make alsathread a seperate audio driver

Makefile

@@ -107,7 +107,7 @@ ifeq ($(HAVE_OSS_LIB), 1)
 endif
 
 ifeq ($(HAVE_ALSA), 1)
-   OBJ += audio/alsa.o
+   OBJ += audio/alsa.o audio/alsathread.o
    LIBS += $(ALSA_LIBS)
    DEFINES += $(ALSA_CFLAGS)
 endif

audio/alsathread.c

@@ -0,0 +1,314 @@
+/*  RetroArch - A frontend for libretro.
+ *  Copyright (C) 2010-2012 - Hans-Kristian Arntzen
+ * 
+ *  RetroArch is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with RetroArch.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "../driver.h"
+#include <stdlib.h>
+#include <asoundlib.h>
+#include "../general.h"
+#include "../thread.h"
+#include "../fifo_buffer.h"
+
+#define TRY_ALSA(x) if (x < 0) { \
+                  goto error; \
+               }
+
+typedef struct alsa
+{
+   snd_pcm_t *pcm;
+   bool nonblock;
+   bool has_float;
+   volatile bool thread_dead;
+
+   size_t buffer_size;
+   size_t period_size;
+   snd_pcm_uframes_t period_frames;
+
+   fifo_buffer_t *buffer;
+   sthread_t *worker_thread;
+   slock_t *fifo_lock;
+   scond_t *cond;
+   slock_t *cond_lock;
+} alsa_t;
+
+static void alsa_worker_thread(void *data)
+{
+   alsa_t *alsa = (alsa_t*)data;
+
+   uint8_t *buf = (uint8_t *)calloc(1, alsa->period_size);
+   if (!buf)
+   {
+      RARCH_ERR("failed to allocate audio buffer");
+      goto end;
+   }
+
+   while (!alsa->thread_dead)
+   {
+      slock_lock(alsa->fifo_lock);
+      size_t avail = fifo_read_avail(alsa->buffer);
+      size_t fifo_size = min(alsa->period_size, avail);
+      fifo_read(alsa->buffer, buf, fifo_size);
+      scond_signal(alsa->cond);
+      slock_unlock(alsa->fifo_lock);
+
+      // If underrun, fill rest with silence.
+      memset(buf + fifo_size, 0, alsa->period_size - fifo_size);
+
+      snd_pcm_sframes_t frames = snd_pcm_writei(alsa->pcm, buf, alsa->period_frames);
+
+      if (frames == -EPIPE || frames == -EINTR || frames == -ESTRPIPE)
+      {
+         if (snd_pcm_recover(alsa->pcm, frames, 1) < 0)
+         {
+            RARCH_ERR("[ALSA]: (#2) Failed to recover from error (%s)\n",
+                  snd_strerror(frames));
+            break;
+         }
+
+         continue;
+      }
+      else if (frames < 0)
+      {
+         RARCH_ERR("[ALSA]: Unknown error occured (%s).\n", snd_strerror(frames));
+         break;
+      }
+   }
+
+end:
+   slock_lock(alsa->cond_lock);
+   alsa->thread_dead = true;
+   scond_signal(alsa->cond);
+   slock_unlock(alsa->cond_lock);
+   free(buf);
+}
+
+static bool alsa_use_float(void *data)
+{
+   alsa_t *alsa = (alsa_t*)data;
+   return alsa->has_float;
+}
+
+static bool find_float_format(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
+{
+   if (snd_pcm_hw_params_test_format(pcm, params, SND_PCM_FORMAT_FLOAT) == 0)
+   {
+      RARCH_LOG("ALSA: Using floating point format.\n");
+      return true;
+   }
+   RARCH_LOG("ALSA: Using signed 16-bit format.\n");
+   return false;
+}
+
+static void alsa_free(void *data)
+{
+   alsa_t *alsa = (alsa_t*)data;
+
+   if (alsa)
+   {
+      if (alsa->worker_thread)
+      {
+         alsa->thread_dead = true;
+         sthread_join(alsa->worker_thread);
+      }
+      if (alsa->buffer)
+         fifo_free(alsa->buffer);
+      if (alsa->cond)
+         scond_free(alsa->cond);
+      if (alsa->fifo_lock)
+         slock_free(alsa->fifo_lock);
+      if (alsa->cond_lock)
+         slock_free(alsa->cond_lock);
+      if (alsa->pcm)
+      {
+         snd_pcm_drop(alsa->pcm);
+         snd_pcm_close(alsa->pcm);
+      }
+      free(alsa);
+   }
+}
+
+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;
+
+   const char *alsa_dev = "default";
+   if (device)
+      alsa_dev = device;
+
+   unsigned latency_usec = latency * 1000 / 2;
+
+   unsigned channels = 2;
+   unsigned periods = 4;
+   snd_pcm_uframes_t buffer_size;
+   snd_pcm_format_t format;
+
+   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 = 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, &alsa->period_frames, NULL);
+   RARCH_LOG("ALSA: Period size: %d frames\n", (int)alsa->period_frames);
+   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->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_free(alsa);
+
+   return NULL;
+}
+
+static ssize_t alsa_write(void *data, const void *buf, size_t size)
+{
+   alsa_t *alsa = (alsa_t*)data;
+
+   if (alsa->thread_dead)
+      return -1;
+
+   if (alsa->nonblock)
+   {
+      slock_lock(alsa->fifo_lock);
+      size_t avail = fifo_write_avail(alsa->buffer);
+      size_t write_amt = min(avail, size);
+      fifo_write(alsa->buffer, buf, write_amt);
+      slock_unlock(alsa->fifo_lock);
+      return write_amt;
+   }
+   else
+   {
+      size_t written = 0;
+      while (written < size && !alsa->thread_dead)
+      {
+         slock_lock(alsa->fifo_lock);
+         size_t avail = fifo_write_avail(alsa->buffer);
+
+         if (avail == 0)
+         {
+            slock_unlock(alsa->fifo_lock);
+            slock_lock(alsa->cond_lock);
+            if (!alsa->thread_dead)
+               scond_wait(alsa->cond, alsa->cond_lock);
+            slock_unlock(alsa->cond_lock);
+         }
+         else
+         {
+            size_t write_amt = min(size - written, avail);
+            fifo_write(alsa->buffer, (const char*)buf + written, write_amt);
+            slock_unlock(alsa->fifo_lock);
+            written += write_amt;
+         }
+      }
+      return written;
+   }
+}
+
+static bool alsa_stop(void *data)
+{
+   (void)data;
+   return true;
+}
+
+static void alsa_set_nonblock_state(void *data, bool state)
+{
+   alsa_t *alsa = (alsa_t*)data;
+   alsa->nonblock = state;
+}
+
+static bool alsa_start(void *data)
+{
+   (void)data;
+   return true;
+}
+
+static size_t alsa_write_avail(void *data)
+{
+   alsa_t *alsa = (alsa_t*)data;
+
+   if (alsa->thread_dead)
+      return 0;
+   slock_lock(alsa->fifo_lock);
+   size_t val = fifo_write_avail(alsa->buffer);
+   slock_unlock(alsa->fifo_lock);
+   return val;
+}
+
+static size_t alsa_buffer_size(void *data)
+{
+   alsa_t *alsa = (alsa_t*)data;
+   return alsa->buffer_size;
+}
+
+const audio_driver_t audio_alsathread = {
+   alsa_init,
+   alsa_write,
+   alsa_stop,
+   alsa_start,
+   alsa_set_nonblock_state,
+   alsa_free,
+   alsa_use_float,
+   "alsathread",
+   alsa_write_avail,
+   alsa_buffer_size,
+};

config.def.h

@@ -46,6 +46,7 @@ enum
    AUDIO_RSOUND,
    AUDIO_OSS,
    AUDIO_ALSA,
+   AUDIO_ALSATHREAD,
    AUDIO_ROAR,
    AUDIO_AL,
    AUDIO_SL,
@@ -109,6 +110,8 @@ enum
 #define AUDIO_DEFAULT_DRIVER AUDIO_XDK360
 #elif defined(GEKKO)
 #define AUDIO_DEFAULT_DRIVER AUDIO_WII
+#elif defined(HAVE_ALSA) && defined(HAVE_VIDEOCORE)
+#define AUDIO_DEFAULT_DRIVER AUDIO_ALSATHREAD
 #elif defined(HAVE_ALSA)
 #define AUDIO_DEFAULT_DRIVER AUDIO_ALSA
 #elif defined(HAVE_PULSE)

driver.c

@@ -33,6 +33,7 @@
 static const audio_driver_t *audio_drivers[] = {
 #ifdef HAVE_ALSA
    &audio_alsa,
+   &audio_alsathread,
 #endif
 #if defined(HAVE_OSS) || defined(HAVE_OSS_BSD)
    &audio_oss,

driver.h

@@ -322,6 +322,7 @@ extern driver_t driver;
 extern const audio_driver_t audio_rsound;
 extern const audio_driver_t audio_oss;
 extern const audio_driver_t audio_alsa;
+extern const audio_driver_t audio_alsathread;
 extern const audio_driver_t audio_roar;
 extern const audio_driver_t audio_openal;
 extern const audio_driver_t audio_opensl;

settings.c

@@ -43,6 +43,8 @@ const char *config_get_default_audio(void)
          return "oss";
       case AUDIO_ALSA:
          return "alsa";
+      case AUDIO_ALSATHREAD:
+         return "alsathread";
       case AUDIO_ROAR:
          return "roar";
       case AUDIO_COREAUDIO: