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sound, fix psg audio (missed commit)

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This commit is contained in:
kub 2021-09-25 08:27:32 +02:00
parent af01b1b16f
commit fa0c5b4539
1 changed files with 3 additions and 5 deletions
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8
pico/sound/sn76496.c
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@ -90,7 +90,6 @@ void SN76496Write(int data)
case 4: /* tone 2 : frequency */
R->Period[c] = R->UpdateStep * data;
if (R->Period[c] == 0) R->Period[c] = R->UpdateStep;
R->Count[c] = 0;
if (r == 4)
{
/* update noise shift frequency */
@ -109,8 +108,7 @@ void SN76496Write(int data)
R->NoiseFB = (n & 4) ? FB_WNOISE : FB_PNOISE;
n &= 3;
/* N/512,N/1024,N/2048,Tone #3 output */
R->Period[3] = (n == 3) ? 2 * R->Period[2] : (R->UpdateStep << (4 + n));
R->Count[3] = 0;
R->Period[3] = 2 * (n == 3 ? R->Period[2] : R->UpdateStep << (4 + n));
/* reset noise shifter */
R->RNG = FB_PNOISE;
@ -156,7 +154,7 @@ void SN76496Update(short *buffer, int length, int stereo)
/* If we exit the loop in the middle, Output[i] has to be inverted */
/* and vol[i] incremented only if the exit status of the square */
/* wave is 1. */
if (R->Count[i] < -2*R->Period[i]) {
if (R->Count[i] < -2*R->Period[i] || R->Volume[i] == 0) {
/* Cut of anything above the Nyquist freqency */
/* It will only create aliasing anyway */
vol[i] += STEP/2; // mean value
@ -200,7 +198,7 @@ void SN76496Update(short *buffer, int length, int stereo)
}
left -= nextevent;
} while (left > 0);
} while (left > 0 && R->Volume[3]);
if (R->Output[3]) vol[3] -= R->Count[3];
out = vol[0] * R->Volume[0] + vol[1] * R->Volume[1] +