mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-11-04 18:05:06 +01:00
228 lines
6.8 KiB
C
228 lines
6.8 KiB
C
/****************************************************************************
|
|
* gx_audio.c
|
|
*
|
|
* Genesis Plus GX audio support
|
|
*
|
|
* Copyright Eke-Eke (2007-2012), based on original work from Softdev (2006)
|
|
*
|
|
* Redistribution and use of this code or any derivative works are permitted
|
|
* provided that the following conditions are met:
|
|
*
|
|
* - Redistributions may not be sold, nor may they be used in a commercial
|
|
* product or activity.
|
|
*
|
|
* - Redistributions that are modified from the original source must include the
|
|
* complete source code, including the source code for all components used by a
|
|
* binary built from the modified sources. However, as a special exception, the
|
|
* source code distributed need not include anything that is normally distributed
|
|
* (in either source or binary form) with the major components (compiler, kernel,
|
|
* and so on) of the operating system on which the executable runs, unless that
|
|
* component itself accompanies the executable.
|
|
*
|
|
* - Redistributions must reproduce the above copyright notice, this list of
|
|
* conditions and the following disclaimer in the documentation and/or other
|
|
* materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************************/
|
|
|
|
#include "shared.h"
|
|
|
|
/* Length is dimensionned for at least one frame of emulation */
|
|
#define SOUND_BUFFER_LEN 4096
|
|
|
|
/* Number of sound buffers */
|
|
#define SOUND_BUFFER_NUM 3
|
|
|
|
/* audio DMA status */
|
|
u32 audioStarted;
|
|
|
|
/* DMA soundbuffers (required to be 32-bytes aligned) */
|
|
static u8 soundbuffer[SOUND_BUFFER_NUM][SOUND_BUFFER_LEN] ATTRIBUTE_ALIGN(32);
|
|
|
|
/* Current work soundbuffer */
|
|
static u8 mixbuffer;
|
|
|
|
/* Background music */
|
|
static u8 *Bg_music_ogg = NULL;
|
|
static u32 Bg_music_ogg_size = 0;
|
|
|
|
/* Frame Sync */
|
|
static u8 audio_sync;
|
|
|
|
/***************************************************************************************/
|
|
/* Audio engine */
|
|
/***************************************************************************************/
|
|
|
|
/* Audio DMA callback */
|
|
static void ai_callback(void)
|
|
{
|
|
#ifdef LOG_TIMING
|
|
u64 current = gettime();
|
|
if (prevtime)
|
|
{
|
|
delta_time[frame_cnt] = diff_nsec(prevtime, current);
|
|
frame_cnt = (frame_cnt + 1) % LOGSIZE;
|
|
}
|
|
prevtime = current;
|
|
#endif
|
|
|
|
audio_sync = 0;
|
|
}
|
|
|
|
/* AUDIO engine initialization */
|
|
void gx_audio_Init(void)
|
|
{
|
|
/* Initialize AUDIO processing library (ASNDLIB) */
|
|
/* AUDIO & DSP hardware are initialized */
|
|
/* Default samplerate is set to 48kHz */
|
|
ASND_Init();
|
|
|
|
/* Load background music from FAT device */
|
|
char fname[MAXPATHLEN];
|
|
sprintf(fname,"%s/Bg_music.ogg",DEFAULT_PATH);
|
|
FILE *f = fopen(fname,"rb");
|
|
if (f)
|
|
{
|
|
struct stat filestat;
|
|
stat(fname, &filestat);
|
|
Bg_music_ogg_size = filestat.st_size;
|
|
Bg_music_ogg = memalign(32,Bg_music_ogg_size);
|
|
if (Bg_music_ogg)
|
|
{
|
|
fread(Bg_music_ogg,1,Bg_music_ogg_size,f);
|
|
}
|
|
fclose(f);
|
|
}
|
|
}
|
|
|
|
/* AUDIO engine shutdown */
|
|
void gx_audio_Shutdown(void)
|
|
{
|
|
PauseOgg(1);
|
|
StopOgg();
|
|
ASND_Pause(1);
|
|
ASND_End();
|
|
if (Bg_music_ogg)
|
|
{
|
|
free(Bg_music_ogg);
|
|
}
|
|
}
|
|
|
|
/***
|
|
gx_audio_Update
|
|
|
|
This function retrieves samples for the frame then set the next DMA parameters
|
|
Parameters will be taken in account only when current DMA operation is over
|
|
***/
|
|
int gx_audio_Update(void)
|
|
{
|
|
if (!audio_sync)
|
|
{
|
|
/* Current available soundbuffer */
|
|
s16 *sb = (s16 *)(soundbuffer[mixbuffer]);
|
|
|
|
/* Retrieve audio samples (size must be multiple of 32 bytes) */
|
|
int size = audio_update(sb) * 4;
|
|
|
|
#ifdef LOG_TIMING
|
|
if (prevtime && (frame_cnt < LOGSIZE - 1))
|
|
{
|
|
delta_samp[frame_cnt + 1] = size;
|
|
}
|
|
else
|
|
{
|
|
delta_samp[0] = size;
|
|
}
|
|
#endif
|
|
|
|
/* Update DMA settings */
|
|
DCFlushRange((void *)sb, size);
|
|
AUDIO_InitDMA((u32) sb, size);
|
|
mixbuffer = (mixbuffer + 1) % SOUND_BUFFER_NUM;
|
|
audio_sync = 1;
|
|
|
|
/* Start Audio DMA */
|
|
/* this is called once to kick-off DMA from external memory to audio interface */
|
|
/* DMA operation is automatically restarted when all samples have been sent. */
|
|
/* If DMA settings are not updated at that time, previous sound buffer will be used. */
|
|
/* Therefore we need to make sure frame emulation is completed before current DMA is */
|
|
/* completed, by synchronizing frame emulation with DMA start and also by syncing it */
|
|
/* with Video Interrupt and outputing a suitable number of samples per frame. */
|
|
if (!audioStarted)
|
|
{
|
|
/* restart audio DMA */
|
|
AUDIO_StopDMA();
|
|
AUDIO_StartDMA();
|
|
audioStarted = 1;
|
|
}
|
|
|
|
return SYNC_AUDIO;
|
|
}
|
|
|
|
return NO_SYNC;
|
|
}
|
|
|
|
/***
|
|
gx_audio_Start
|
|
|
|
This function restart the audio engine
|
|
This is called when coming back from Main Menu
|
|
***/
|
|
void gx_audio_Start(void)
|
|
{
|
|
/* shutdown background music */
|
|
PauseOgg(1);
|
|
StopOgg();
|
|
|
|
/* shutdown menu audio processing */
|
|
ASND_Pause(1);
|
|
ASND_End();
|
|
AUDIO_StopDMA();
|
|
AUDIO_RegisterDMACallback(NULL);
|
|
DSP_Halt();
|
|
|
|
/* DMA Interrupt callback */
|
|
AUDIO_RegisterDMACallback(ai_callback);
|
|
|
|
/* reset emulation audio processing */
|
|
memset(soundbuffer, 0, 3 * SOUND_BUFFER_LEN);
|
|
audioStarted = 0;
|
|
mixbuffer = 0;
|
|
audio_sync = 0;
|
|
}
|
|
|
|
/***
|
|
gx_audio_Stop
|
|
|
|
This function stops current Audio DMA process
|
|
This is called when going back to Main Menu
|
|
DMA need to be restarted when going back to the game (see above)
|
|
***/
|
|
void gx_audio_Stop(void)
|
|
{
|
|
/* restart menu audio processing */
|
|
DSP_Unhalt();
|
|
ASND_Init();
|
|
ASND_Pause(0);
|
|
|
|
/* play background music */
|
|
if (Bg_music_ogg && !Shutdown)
|
|
{
|
|
PauseOgg(0);
|
|
PlayOgg((char *)Bg_music_ogg, Bg_music_ogg_size, 0, OGG_INFINITE_TIME);
|
|
SetVolumeOgg(((int)config.bgm_volume * 255) / 100);
|
|
}
|
|
}
|