xref: /openbmc/qemu/audio/sdlaudio.c (revision 19f70347)
1 /*
2  * QEMU SDL audio driver
3  *
4  * Copyright (c) 2004-2005 Vassili Karpov (malc)
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include <SDL.h>
27 #include <SDL_thread.h>
28 #include "qemu/module.h"
29 #include "audio.h"
30 
31 #ifndef _WIN32
32 #ifdef __sun__
33 #define _POSIX_PTHREAD_SEMANTICS 1
34 #elif defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
35 #include <pthread.h>
36 #endif
37 #endif
38 
39 #define AUDIO_CAP "sdl"
40 #include "audio_int.h"
41 
42 typedef struct SDLVoiceOut {
43     HWVoiceOut hw;
44 } SDLVoiceOut;
45 
46 static struct SDLAudioState {
47     int exit;
48     int initialized;
49     bool driver_created;
50     Audiodev *dev;
51 } glob_sdl;
52 typedef struct SDLAudioState SDLAudioState;
53 
54 static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char *fmt, ...)
55 {
56     va_list ap;
57 
58     va_start (ap, fmt);
59     AUD_vlog (AUDIO_CAP, fmt, ap);
60     va_end (ap);
61 
62     AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
63 }
64 
65 static int aud_to_sdlfmt (AudioFormat fmt)
66 {
67     switch (fmt) {
68     case AUDIO_FORMAT_S8:
69         return AUDIO_S8;
70 
71     case AUDIO_FORMAT_U8:
72         return AUDIO_U8;
73 
74     case AUDIO_FORMAT_S16:
75         return AUDIO_S16LSB;
76 
77     case AUDIO_FORMAT_U16:
78         return AUDIO_U16LSB;
79 
80     case AUDIO_FORMAT_S32:
81         return AUDIO_S32LSB;
82 
83     /* no unsigned 32-bit support in SDL */
84 
85     case AUDIO_FORMAT_F32:
86         return AUDIO_F32LSB;
87 
88     default:
89         dolog ("Internal logic error: Bad audio format %d\n", fmt);
90 #ifdef DEBUG_AUDIO
91         abort ();
92 #endif
93         return AUDIO_U8;
94     }
95 }
96 
97 static int sdl_to_audfmt(int sdlfmt, AudioFormat *fmt, int *endianness)
98 {
99     switch (sdlfmt) {
100     case AUDIO_S8:
101         *endianness = 0;
102         *fmt = AUDIO_FORMAT_S8;
103         break;
104 
105     case AUDIO_U8:
106         *endianness = 0;
107         *fmt = AUDIO_FORMAT_U8;
108         break;
109 
110     case AUDIO_S16LSB:
111         *endianness = 0;
112         *fmt = AUDIO_FORMAT_S16;
113         break;
114 
115     case AUDIO_U16LSB:
116         *endianness = 0;
117         *fmt = AUDIO_FORMAT_U16;
118         break;
119 
120     case AUDIO_S16MSB:
121         *endianness = 1;
122         *fmt = AUDIO_FORMAT_S16;
123         break;
124 
125     case AUDIO_U16MSB:
126         *endianness = 1;
127         *fmt = AUDIO_FORMAT_U16;
128         break;
129 
130     case AUDIO_S32LSB:
131         *endianness = 0;
132         *fmt = AUDIO_FORMAT_S32;
133         break;
134 
135     case AUDIO_S32MSB:
136         *endianness = 1;
137         *fmt = AUDIO_FORMAT_S32;
138         break;
139 
140     case AUDIO_F32LSB:
141         *endianness = 0;
142         *fmt = AUDIO_FORMAT_F32;
143         break;
144 
145     case AUDIO_F32MSB:
146         *endianness = 1;
147         *fmt = AUDIO_FORMAT_F32;
148         break;
149 
150     default:
151         dolog ("Unrecognized SDL audio format %d\n", sdlfmt);
152         return -1;
153     }
154 
155     return 0;
156 }
157 
158 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
159 {
160     int status;
161 #ifndef _WIN32
162     int err;
163     sigset_t new, old;
164 
165     /* Make sure potential threads created by SDL don't hog signals.  */
166     err = sigfillset (&new);
167     if (err) {
168         dolog ("sdl_open: sigfillset failed: %s\n", strerror (errno));
169         return -1;
170     }
171     err = pthread_sigmask (SIG_BLOCK, &new, &old);
172     if (err) {
173         dolog ("sdl_open: pthread_sigmask failed: %s\n", strerror (err));
174         return -1;
175     }
176 #endif
177 
178     status = SDL_OpenAudio (req, obt);
179     if (status) {
180         sdl_logerr ("SDL_OpenAudio failed\n");
181     }
182 
183 #ifndef _WIN32
184     err = pthread_sigmask (SIG_SETMASK, &old, NULL);
185     if (err) {
186         dolog ("sdl_open: pthread_sigmask (restore) failed: %s\n",
187                strerror (errno));
188         /* We have failed to restore original signal mask, all bets are off,
189            so exit the process */
190         exit (EXIT_FAILURE);
191     }
192 #endif
193     return status;
194 }
195 
196 static void sdl_close (SDLAudioState *s)
197 {
198     if (s->initialized) {
199         SDL_LockAudio();
200         s->exit = 1;
201         SDL_UnlockAudio();
202         SDL_PauseAudio (1);
203         SDL_CloseAudio ();
204         s->initialized = 0;
205     }
206 }
207 
208 static void sdl_callback (void *opaque, Uint8 *buf, int len)
209 {
210     SDLVoiceOut *sdl = opaque;
211     SDLAudioState *s = &glob_sdl;
212     HWVoiceOut *hw = &sdl->hw;
213 
214     if (s->exit) {
215         return;
216     }
217 
218     /* dolog ("in callback samples=%zu live=%zu\n", samples, sdl->live); */
219 
220     while (hw->pending_emul && len) {
221         size_t write_len;
222         ssize_t start = ((ssize_t) hw->pos_emul) - hw->pending_emul;
223         if (start < 0) {
224             start += hw->size_emul;
225         }
226         assert(start >= 0 && start < hw->size_emul);
227 
228         write_len = MIN(MIN(hw->pending_emul, len),
229                         hw->size_emul - start);
230 
231         memcpy(buf, hw->buf_emul + start, write_len);
232         hw->pending_emul -= write_len;
233         len -= write_len;
234         buf += write_len;
235     }
236 
237     /* clear remaining buffer that we couldn't fill with data */
238     if (len) {
239         memset(buf, 0, len);
240     }
241 }
242 
243 #define SDL_WRAPPER_FUNC(name, ret_type, args_decl, args, fail, unlock) \
244     static ret_type glue(sdl_, name)args_decl                           \
245     {                                                                   \
246         ret_type ret;                                                   \
247                                                                         \
248         SDL_LockAudio();                                                \
249                                                                         \
250         ret = glue(audio_generic_, name)args;                           \
251                                                                         \
252         SDL_UnlockAudio();                                              \
253         return ret;                                                     \
254     }
255 
256 SDL_WRAPPER_FUNC(get_buffer_out, void *, (HWVoiceOut *hw, size_t *size),
257                  (hw, size), *size = 0, sdl_unlock)
258 SDL_WRAPPER_FUNC(put_buffer_out, size_t,
259                  (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size),
260                  /*nothing*/, sdl_unlock_and_post)
261 SDL_WRAPPER_FUNC(write, size_t,
262                  (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size),
263                  /*nothing*/, sdl_unlock_and_post)
264 
265 #undef SDL_WRAPPER_FUNC
266 
267 static void sdl_fini_out (HWVoiceOut *hw)
268 {
269     (void) hw;
270 
271     sdl_close (&glob_sdl);
272 }
273 
274 static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as,
275                         void *drv_opaque)
276 {
277     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
278     SDLAudioState *s = &glob_sdl;
279     SDL_AudioSpec req, obt;
280     int endianness;
281     int err;
282     AudioFormat effective_fmt;
283     struct audsettings obt_as;
284 
285     req.freq = as->freq;
286     req.format = aud_to_sdlfmt (as->fmt);
287     req.channels = as->nchannels;
288     req.samples = audio_buffer_samples(s->dev->u.sdl.out, as, 11610);
289     req.callback = sdl_callback;
290     req.userdata = sdl;
291 
292     if (sdl_open (&req, &obt)) {
293         return -1;
294     }
295 
296     err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
297     if (err) {
298         sdl_close (s);
299         return -1;
300     }
301 
302     obt_as.freq = obt.freq;
303     obt_as.nchannels = obt.channels;
304     obt_as.fmt = effective_fmt;
305     obt_as.endianness = endianness;
306 
307     audio_pcm_init_info (&hw->info, &obt_as);
308     hw->samples = obt.samples;
309 
310     s->initialized = 1;
311     s->exit = 0;
312     SDL_PauseAudio (0);
313     return 0;
314 }
315 
316 static void sdl_enable_out(HWVoiceOut *hw, bool enable)
317 {
318     SDL_PauseAudio(!enable);
319 }
320 
321 static void *sdl_audio_init(Audiodev *dev)
322 {
323     SDLAudioState *s = &glob_sdl;
324     if (s->driver_created) {
325         sdl_logerr("Can't create multiple sdl backends\n");
326         return NULL;
327     }
328 
329     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
330         sdl_logerr ("SDL failed to initialize audio subsystem\n");
331         return NULL;
332     }
333 
334     s->driver_created = true;
335     s->dev = dev;
336     return s;
337 }
338 
339 static void sdl_audio_fini (void *opaque)
340 {
341     SDLAudioState *s = opaque;
342     sdl_close (s);
343     SDL_QuitSubSystem (SDL_INIT_AUDIO);
344     s->driver_created = false;
345     s->dev = NULL;
346 }
347 
348 static struct audio_pcm_ops sdl_pcm_ops = {
349     .init_out = sdl_init_out,
350     .fini_out = sdl_fini_out,
351   /* wrapper for audio_generic_write */
352     .write    = sdl_write,
353   /* wrapper for audio_generic_get_buffer_out */
354     .get_buffer_out = sdl_get_buffer_out,
355   /* wrapper for audio_generic_put_buffer_out */
356     .put_buffer_out = sdl_put_buffer_out,
357     .enable_out = sdl_enable_out,
358 };
359 
360 static struct audio_driver sdl_audio_driver = {
361     .name           = "sdl",
362     .descr          = "SDL http://www.libsdl.org",
363     .init           = sdl_audio_init,
364     .fini           = sdl_audio_fini,
365     .pcm_ops        = &sdl_pcm_ops,
366     .can_be_default = 1,
367     .max_voices_out = 1,
368     .max_voices_in  = 0,
369     .voice_size_out = sizeof (SDLVoiceOut),
370     .voice_size_in  = 0
371 };
372 
373 static void register_audio_sdl(void)
374 {
375     audio_driver_register(&sdl_audio_driver);
376 }
377 type_init(register_audio_sdl);
378