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SPU2-X: Improved dplII decoder algorithm, it now generates more defined positional balance. 

It's still most probably very wrong, but its sounding nice at least. ;P

git-svn-id: http://pcsx2.googlecode.com/svn/trunk@4860 96395faa-99c1-11dd-bbfe-3dabce05a288
This commit is contained in:
gigaherz 2011-08-10 20:59:40 +00:00
parent a4a40441c9
commit 08b2cac8aa
1 changed files with 34 additions and 44 deletions
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78
plugins/spu2-x/src/DplIIdecoder.cpp
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@ -22,9 +22,8 @@ static const u8 sLogTable[256] = {
static float Gfl=0,Gfr=0;
static float LMax=0,RMax=0;
static float LAccum=0;
static float RAccum=0;
static s32 ANum=0;
static float AccL=0;
static float AccR=0;
const float Scale = 4294967296.0f; // tweak this value to change the overall output volume
@ -46,61 +45,52 @@ extern void ResetDplIIDecoder()
Gfr=0;
LMax=0;
RMax=0;
LAccum=0;
RAccum=0;
ANum=0;
AccL=0;
AccR=0;
}
void ProcessDplIISample32( const StereoOut32& src, Stereo51Out32DplII * s)
{
float ValL = src.Left / (float)(1<<(SndOutVolumeShift+16));
float ValR = src.Right / (float)(1<<(SndOutVolumeShift+16));
float IL = src.Left / (float)(1<<(SndOutVolumeShift+16));
float IR = src.Right / (float)(1<<(SndOutVolumeShift+16));
float XL = abs(ValL);
float XR = abs(ValR);
// Calculate center channel and LFE
float C = (IL+IR) * 0.5f;
float SUB = C; // no need to lowpass, the speaker amplifier should take care of it
if(XL>LMax) LMax = XL; // 23
if(XR>RMax) RMax = XR;
float L = IL - C; // Effective L/R data
float R = IR - C;
ANum++;
if(ANum>=128)
{
ANum=0;
LAccum = (LAccum * 0.9f + LMax * 0.1f);
RAccum = (RAccum * 0.9f + RMax * 0.1f);
// Peak L/R
float PL = abs(L);
float PR = abs(R);
LMax = 0;
RMax = 0;
AccL += (PL-AccL)*0.1f;
AccR += (PR-AccR)*0.1f;
// Calculate power balance
float Balance = (AccR-AccL); // -1 .. 1
float Tfl=RAccum/std::max(1.0f,LAccum);
float Tfr=LAccum/std::max(1.0f,RAccum);
// If the power levels are different, then the audio is meant for the front speakers
float Frontness = abs(Balance);
float Rearness = 1-Frontness; // And the other way around
float gMax = std::max(1.0f,std::max(Tfl,Tfr));
Tfl = Tfl/gMax;
Tfr = Tfr/gMax;
// Equalize the power levels for L/R
float B = std::min(0.5f,std::max(-0.5f,Balance));
if(Tfl<0.00001f) Tfl=0.00001f;
if(Tfr<0.00001f) Tfr=0.00001f;
float VL = L / (1-B); // if B>0, it means R>L, so increase L, else decrease L
float VR = R / (1+B); // vice-versa
Gfl = Gfl * 0.78f + Tfl * 0.22f;
Gfr = Gfr * 0.78f + Tfr * 0.22f;
}
// 1.73+1.22 = 2.94; 2.94 = 0.34 = 0.9996; Close enough... xcept VL/VR are equalized to < 1
const float RearScale = 0.34f * 2;
float C = (ValL+ValR) * 0.5f;
float SL = (VR*1.73f - VL*1.22f) * RearScale * Rearness;
float SR = (VR*1.22f - VL*1.73f) * RearScale * Rearness;
// Possible experiment: Play with stereo expension levels on rear
float L = ValL - C;
float R = ValR - C;
float SUB = C;
float Cfl = (1+log(Gfl+1)/log(2.0f));
float Cfr = (1+log(Gfr+1)/log(2.0f));
float VL = L * Cfl;
float VR = R * Cfr;
float SL = (VR*1.73f - VL*1.22f)*0.25*Cfr; // not sure about this
float SR = (VR*1.22f - VL*1.73f)*0.25*Cfl;
// Adjust the volume of the front speakers based on what we calculated above
L *= Frontness;
R *= Frontness;
s32 CX = (s32)(C * AddCLR);