RetroArch/wii/audio.c
2011-12-14 21:44:03 +01:00

150 lines
3.7 KiB
C

/* SSNES - A Super Nintendo Entertainment System (SNES) Emulator frontend for libsnes.
* Copyright (C) 2010-2011 - Hans-Kristian Arntzen
*
* Some code herein may be based on code found in BSNES.
*
* SSNES 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.
*
* SSNES 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 SSNES.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "../driver.h"
#include <stdlib.h>
#include <stdbool.h>
#include "../general.h"
#include <malloc.h>
#include <string.h>
#include <gccore.h>
#include <ogcsys.h>
#define CHUNK_FRAMES 256
#define CHUNK_SIZE (CHUNK_FRAMES * sizeof(uint32_t))
#define BLOCKS 4
typedef struct
{
uint32_t data[BLOCKS][CHUNK_FRAMES];
volatile unsigned dma_busy;
volatile unsigned dma_next;
volatile unsigned dma_write;
size_t write_ptr;
lwpq_t cond;
bool nonblock;
} wii_audio_t;
static wii_audio_t *g_audio;
static void dma_callback(void)
{
g_audio->dma_busy = g_audio->dma_next;
g_audio->dma_next = (g_audio->dma_next + 1) & (BLOCKS - 1);
DCFlushRange(g_audio->data[g_audio->dma_next], CHUNK_SIZE);
AUDIO_InitDMA((u32)g_audio->data[g_audio->dma_next], CHUNK_SIZE);
LWP_ThreadSignal(g_audio->cond);
}
static void *wii_audio_init(const char *device, unsigned rate, unsigned latency)
{
static bool inited = false;
if (!inited)
{
AUDIO_Init(NULL);
AUDIO_SetDSPSampleRate(AI_SAMPLERATE_48KHZ);
g_settings.audio.out_rate = 48000;
AUDIO_RegisterDMACallback(dma_callback);
inited = true;
}
g_audio = memalign(32, sizeof(*g_audio));
memset(g_audio, 0, sizeof(*g_audio));
LWP_InitQueue(&g_audio->cond);
g_audio->dma_write = BLOCKS - 1;
DCFlushRange(g_audio->data, sizeof(g_audio->data));
AUDIO_InitDMA((u32)g_audio->data[g_audio->dma_next], CHUNK_SIZE);
AUDIO_StartDMA();
return g_audio;
}
static ssize_t wii_audio_write(void *data, const void *buf_, size_t size)
{
wii_audio_t *wa = data;
size_t frames = size >> 2;
const uint32_t *buf = buf_;
while (frames)
{
size_t to_write = CHUNK_FRAMES - wa->write_ptr;
if (frames < to_write)
to_write = frames;
while ((wa->dma_write == wa->dma_next || wa->dma_write == wa->dma_busy) && !wa->nonblock)
LWP_ThreadSleep(wa->cond);
memcpy(wa->data[wa->dma_write] + wa->write_ptr, buf, to_write * sizeof(uint32_t));
wa->write_ptr += to_write;
frames -= to_write;
buf += to_write;
if (wa->write_ptr >= CHUNK_FRAMES)
{
wa->write_ptr -= CHUNK_FRAMES;
wa->dma_write = (wa->dma_write + 1) & (BLOCKS - 1);
}
}
return size;
}
static bool wii_audio_stop(void *data)
{
(void)data;
AUDIO_StopDMA();
return true;
}
static void wii_audio_set_nonblock_state(void *data, bool state)
{
wii_audio_t *wa = data;
wa->nonblock = state;
}
static bool wii_audio_start(void *data)
{
(void)data;
AUDIO_StartDMA();
return true;
}
static void wii_audio_free(void *data)
{
AUDIO_StopDMA();
if (data)
free(data);
g_audio = NULL;
}
const audio_driver_t audio_wii = {
.init = wii_audio_init,
.write = wii_audio_write,
.stop = wii_audio_stop,
.start = wii_audio_start,
.set_nonblock_state = wii_audio_set_nonblock_state,
.free = wii_audio_free,
.ident = "wii"
};