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ESS register 0xA2 update function

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This commit is contained in:
Cacodemon345
2024-03-02 17:36:55 +06:00
committed by Kagamiin~
parent 3f72c788bd
commit 4369284f65
1 changed files with 15 additions and 0 deletions
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15
src/sound/snd_sb_dsp.c
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@@ -585,6 +585,18 @@ sb_dsp_setdma16_translate(sb_dsp_t *dsp, int translate)
dsp->sb_16_dma_translate = translate;
}
/* TODO: Investigate ESS cards' filtering on real hardware as well.
(DOSBox-X did it purely off some laptop's ESS chip, which isn't a good look.) */
static void sb_ess_update_filter_freq(sb_dsp_t *dsp) {
if (dsp->sb_freq >= 22050)
ESSreg(0xA1) = 256 - (795500UL / dsp->sb_freq);
else
ESSreg(0xA1) = 128 - (397700UL / dsp->sb_freq);
unsigned int freq = ((dsp->sb_freq * 4) / (5 * 2)); /* 80% of 1/2 the sample rate */
ESSreg(0xA2) = 256 - (7160000 / (freq * 82));
}
void
sb_exec_command(sb_dsp_t *dsp)
{
@@ -796,6 +808,9 @@ sb_exec_command(sb_dsp_t *dsp)
if ((dsp->sb_freq != temp) && (dsp->sb_type >= SB16))
recalc_sb16_filter(0, temp);
dsp->sb_freq = temp;
if (IS_ESS(dsp)) {
sb_ess_update_filter_freq(dsp);
}
break;
case 0x41: /* Set output sampling rate */
case 0x42: /* Set input sampling rate */