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improved FM & PSG chip synchronization when using resampling (fixes buffers overflow issues and problems with DAC timings that occured with previous "fix")

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ekeeke31 2010-02-15 14:02:37 +00:00
parent cea89b4531
commit 27d3fc5328
1 changed files with 26 additions and 31 deletions
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55
source/sound/sound.c
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@ -33,9 +33,6 @@ static unsigned int fm_cycles_count;
/* Run FM chip for required M-cycles */
static inline void fm_update(unsigned int cycles)
{
/* convert to 21.11 fixed point */
cycles <<= 11;
if (cycles > fm_cycles_count)
{
/* period to run */
@ -76,9 +73,6 @@ static inline void fm_update(unsigned int cycles)
/* Run PSG chip for required M-cycles */
static inline void psg_update(unsigned int cycles)
{
/* convert to 21.11 fixed point */
cycles <<= 11;
if (cycles > psg_cycles_count)
{
/* period to run */
@ -145,7 +139,7 @@ void sound_init(void)
if (config.hq_fm)
{
fm_cycles_ratio = 144 * 7 * (1 << 11);
Fir_Resampler_time_ratio(mclk / (double)snd.sample_rate / (144.0 * 7.0));
Fir_Resampler_time_ratio(mclk / (double)snd.sample_rate / (144.0 * 7.0), config.rolloff);
}
#ifdef LOGSOUND
@ -166,10 +160,11 @@ void sound_reset(void)
/* End of frame update, return the number of samples run so far. */
int sound_update(unsigned int cycles)
{
/* run PSG chip until end of frame */
/* run PSG & FM chips until end of frame */
cycles <<= 11;
psg_update(cycles);
fm_update(cycles);
/* number of available samples */
int size = snd.psg.pos - snd.psg.buffer;
#ifdef LOGSOUND
@ -179,30 +174,30 @@ int sound_update(unsigned int cycles)
/* FM resampling */
if (config.hq_fm)
{
/* get remaining FM samples */
int remain = Fir_Resampler_input_needed(size);
/* get available FM samples */
int avail = Fir_Resampler_avail();
if (remain > 0)
{
/* resynchronize FM & PSG chips */
YM2612Update(Fir_Resampler_buffer(), remain);
Fir_Resampler_write(remain << 1);
fm_cycles_count = psg_cycles_count;
}
#ifdef LOGSOUND
error("%d FM samples available (%d needed)\n",Fir_Resampler_written() >> 1, remain);
#endif
if (avail < size)
{
/* FM chip is late for one sample */
YM2612Update(Fir_Resampler_buffer(), 1);
Fir_Resampler_write(2);
fm_cycles_count += fm_cycles_ratio;
}
else
{
/* run FM chip until end of frame */
fm_update(cycles);
/* FM chip is ahead */
fm_cycles_count += (avail - size) * psg_cycles_ratio;
}
}
#ifdef LOGSOUND
if (config.hq_fm)
error("%d FM samples (%d) available\n",Fir_Resampler_avail(), Fir_Resampler_written() >> 1);
else
error("%d FM samples available\n",(snd.fm.pos - snd.fm.buffer)>>1);
#endif
}
#ifdef LOGSOUND
error("%lu PSG cycles run\n",psg_cycles_count);
@ -210,8 +205,8 @@ int sound_update(unsigned int cycles)
#endif
/* adjust PSG & FM cycle counts for next frame */
psg_cycles_count -= (cycles << 11);
fm_cycles_count -= (cycles << 11);
psg_cycles_count -= cycles;
fm_cycles_count -= cycles;
#ifdef LOGSOUND
error("%lu PSG cycles left\n",psg_cycles_count);
@ -224,7 +219,7 @@ int sound_update(unsigned int cycles)
/* Reset FM chip */
void fm_reset(unsigned int cycles)
{
fm_update(cycles);
fm_update(cycles << 11);
YM2612ResetChip();
}
@ -232,20 +227,20 @@ void fm_reset(unsigned int cycles)
void fm_write(unsigned int cycles, unsigned int address, unsigned int data)
{
if (address & 1)
fm_update(cycles);
fm_update(cycles << 11);
YM2612Write(address, data);
}
/* Read FM status */
unsigned int fm_read(unsigned int cycles, unsigned int address)
{
fm_update(cycles);
fm_update(cycles << 11);
return YM2612Read();
}
/* Write PSG chip */
void psg_write(unsigned int cycles, unsigned int data)
{
psg_update(cycles);
psg_update(cycles << 11);
SN76489_Write(data);
}