RaySollium99/picodrive
1
0
Fork 0
mirror of https://github.com/RaySollium99/picodrive.git synced 2025-09-04 23:07:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Merge from libretro/master:46902e0 for repo synchronization

Browse source
This commit is contained in:
kub 2020-12-05 10:21:35 +01:00
parent 9d1ecde692
commit 61d76999d7
74 changed files with 14043 additions and 2094 deletions
Download patch file Download diff file Expand all files Collapse all files

80
pico/sound/sound.c
View file

@ -26,6 +26,73 @@ short cdda_out_buffer[2*1152];
// sn76496
extern int *sn76496_regs;
// Low pass filter 'previous' samples
static int32_t lpf_lp;
static int32_t lpf_rp;
static void low_pass_filter_stereo(int *buf32, int length)
{
int samples = length;
int *out32 = buf32;
// Restore previous samples
int32_t lpf_l = lpf_lp;
int32_t lpf_r = lpf_rp;
// Single-pole low-pass filter (6 dB/octave)
int32_t factor_a = PicoIn.sndFilterRange;
int32_t factor_b = 0x10000 - factor_a;
do
{
// Apply low-pass filter
lpf_l = (lpf_l * factor_a) + (out32[0] * factor_b);
lpf_r = (lpf_r * factor_a) + (out32[1] * factor_b);
// 16.16 fixed point
lpf_l >>= 16;
lpf_r >>= 16;
// Update sound buffer
*out32++ = lpf_l;
*out32++ = lpf_r;
}
while (--samples);
// Save last samples for next frame
lpf_lp = lpf_l;
lpf_rp = lpf_r;
}
static void low_pass_filter_mono(int *buf32, int length)
{
int samples = length;
int *out32 = buf32;
// Restore previous sample
int32_t lpf_l = lpf_lp;
// Single-pole low-pass filter (6 dB/octave)
int32_t factor_a = PicoIn.sndFilterRange;
int32_t factor_b = 0x10000 - factor_a;
do
{
// Apply low-pass filter
lpf_l = (lpf_l * factor_a) + (out32[0] * factor_b);
// 16.16 fixed point
lpf_l >>= 16;
// Update sound buffer
*out32++ = lpf_l;
}
while (--samples);
// Save last sample for next frame
lpf_lp = lpf_l;
}
void (*low_pass_filter)(int *buf32, int length) = low_pass_filter_stereo;
// ym2413
#define YM2413_CLK 3579545
OPLL old_opll;
@ -51,6 +118,11 @@ PICO_INTERNAL void PsndReset(void)
// PsndRerate calls YM2612Init, which also resets
PsndRerate(0);
timers_reset();
// Reset low pass filter
lpf_lp = 0;
lpf_rp = 0;
mix_reset();
}
@ -107,6 +179,9 @@ void PsndRerate(int preserve_state)
// set mixer
PsndMix_32_to_16l = (PicoIn.opt & POPT_EN_STEREO) ? mix_32_to_16l_stereo : mix_32_to_16_mono;
// set low pass filter
low_pass_filter = (PicoIn.opt & POPT_EN_STEREO) ? low_pass_filter_stereo : low_pass_filter_mono;
if (PicoIn.AHW & PAHW_PICO)
PicoReratePico();
}
@ -388,6 +463,11 @@ static int PsndRender(int offset, int length)
if ((PicoIn.AHW & PAHW_32X) && (PicoIn.opt & POPT_EN_PWM))
p32x_pwm_update(buf32, length-offset, stereo);
// Apply low pass filter, if required
if (PicoIn.sndFilter == 1) {
low_pass_filter(buf32, length);
}
// convert + limit to normal 16bit output
PsndMix_32_to_16l(PicoIn.sndOut+(offset<<stereo), buf32, length-offset);