec->freq; |
308 | next_frame = SDL_GetTicks()+frame_ticks; |
309 | |
310 | /* Allocate mixing buffer */ |
311 | mixlen = spec->size; |
312 | mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); |
313 | if ( mixbuf == NULL ) { |
314 | return(-1); |
315 | } |
316 | SDL_memset(mixbuf, spec->silence, spec->size); |
317 | |
318 | /* Get the parent process id (we're the parent of the audio thread) */ |
319 | parent = getpid(); |
320 | |
321 | /* We're ready to rock and roll. :-) */ |
322 | return(0); |
323 | } |