xref: /openbmc/qemu/audio/sdlaudio.c (revision 5a0926c2)
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("callback: len=%d avail=%zu\n", len, hw->pending_emul); */
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)      \
244     static ret_type glue(sdl_, name)args_decl                  \
245     {                                                          \
246         ret_type ret;                                          \
247                                                                \
248         SDL_LockAudio();                                       \
249         ret = glue(audio_generic_, name)args;                  \
250         SDL_UnlockAudio();                                     \
251                                                                \
252         return ret;                                            \
253     }
254 
255 SDL_WRAPPER_FUNC(get_buffer_out, void *, (HWVoiceOut *hw, size_t *size),
256                  (hw, size))
257 SDL_WRAPPER_FUNC(put_buffer_out, size_t,
258                  (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size))
259 SDL_WRAPPER_FUNC(write, size_t,
260                  (HWVoiceOut *hw, void *buf, size_t size), (hw, buf, size))
261 #undef SDL_WRAPPER_FUNC
262 
263 static void sdl_fini_out (HWVoiceOut *hw)
264 {
265     (void) hw;
266 
267     sdl_close (&glob_sdl);
268 }
269 
270 static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as,
271                         void *drv_opaque)
272 {
273     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
274     SDLAudioState *s = &glob_sdl;
275     SDL_AudioSpec req, obt;
276     int endianness;
277     int err;
278     AudioFormat effective_fmt;
279     AudiodevSdlPerDirectionOptions *spdo = s->dev->u.sdl.out;
280     struct audsettings obt_as;
281 
282     req.freq = as->freq;
283     req.format = aud_to_sdlfmt (as->fmt);
284     req.channels = as->nchannels;
285     /*
286      * This is wrong. SDL samples are QEMU frames. The buffer size will be
287      * the requested buffer size multiplied by the number of channels.
288      */
289     req.samples = audio_buffer_samples(
290         qapi_AudiodevSdlPerDirectionOptions_base(spdo), as, 11610);
291     req.callback = sdl_callback;
292     req.userdata = sdl;
293 
294     if (sdl_open (&req, &obt)) {
295         return -1;
296     }
297 
298     err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
299     if (err) {
300         sdl_close (s);
301         return -1;
302     }
303 
304     obt_as.freq = obt.freq;
305     obt_as.nchannels = obt.channels;
306     obt_as.fmt = effective_fmt;
307     obt_as.endianness = endianness;
308 
309     audio_pcm_init_info (&hw->info, &obt_as);
310     hw->samples = (spdo->has_buffer_count ? spdo->buffer_count : 4) *
311         obt.samples;
312 
313     s->initialized = 1;
314     s->exit = 0;
315     SDL_PauseAudio (0);
316     return 0;
317 }
318 
319 static void sdl_enable_out(HWVoiceOut *hw, bool enable)
320 {
321     SDL_PauseAudio(!enable);
322 }
323 
324 static void *sdl_audio_init(Audiodev *dev)
325 {
326     SDLAudioState *s = &glob_sdl;
327     if (s->driver_created) {
328         sdl_logerr("Can't create multiple sdl backends\n");
329         return NULL;
330     }
331 
332     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
333         sdl_logerr ("SDL failed to initialize audio subsystem\n");
334         return NULL;
335     }
336 
337     s->driver_created = true;
338     s->dev = dev;
339     return s;
340 }
341 
342 static void sdl_audio_fini (void *opaque)
343 {
344     SDLAudioState *s = opaque;
345     sdl_close (s);
346     SDL_QuitSubSystem (SDL_INIT_AUDIO);
347     s->driver_created = false;
348     s->dev = NULL;
349 }
350 
351 static struct audio_pcm_ops sdl_pcm_ops = {
352     .init_out = sdl_init_out,
353     .fini_out = sdl_fini_out,
354   /* wrapper for audio_generic_write */
355     .write    = sdl_write,
356   /* wrapper for audio_generic_get_buffer_out */
357     .get_buffer_out = sdl_get_buffer_out,
358   /* wrapper for audio_generic_put_buffer_out */
359     .put_buffer_out = sdl_put_buffer_out,
360     .enable_out = sdl_enable_out,
361 };
362 
363 static struct audio_driver sdl_audio_driver = {
364     .name           = "sdl",
365     .descr          = "SDL http://www.libsdl.org",
366     .init           = sdl_audio_init,
367     .fini           = sdl_audio_fini,
368     .pcm_ops        = &sdl_pcm_ops,
369     .can_be_default = 1,
370     .max_voices_out = 1,
371     .max_voices_in  = 0,
372     .voice_size_out = sizeof (SDLVoiceOut),
373     .voice_size_in  = 0
374 };
375 
376 static void register_audio_sdl(void)
377 {
378     audio_driver_register(&sdl_audio_driver);
379 }
380 type_init(register_audio_sdl);
381