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Update mixer volume calculations for the SBPRO1,2 and SB16. Thanks for the measurements James-F.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@4022
This commit is contained in:
Peter Veenstra 2017-06-08 17:32:17 +00:00
parent 6cf39c1fc6
commit 085c7a2f18
1 changed files with 24 additions and 12 deletions
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36
src/hardware/sblaster.cpp
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@ -1098,21 +1098,33 @@ static Bit8u DSP_ReadData(void) {
return sb.dsp.out.lastval;
}
//The soundblaster manual says 2.0 Db steps but we'll go for a bit less
#define CALCVOL(_VAL) (float)pow(10.0f,((float)(31-_VAL)*-1.3f)/20)
static float calc_vol(Bit8u amount) {
Bit8u count = 31 - amount;
float db = static_cast<float>(count);
if (sb.type == SBT_PRO1 || sb.type == SBT_PRO2) {
if (count) {
if (count < 16) db -= 1.0f;
else if (count > 16) db += 1.0f;
if (count == 24) db += 2.0f;
if (count > 27) return 0.0f; //turn it off.
}
} else { //Give the rest, the SB16 scale, as we don't have data.
db *= 2.0f;
if (count > 20) db -= 1.0f;
}
return (float) pow (10.0f,-0.05f * db);
}
static void CTMIXER_UpdateVolumes(void) {
if (!sb.mixer.enabled) return;
MixerChannel * chan;
//adjust to get linear master volume slider in trackers
chan=MIXER_FindChannel("SB");
if (chan) chan->SetVolume(float(sb.mixer.master[0])/31.0f*CALCVOL(sb.mixer.dac[0]),
float(sb.mixer.master[1])/31.0f*CALCVOL(sb.mixer.dac[1]));
chan=MIXER_FindChannel("FM");
if (chan) chan->SetVolume(float(sb.mixer.master[0])/31.0f*CALCVOL(sb.mixer.fm[0]),
float(sb.mixer.master[1])/31.0f*CALCVOL(sb.mixer.fm[1]));
chan=MIXER_FindChannel("CDAUDIO");
if (chan) chan->SetVolume(float(sb.mixer.master[0])/31.0f*CALCVOL(sb.mixer.cda[0]),
float(sb.mixer.master[1])/31.0f*CALCVOL(sb.mixer.cda[1]));
float m0 = calc_vol(sb.mixer.master[0]);
float m1 = calc_vol(sb.mixer.master[1]);
chan = MIXER_FindChannel("SB");
if (chan) chan->SetVolume(m0 * calc_vol(sb.mixer.dac[0]), m1 * calc_vol(sb.mixer.dac[1]));
chan = MIXER_FindChannel("FM");
if (chan) chan->SetVolume(m0 * calc_vol(sb.mixer.fm[0]) , m1 * calc_vol(sb.mixer.fm[1]) );
chan = MIXER_FindChannel("CDAUDIO");
if (chan) chan->SetVolume(m0 * calc_vol(sb.mixer.cda[0]), m1 * calc_vol(sb.mixer.cda[1]));
}
static void CTMIXER_Reset(void) {