int device_start_sn764xx(UINT8 ChipID, int clock, int shiftregwidth, int noisetaps,
int negate, int stereo, int clockdivider, int freq0)
{
sn764xx_state *info;
int rate;
if (ChipID >= MAX_CHIPS)
return 0;
info = &SN764xxData[ChipID];
/* emulator create */
switch(EMU_CORE)
{
case EC_MAME:
rate = sn76496_start(&info->chip, clock, shiftregwidth, noisetaps,
negate, stereo, clockdivider, freq0);
sn76496_freq_limiter(clock & 0x3FFFFFFF, clockdivider, SampleRate);
break;
#ifdef ENABLE_ALL_CORES
case EC_MAXIM:
rate = SampleRate;
info->chip = SN76489_Init(clock, rate);
if (info->chip == NULL)
return 0;
SN76489_Config((SN76489_Context*)info->chip, noisetaps, shiftregwidth, 0);
break;
#endif
}
return rate;
}
int device_start_sn764xx(void **_info, int EMU_CORE, int clock, int SampleRate, int shiftregwidth, int noisetaps,
int negate, int stereo, int clockdivider, int freq0)
{
sn764xx_state *info;
int rate;
#ifdef ENABLE_ALL_CORES
if (EMU_CORE >= 0x02)
EMU_CORE = EC_MAME;
#else
EMU_CORE = EC_MAME;
#endif
info = (sn764xx_state*) calloc(1, sizeof(sn764xx_state));
*_info = (void *) info;
/* emulator create */
info->EMU_CORE = EMU_CORE;
switch(EMU_CORE)
{
case EC_MAME:
rate = sn76496_start(&info->chip, clock, shiftregwidth, noisetaps,
negate, stereo, clockdivider, freq0);
sn76496_freq_limiter(clock & 0x3FFFFFFF, clockdivider, SampleRate);
break;
#ifdef ENABLE_ALL_CORES
case EC_MAXIM:
rate = SampleRate;
info->chip = SN76489_Init(clock, rate);
if (info->chip == NULL)
return 0;
SN76489_Config((SN76489_Context*)info->chip, noisetaps, shiftregwidth, 0);
break;
#endif
}
return rate;
}
/* Initialize sound chips emulation */
void sound_init(void)
{
/* Number of M-cycles executed per second. */
/* */
/* All emulated chips are kept in sync by using a common oscillator (MCLOCK) */
/* */
/* The original console would run exactly 53693175 M-cycles (53203424 for PAL), with */
/* 3420 M-cycles per line and 262 (313 for PAL) lines per frame, which gives an exact */
/* framerate of 59.92 (49.70 for PAL) fps. */
/* */
/* Since audio samples are generated at the end of the frame, to prevent audio skipping */
/* or lag between emulated frames, number of samples rendered per frame must be set to */
/* output samplerate (number of samples played per second) divided by output framerate */
/* (number of frames emulated per seconds). */
/* */
/* On some systems, we may want to achieve 100% smooth video rendering by synchronizing */
/* frame emulation with VSYNC, which frequency is generally not exactly those values. */
/* In that case, number of frames emulated per seconds is the same as the number of */
/* frames rendered per seconds by the host system video hardware. */
/* */
/* When no framerate is specified, base clock is original master clock value. */
/* Otherwise, it is based on the output framerate. */
/* */
double mclk = snd.frame_rate ? (MCYCLES_PER_LINE * lines_per_frame * snd.frame_rate) : system_clock;
/* For maximal accuracy, sound chips run in synchronization with 68k and Z80 cpus */
/* These values give the exact number of M-cycles executed per internal sample clock: */
/* . PSG chip runs at original rate and audio is resampled internally after each update */
/* . FM chips run by default (if HQ mode disabled) at the output rate directly */
/* We use 21.11 fixed point precision (max. mcycle value is 3420*313 i.e 21 bits max) */
psg_cycles_ratio = 16 * 15 * (1 << 11);
fm_cycles_ratio = (unsigned int)(mclk / (double) snd.sample_rate * 2048.0);
psg_cycles_count = 0;
fm_cycles_count = 0;
/* Initialize PSG core (input clock should be based on emulated system clock) */
SN76489_Init(mclk/15.0,snd.sample_rate);
/* Initialize FM cores (input clock and samplerate are only used when HQ mode is disabled) */
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
/* YM2612 */
YM2612Init(mclk/7.0,snd.sample_rate);
YM_Reset = YM2612ResetChip;
YM_Update = YM2612Update;
YM_Write = YM2612Write;
/* In HQ mode, YM2612 is running at original rate (one sample each 144*7 M-cycles) */
/* Audio is resampled externally at the end of a frame. */
if (config.hq_fm)
{
fm_cycles_ratio = 144 * 7 * (1 << 11);
Fir_Resampler_time_ratio(mclk / (double)snd.sample_rate / (144.0 * 7.0), config.rolloff);
}
}
else
{
/* YM2413 */
YM2413Init(mclk/15.0,snd.sample_rate);
YM_Reset = YM2413ResetChip;
YM_Update = YM2413Update;
YM_Write = YM2413Write;
/* In HQ mode, YM2413 is running at original rate (one sample each 72*15 M-cycles) */
/* Audio is resampled externally at the end of a frame. */
if (config.hq_fm)
{
fm_cycles_ratio = 72 * 15 * (1 << 11);
Fir_Resampler_time_ratio(mclk / (double)snd.sample_rate / (72.0 * 15.0), config.rolloff);
}
}
#ifdef LOGSOUND
error("%f mcycles per second\n", mclk);
error("%d mcycles per PSG sample\n", psg_cycles_ratio);
error("%d mcycles per FM sample\n", fm_cycles_ratio);
#endif
}
int sound_init(void)
{
uint8 *buf = NULL;
int restore_fm = 0;
int i;
/* Save register settings */
if(snd.enabled && sms.use_fm)
{
restore_fm = 1;
buf = malloc(FM_GetContextSize());
FM_GetContext(buf);
}
/* If we are reinitializing, shut down sound emulation */
if(snd.enabled)
{
sound_shutdown();
}
/* Disable sound until initialization is complete */
snd.enabled = 0;
/* Check if sample rate is invalid */
if(snd.sample_rate < 8000 || snd.sample_rate > 48000)
return 0;
/* Assign stream mixing callback if none provided */
if(!snd.mixer_callback)
snd.mixer_callback = sound_mixer_callback;
/* Calculate number of samples generated per frame */
#ifdef PSP
/* PSP version requires a sample count divisible by 64 */
snd.sample_count = ((snd.sample_rate / snd.fps) + 63) & ~63;
#else
snd.sample_count = (snd.sample_rate / snd.fps);
#endif
/* Calculate size of sample buffer */
snd.buffer_size = snd.sample_count * 2;
/* Free sample buffer position table if previously allocated */
if(smptab)
{
free(smptab);
smptab = NULL;
}
/* Prepare incremental info */
snd.done_so_far = 0;
smptab_len = (sms.display == DISPLAY_NTSC) ? 262 : 313;
smptab = malloc(smptab_len * sizeof(int));
if(!smptab) return 0;
for (i = 0; i < smptab_len; i++)
{
double calc = (snd.sample_count * i);
calc = calc / (double)smptab_len;
smptab[i] = (int)calc;
}
/* Allocate emulated sound streams */
for(i = 0; i < STREAM_MAX; i++)
{
snd.stream[i] = malloc(snd.buffer_size);
if(!snd.stream[i]) return 0;
memset(snd.stream[i], 0, snd.buffer_size);
}
/* Allocate sound output streams */
snd.output[0] = calloc(snd.sample_count, sizeof(int16));
snd.output[1] = calloc(snd.sample_count, sizeof(int16));
if(!snd.output[0] || !snd.output[1]) return 0;
/* Set up buffer pointers */
fm_buffer = (int16 **)&snd.stream[STREAM_FM_MO];
psg_buffer = (int16 **)&snd.stream[STREAM_PSG_L];
/* Set up SN76489 emulation */
SN76489_Init(0, snd.psg_clock, snd.sample_rate);
/* Set up YM2413 emulation */
FM_Init();
/* Inform other functions that we can use sound */
snd.enabled = 1;
/* Restore YM2413 register settings */
if(restore_fm)
{
FM_SetContext(buf);
}
return 1;
}
int audio_init(int samplerate, double framerate)
{
/* Number of M-cycles executed per second. */
/* All emulated chips are kept in sync by using a common oscillator (MCLOCK) */
/* */
/* The original console would run exactly 53693175 M-cycles per sec (53203424 for PAL), */
/* 3420 M-cycles per line and 262 (313 for PAL) lines per frame, which gives an exact */
/* framerate of 59.92 (49.70 for PAL) frames per second. */
/* */
/* Since audio samples are generated at the end of the frame, to prevent audio skipping */
/* or lag between emulated frames, number of samples rendered per frame must be set to */
/* output samplerate (number of samples played per second) divided by input framerate */
/* (number of frames emulated per seconds). */
/* */
/* On some systems, we may want to achieve 100% smooth video rendering by synchronizing */
/* frame emulation with VSYNC, which frequency is generally not exactly those values. */
/* In that case, input framerate (number of frames emulated per seconds) is the same as */
/* output framerate (number of frames rendered per seconds) by the host video hardware. */
/* */
/* When no framerate is specified, base clock is set to original master clock value. */
/* Otherwise, it is set to number of M-cycles emulated per line (fixed) multiplied by */
/* number of lines per frame (VDP mode specific) multiplied by input framerate. */
/* */
double mclk = framerate ? (MCYCLES_PER_LINE * (vdp_pal ? 313 : 262) * framerate) : system_clock;
/* Shutdown first */
audio_shutdown();
/* Clear the sound data context */
memset(&snd, 0, sizeof (snd));
/* Initialize audio rates */
snd.sample_rate = samplerate;
snd.frame_rate = framerate;
/* Initialize Blip Buffers */
snd.blips[0][0] = blip_new(samplerate / 10);
snd.blips[0][1] = blip_new(samplerate / 10);
if (!snd.blips[0][0] || !snd.blips[0][1])
{
audio_shutdown();
return -1;
}
/* For maximal accuracy, sound chips are running at their original rate using common */
/* master clock timebase so they remain perfectly synchronized together, while still */
/* being synchronized with 68K and Z80 CPUs as well. Mixed sound chip output is then */
/* resampled to desired rate at the end of each frame, using Blip Buffer. */
blip_set_rates(snd.blips[0][0], mclk, samplerate);
blip_set_rates(snd.blips[0][1], mclk, samplerate);
/* Initialize PSG core */
SN76489_Init(snd.blips[0][0], snd.blips[0][1], (system_hw < SYSTEM_MARKIII) ? SN_DISCRETE : SN_INTEGRATED);
/* Mega CD sound hardware */
if (system_hw == SYSTEM_MCD)
{
/* allocate blip buffers */
snd.blips[1][0] = blip_new(samplerate / 10);
snd.blips[1][1] = blip_new(samplerate / 10);
snd.blips[2][0] = blip_new(samplerate / 10);
snd.blips[2][1] = blip_new(samplerate / 10);
if (!snd.blips[1][0] || !snd.blips[1][1] || !snd.blips[2][0] || !snd.blips[2][1])
{
audio_shutdown();
return -1;
}
/* Initialize PCM core */
pcm_init(snd.blips[1][0], snd.blips[1][1]);
/* Initialize CDD core */
cdd_init(snd.blips[2][0], snd.blips[2][1]);
}
/* Set audio enable flag */
snd.enabled = 1;
/* Reset audio */
audio_reset();
return (0);
}
