RetroArch/audio/alsathread.c
2013-01-04 15:02:40 -05:00

316 lines
8.2 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - Hans-Kristian Arntzen
* Copyright (C) 2012-2013 - Michael Lelli
*
* 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,
};