Пример #1
0
static void *alsa_thread_init(const char *device,
      unsigned rate, unsigned latency)
{
   snd_pcm_uframes_t buffer_size;
   snd_pcm_format_t format;
   snd_pcm_hw_params_t *params    = NULL;
   snd_pcm_sw_params_t *sw_params = NULL;
   const char *alsa_dev           = device ? device : "default";
   unsigned latency_usec          = latency * 1000 / 2;
   unsigned channels              = 2;
   unsigned periods               = 4;
   alsa_thread_t            *alsa = (alsa_thread_t*)
      calloc(1, sizeof(alsa_thread_t));

   if (!alsa)
      return NULL;

   TRY_ALSA(snd_pcm_open(&alsa->pcm, alsa_dev, SND_PCM_STREAM_PLAYBACK, 0));

   TRY_ALSA(snd_pcm_hw_params_malloc(&params));
   alsa->has_float = alsathread_find_float_format(alsa->pcm, params);
   format = alsa->has_float ? SND_PCM_FORMAT_FLOAT : SND_PCM_FORMAT_S16;

   TRY_ALSA(snd_pcm_hw_params_any(alsa->pcm, params));
   TRY_ALSA(snd_pcm_hw_params_set_access(
            alsa->pcm, params, SND_PCM_ACCESS_RW_INTERLEAVED));
   TRY_ALSA(snd_pcm_hw_params_set_format(alsa->pcm, params, format));
   TRY_ALSA(snd_pcm_hw_params_set_channels(alsa->pcm, params, channels));
   TRY_ALSA(snd_pcm_hw_params_set_rate(alsa->pcm, params, rate, 0));

   TRY_ALSA(snd_pcm_hw_params_set_buffer_time_near(
            alsa->pcm, params, &latency_usec, NULL));
   TRY_ALSA(snd_pcm_hw_params_set_periods_near(
            alsa->pcm, params, &periods, NULL));

   TRY_ALSA(snd_pcm_hw_params(alsa->pcm, params));

   /* Shouldn't have to bother with this, 
    * but some drivers are apparently broken. */
   if (snd_pcm_hw_params_get_period_size(params, &alsa->period_frames, NULL))
      snd_pcm_hw_params_get_period_size_min(
            params, &alsa->period_frames, NULL);
   RARCH_LOG("ALSA: Period size: %d frames\n", (int)alsa->period_frames);
   if (snd_pcm_hw_params_get_buffer_size(params, &buffer_size))
      snd_pcm_hw_params_get_buffer_size_max(params, &buffer_size);
   RARCH_LOG("ALSA: Buffer size: %d frames\n", (int)buffer_size);

   alsa->buffer_size = snd_pcm_frames_to_bytes(alsa->pcm, buffer_size);
   alsa->period_size = snd_pcm_frames_to_bytes(alsa->pcm, alsa->period_frames);

   TRY_ALSA(snd_pcm_sw_params_malloc(&sw_params));
   TRY_ALSA(snd_pcm_sw_params_current(alsa->pcm, sw_params));
   TRY_ALSA(snd_pcm_sw_params_set_start_threshold(
            alsa->pcm, sw_params, buffer_size / 2));
   TRY_ALSA(snd_pcm_sw_params(alsa->pcm, sw_params));

   snd_pcm_hw_params_free(params);
   snd_pcm_sw_params_free(sw_params);

   alsa->fifo_lock = slock_new();
   alsa->cond_lock = slock_new();
   alsa->cond = scond_new();
   alsa->buffer = fifo_new(alsa->buffer_size);
   if (!alsa->fifo_lock || !alsa->cond_lock || !alsa->cond || !alsa->buffer)
      goto error;

   alsa->worker_thread = sthread_create(alsa_worker_thread, alsa);
   if (!alsa->worker_thread)
   {
      RARCH_ERR("error initializing worker thread");
      goto error;
   }

   return alsa;

error:
   RARCH_ERR("ALSA: Failed to initialize...\n");
   if (params)
      snd_pcm_hw_params_free(params);

   if (sw_params)
      snd_pcm_sw_params_free(sw_params);

   alsa_thread_free(alsa);

   return NULL;
}
Пример #2
0
static void *alsa_init(const char *device, unsigned rate, unsigned latency)
{
   alsa_t *alsa = (alsa_t*)calloc(1, sizeof(alsa_t));
   if (!alsa)
      return NULL;

   snd_pcm_hw_params_t *params = NULL;
   snd_pcm_sw_params_t *sw_params = NULL;

   unsigned latency_usec = latency * 1000;
   unsigned channels = 2;
   unsigned periods = 4;
   snd_pcm_format_t format;

   const char *alsa_dev = "default";
   if (device)
      alsa_dev = device;

   snd_pcm_uframes_t buffer_size;

   TRY_ALSA(snd_pcm_open(&alsa->pcm, alsa_dev, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK));
   TRY_ALSA(snd_pcm_hw_params_malloc(&params));
   alsa->has_float = find_float_format(alsa->pcm, params);
   format = alsa->has_float ? SND_PCM_FORMAT_FLOAT : SND_PCM_FORMAT_S16;

   TRY_ALSA(snd_pcm_hw_params_any(alsa->pcm, params));
   TRY_ALSA(snd_pcm_hw_params_set_access(alsa->pcm, params, SND_PCM_ACCESS_RW_INTERLEAVED));
   TRY_ALSA(snd_pcm_hw_params_set_format(alsa->pcm, params, format));
   TRY_ALSA(snd_pcm_hw_params_set_channels(alsa->pcm, params, channels));
   TRY_ALSA(snd_pcm_hw_params_set_rate(alsa->pcm, params, rate, 0));

   TRY_ALSA(snd_pcm_hw_params_set_buffer_time_near(alsa->pcm, params, &latency_usec, NULL));
   TRY_ALSA(snd_pcm_hw_params_set_periods_near(alsa->pcm, params, &periods, NULL));

   TRY_ALSA(snd_pcm_hw_params(alsa->pcm, params));

   snd_pcm_hw_params_get_period_size(params, &buffer_size, NULL);
   RARCH_LOG("ALSA: Period size: %d frames\n", (int)buffer_size);
   snd_pcm_hw_params_get_buffer_size(params, &buffer_size);
   RARCH_LOG("ALSA: Buffer size: %d frames\n", (int)buffer_size);
   alsa->buffer_size = snd_pcm_frames_to_bytes(alsa->pcm, buffer_size);
   alsa->can_pause = snd_pcm_hw_params_can_pause(params);
   RARCH_LOG("ALSA: Can pause: %s.\n", alsa->can_pause ? "yes" : "no");

   TRY_ALSA(snd_pcm_sw_params_malloc(&sw_params));
   TRY_ALSA(snd_pcm_sw_params_current(alsa->pcm, sw_params));
   TRY_ALSA(snd_pcm_sw_params_set_start_threshold(alsa->pcm, sw_params, buffer_size / 2));
   TRY_ALSA(snd_pcm_sw_params(alsa->pcm, sw_params));

   snd_pcm_hw_params_free(params);
   snd_pcm_sw_params_free(sw_params);

   return alsa;

error:
   RARCH_ERR("ALSA: Failed to initialize...\n");
   if (params)
      snd_pcm_hw_params_free(params);

   if (sw_params)
      snd_pcm_sw_params_free(sw_params);

   if (alsa)
   {
      if (alsa->pcm)
         snd_pcm_close(alsa->pcm);

      free(alsa);
   }
   return NULL;
}