psx - fix some bad-sounding sounds bugs caused by some accidental older mednafen code

psx/octoshock/psx/spu.cpp

@@ -82,11 +82,6 @@ static const int16 FIR_Table[256][4] =
  #include "spu_fir_table.inc"
 };
 
-static const uint32 NoiseFreqTable[64] =
-{
- #include "spu_nft.inc"
-};
-
 PS_SPU::PS_SPU()
 {
  last_rate = -1;
@@ -94,8 +89,6 @@ PS_SPU::PS_SPU()
 
  IntermediateBufferPos = 0;
  memset(IntermediateBuffer, 0, sizeof(IntermediateBuffer));
-
- for(int16 a = 32760; a >= 0; a++);
 }
 
 PS_SPU::~PS_SPU()
@@ -147,6 +140,7 @@ void PS_SPU::Power(void)
  GlobalSweep[0].Power();
  GlobalSweep[1].Power();
 
+ NoiseDivider = 0;
  NoiseCounter = 0;
  LFSR = 0;
 
@@ -356,8 +350,6 @@ void PS_SPU::RunDecoder(SPU_Voice *voice)
 
  //for(int z = 0; z < 4; z++)
  {
-  const uint16 CV = SPURAM[voice->CurAddr];
-
   if(SPUControl & 0x40)
   {
    unsigned test_addr = voice->CurAddr & 0x3FFFF;
@@ -371,6 +363,8 @@ void PS_SPU::RunDecoder(SPU_Voice *voice)
 
   if((voice->CurAddr & 0x7) == 0)
   {
+   const uint16 CV = SPURAM[voice->CurAddr];
+
    voice->DecodeShift = CV & 0xF;
    voice->DecodeWeight = (CV >> 4) & 0xF;
    voice->DecodeFlags = (CV >> 8) & 0xFF;
@@ -389,9 +383,15 @@ void PS_SPU::RunDecoder(SPU_Voice *voice)
      }
     }
    }
+   voice->CurAddr = (voice->CurAddr + 1) & 0x3FFFF;
   }
-  else
+
+  //
+  // Don't else this block; we need to ALWAYS decode 4 samples per call to RunDecoder() if DecodeAvail < 11, or else sample playback
+  // at higher rates will fail horribly.
+  //
   {
+   const uint16 CV = SPURAM[voice->CurAddr];
    const unsigned shift = voice->DecodeShift;
    const int32 weight_m1 = Weights[voice->DecodeWeight][0];
    const int32 weight_m2 = Weights[voice->DecodeWeight][1];
@@ -414,8 +414,8 @@ void PS_SPU::RunDecoder(SPU_Voice *voice)
    }
    voice->DecodeWritePos = (voice->DecodeWritePos + 4) & 0x1F;
    voice->DecodeAvail += 4;
+   voice->CurAddr = (voice->CurAddr + 1) & 0x3FFFF;
   }
-  voice->CurAddr = (voice->CurAddr + 1) & 0x3FFFF;
  }
 }
 
@@ -477,9 +477,7 @@ void PS_SPU::RunEnvelope(SPU_Voice *voice)
  //static INLINE void CalcVCDelta(const uint8 zs, uint8 speed, bool log_mode, bool decrement, bool inv_increment, int16 Current, int &increment, int &divinco)
  switch(ADSR->Phase)
  {
-  default: assert(0);
-	   break;
-
+  default:	// Won't happen, but helps shut up gcc warnings.
   case ADSR_ATTACK:
 	CalcVCDelta(0x7F, ADSR->AttackRate, ADSR->AttackExp, false, false, (int16)ADSR->EnvLevel, increment, divinco);
 	uoflow_reset = 0x7FFF;
@@ -553,6 +551,32 @@ INLINE uint16 PS_SPU::ReadSPURAM(uint32 addr)
 
 #include "spu_reverb.inc"
 
+INLINE void PS_SPU::RunNoise(void)
+{
+ const unsigned rf = ((SPUControl >> 8) & 0x3F);
+ uint32 NoiseDividerInc = (2 << (rf >> 2));
+ uint32 NoiseCounterInc = 4 + (rf & 0x3);
+
+ if(rf >= 0x3C)
+ {
+  NoiseDividerInc = 0x8000;
+  NoiseCounterInc = 8;
+ }
+
+ NoiseDivider += NoiseDividerInc;
+ if(NoiseDivider & 0x8000)
+ {
+  NoiseDivider = 0;
+
+  NoiseCounter += NoiseCounterInc;
+  if(NoiseCounter & 0x8)
+  {
+   NoiseCounter &= 0x7;
+   LFSR = (LFSR << 1) | (((LFSR >> 15) ^ (LFSR >> 12) ^ (LFSR >> 11) ^ (LFSR >> 10) ^ 1) & 1);
+  }
+ }
+}
+
 int32 PS_SPU::UpdateFromCDC(int32 clocks)
 //pscpu_timestamp_t PS_SPU::Update(const pscpu_timestamp_t timestamp)
 {
@@ -793,12 +817,7 @@ int32 PS_SPU::UpdateFromCDC(int32 clocks)
 
   CWA = (CWA + 1) & 0x1FF;
 
-  NoiseCounter += NoiseFreqTable[(SPUControl >> 8) & 0x3F];
-  if(NoiseCounter >= 0x8000)
-  {
-   NoiseCounter -= 0x8000;
-   LFSR = (LFSR << 1) | (((LFSR >> 15) ^ (LFSR >> 12) ^ (LFSR >> 11) ^ (LFSR >> 10) ^ 1) & 1);
-  }
+  RunNoise();
 
   clamp(&accum_l, -32768, 32767);
   clamp(&accum_r, -32768, 32767);

psx/octoshock/psx/spu.h

@@ -133,10 +133,12 @@ private:
 
 
  void RunReverb(int32 in_l, int32 in_r, int32 &out_l, int32 &out_r);
+ void RunNoise(void);
  bool GetCDAudio(int32 &l, int32 &r);
 
  SPU_Voice Voices[24];
 
+ uint32 NoiseDivider;
  uint32 NoiseCounter;
  uint16 LFSR;
 

psx/octoshock/psx/spu_nft.inc

@@ -1,64 +0,0 @@
-0x00000001,
-0x00000001,
-0x00000001,
-0x00000001,
-0x00000002,
-0x00000002,
-0x00000002,
-0x00000002,
-0x00000004,
-0x00000005,
-0x00000006,
-0x00000007,
-0x00000008,
-0x0000000a,
-0x0000000c,
-0x0000000e,
-0x00000010,
-0x00000014,
-0x00000018,
-0x0000001c,
-0x00000020,
-0x00000028,
-0x00000030,
-0x00000038,
-0x00000040,
-0x00000050,
-0x00000060,
-0x00000070,
-0x00000080,
-0x000000a0,
-0x000000c0,
-0x000000e0,
-0x00000100,
-0x00000140,
-0x00000180,
-0x000001c0,
-0x00000200,
-0x00000280,
-0x00000300,
-0x00000380,
-0x00000400,
-0x00000500,
-0x00000600,
-0x00000700,
-0x00000800,
-0x00000a00,
-0x00000c00,
-0x00000e00,
-0x00001000,
-0x00001400,
-0x00001800,
-0x00001c00,
-0x00002000,
-0x00002800,
-0x00003000,
-0x00003800,
-0x00004000,
-0x00005000,
-0x00006000,
-0x00007000,
-0x00008000,
-0x00008000,
-0x00008000,
-0x00008000,