audio/sdlaudio.c

   1 /*
   2  * QEMU SDL audio output driver
   3  *
   4  * Copyright (c) 2004 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 #include <SDL/SDL.h>
  25 #include <SDL/SDL_thread.h>
  26 #include "vl.h"
  27
  28 #define AUDIO_CAP "sdl"
  29 #include "audio/audio.h"
  30 #include "audio/sdlaudio.h"
  31
  32 #define QC_SDL_SAMPLES "QEMU_SDL_SAMPLES"
  33
  34 #define errstr() SDL_GetError ()
  35
  36 static struct {
  37     int nb_samples;
  38 } conf = {
  39     1024
  40 };
  41
  42 struct SDLAudioState {
  43     int exit;
  44     SDL_mutex *mutex;
  45     SDL_sem *sem;
  46     int initialized;
  47 } glob_sdl;
  48 typedef struct SDLAudioState SDLAudioState;
  49
  50 static void sdl_hw_run (HWVoice *hw)
  51 {
  52     (void) hw;
  53 }
  54
  55 static int sdl_lock (SDLAudioState *s)
  56 {
  57     if (SDL_LockMutex (s->mutex)) {
  58         dolog ("SDL_LockMutex failed\nReason: %s\n", errstr ());
  59         return -1;
  60     }
  61     return 0;
  62 }
  63
  64 static int sdl_unlock (SDLAudioState *s)
  65 {
  66     if (SDL_UnlockMutex (s->mutex)) {
  67         dolog ("SDL_UnlockMutex failed\nReason: %s\n", errstr ());
  68         return -1;
  69     }
  70     return 0;
  71 }
  72
  73 static int sdl_post (SDLAudioState *s)
  74 {
  75     if (SDL_SemPost (s->sem)) {
  76         dolog ("SDL_SemPost failed\nReason: %s\n", errstr ());
  77         return -1;
  78     }
  79     return 0;
  80 }
  81
  82 static int sdl_wait (SDLAudioState *s)
  83 {
  84     if (SDL_SemWait (s->sem)) {
  85         dolog ("SDL_SemWait failed\nReason: %s\n", errstr ());
  86         return -1;
  87     }
  88     return 0;
  89 }
  90
  91 static int sdl_unlock_and_post (SDLAudioState *s)
  92 {
  93     if (sdl_unlock (s))
  94         return -1;
  95
  96     return sdl_post (s);
  97 }
  98
  99 static int sdl_hw_write (SWVoice *sw, void *buf, int len)
 100 {
 101     int ret;
 102     SDLAudioState *s = &glob_sdl;
 103     sdl_lock (s);
 104     ret = pcm_hw_write (sw, buf, len);
 105     sdl_unlock_and_post (s);
 106     return ret;
 107 }
 108
 109 static int AUD_to_sdlfmt (audfmt_e fmt, int *shift)
 110 {
 111     *shift = 0;
 112     switch (fmt) {
 113     case AUD_FMT_S8: return AUDIO_S8;
 114     case AUD_FMT_U8: return AUDIO_U8;
 115     case AUD_FMT_S16: *shift = 1; return AUDIO_S16LSB;
 116     case AUD_FMT_U16: *shift = 1; return AUDIO_U16LSB;
 117     default:
 118         dolog ("Internal logic error: Bad audio format %d\nAborting\n", fmt);
 119         exit (EXIT_FAILURE);
 120     }
 121 }
 122
 123 static int sdl_to_audfmt (int fmt)
 124 {
 125     switch (fmt) {
 126     case AUDIO_S8: return AUD_FMT_S8;
 127     case AUDIO_U8: return AUD_FMT_U8;
 128     case AUDIO_S16LSB: return AUD_FMT_S16;
 129     case AUDIO_U16LSB: return AUD_FMT_U16;
 130     default:
 131         dolog ("Internal logic error: Unrecognized SDL audio format %d\n"
 132                "Aborting\n", fmt);
 133         exit (EXIT_FAILURE);
 134     }
 135 }
 136
 137 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
 138 {
 139     int status;
 140
 141     status = SDL_OpenAudio (req, obt);
 142     if (status) {
 143         dolog ("SDL_OpenAudio failed\nReason: %s\n", errstr ());
 144     }
 145     return status;
 146 }
 147
 148 static void sdl_close (SDLAudioState *s)
 149 {
 150     if (s->initialized) {
 151         sdl_lock (s);
 152         s->exit = 1;
 153         sdl_unlock_and_post (s);
 154         SDL_PauseAudio (1);
 155         SDL_CloseAudio ();
 156         s->initialized = 0;
 157     }
 158 }
 159
 160 static void sdl_callback (void *opaque, Uint8 *buf, int len)
 161 {
 162     SDLVoice *sdl = opaque;
 163     SDLAudioState *s = &glob_sdl;
 164     HWVoice *hw = &sdl->hw;
 165     int samples = len >> hw->shift;
 166
 167     if (s->exit) {
 168         return;
 169     }
 170
 171     while (samples) {
 172         int to_mix, live, decr;
 173
 174         /* dolog ("in callback samples=%d\n", samples); */
 175         sdl_wait (s);
 176         if (s->exit) {
 177             return;
 178         }
 179
 180         sdl_lock (s);
 181         live = pcm_hw_get_live (hw);
 182         if (live <= 0)
 183             goto again;
 184
 185         /* dolog ("in callback live=%d\n", live); */
 186         to_mix = audio_MIN (samples, live);
 187         decr = to_mix;
 188         while (to_mix) {
 189             int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
 190             st_sample_t *src = hw->mix_buf + hw->rpos;
 191
 192             /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
 193             hw->clip (buf, src, chunk);
 194             memset (src, 0, chunk * sizeof (st_sample_t));
 195             hw->rpos = (hw->rpos + chunk) % hw->samples;
 196             to_mix -= chunk;
 197             buf += chunk << hw->shift;
 198         }
 199         samples -= decr;
 200         pcm_hw_dec_live (hw, decr);
 201
 202     again:
 203         sdl_unlock (s);
 204     }
 205     /* dolog ("done len=%d\n", len); */
 206 }
 207
 208 static void sdl_hw_fini (HWVoice *hw)
 209 {
 210     ldebug ("sdl_hw_fini %d fixed=%d\n",
 211              glob_sdl.initialized, audio_conf.fixed_format);
 212     sdl_close (&glob_sdl);
 213 }
 214
 215 static int sdl_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)
 216 {
 217     SDLVoice *sdl = (SDLVoice *) hw;
 218     SDLAudioState *s = &glob_sdl;
 219     SDL_AudioSpec req, obt;
 220     int shift;
 221
 222     ldebug ("sdl_hw_init %d freq=%d fixed=%d\n",
 223             s->initialized, freq, audio_conf.fixed_format);
 224
 225     if (nchannels != 2) {
 226         dolog ("Bogus channel count %d\n", nchannels);
 227         return -1;
 228     }
 229
 230     req.freq = freq;
 231     req.format = AUD_to_sdlfmt (fmt, &shift);
 232     req.channels = nchannels;
 233     req.samples = conf.nb_samples;
 234     shift <<= nchannels == 2;
 235
 236     req.callback = sdl_callback;
 237     req.userdata = sdl;
 238
 239     if (sdl_open (&req, &obt))
 240         return -1;
 241
 242     hw->freq = obt.freq;
 243     hw->fmt = sdl_to_audfmt (obt.format);
 244     hw->nchannels = obt.channels;
 245     hw->bufsize = obt.samples << shift;
 246
 247     s->initialized = 1;
 248     s->exit = 0;
 249     SDL_PauseAudio (0);
 250     return 0;
 251 }
 252
 253 static int sdl_hw_ctl (HWVoice *hw, int cmd, ...)
 254 {
 255     (void) hw;
 256
 257     switch (cmd) {
 258     case VOICE_ENABLE:
 259         SDL_PauseAudio (0);
 260         break;
 261
 262     case VOICE_DISABLE:
 263         SDL_PauseAudio (1);
 264         break;
 265     }
 266     return 0;
 267 }
 268
 269 static void *sdl_audio_init (void)
 270 {
 271     SDLAudioState *s = &glob_sdl;
 272     conf.nb_samples = audio_get_conf_int (QC_SDL_SAMPLES, conf.nb_samples);
 273
 274     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
 275         dolog ("SDL failed to initialize audio subsystem\nReason: %s\n",
 276                errstr ());
 277         return NULL;
 278     }
 279
 280     s->mutex = SDL_CreateMutex ();
 281     if (!s->mutex) {
 282         dolog ("Failed to create SDL mutex\nReason: %s\n", errstr ());
 283         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 284         return NULL;
 285     }
 286
 287     s->sem = SDL_CreateSemaphore (0);
 288     if (!s->sem) {
 289         dolog ("Failed to create SDL semaphore\nReason: %s\n", errstr ());
 290         SDL_DestroyMutex (s->mutex);
 291         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 292         return NULL;
 293     }
 294
 295     return s;
 296 }
 297
 298 static void sdl_audio_fini (void *opaque)
 299 {
 300     SDLAudioState *s = opaque;
 301     sdl_close (s);
 302     SDL_DestroySemaphore (s->sem);
 303     SDL_DestroyMutex (s->mutex);
 304     SDL_QuitSubSystem (SDL_INIT_AUDIO);
 305 }
 306
 307 struct pcm_ops sdl_pcm_ops = {
 308     sdl_hw_init,
 309     sdl_hw_fini,
 310     sdl_hw_run,
 311     sdl_hw_write,
 312     sdl_hw_ctl
 313 };
 314
 315 struct audio_output_driver sdl_output_driver = {
 316     "sdl",
 317     sdl_audio_init,
 318     sdl_audio_fini,
 319     &sdl_pcm_ops,
 320     1,
 321     1,
 322     sizeof (SDLVoice)
 323 };