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AICA updates [Deunan Knute, ajax16384, R. Belmont]

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- Fixed ADPCM decoder to remove bad optimization and match YMZ280B.  DC offset is fixed and output quality is higher
- Improved handling of slot monitor and timers B and C
- Simplified interpolation code
This commit is contained in:
R. Belmont 2008-07-28 05:46:29 +00:00
parent 867d51a2bc
commit 67faaeb473
1 changed files with 20 additions and 46 deletions
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66
src/emu/sound/aica.c
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@ -123,12 +123,10 @@ struct _SLOT
struct _LFO ALFO; //Amplitude LFO
int slot;
int cur_sample; //current ADPCM sample
int nxt_sample; //next ADPCM sample
int cur_quant; //current ADPCM step
int nxt_quant; //next ADPCM step
int curstep, nxtstep;
int curstep;
int cur_lpquant, cur_lpsample, cur_lpstep;
UINT8 *adbase, *nxtbase, *adlpbase;
UINT8 *adbase, *adlpbase;
UINT8 mslc; // monitored?
};
@ -442,10 +440,11 @@ static void InitADPCM(int *PrevSignal, int *PrevQuant)
*PrevQuant=0x7f;
}
INLINE signed short DecodeADPCM(int *PrevSignal, unsigned char Delta, int *PrevQuant)
INLINE signed short inline DecodeADPCM(int *PrevSignal, unsigned char Delta, int *PrevQuant)
{
*PrevSignal+=(*PrevQuant*quant_mul[Delta&15])>>(3);
*PrevSignal=ICLIP16(*PrevSignal);
int x = *PrevQuant * quant_mul [Delta & 15];
x = *PrevSignal + ((int)(x + ((UINT32)x >> 29)) >> 3);
*PrevSignal=ICLIP16(x);
*PrevQuant=(*PrevQuant*TableQuant[Delta&7])>>ADPCMSHIFT;
*PrevQuant=(*PrevQuant<0x7f)?0x7f:((*PrevQuant>0x6000)?0x6000:*PrevQuant);
return *PrevSignal;
@ -471,10 +470,9 @@ static void AICA_StartSlot(struct _AICA *AICA, struct _SLOT *slot)
UINT8 *base;
UINT32 curstep, steps_to_go;
slot->curstep = slot->nxtstep = 0;
slot->adbase = slot->nxtbase = (unsigned char *) (AICA->AICARAM+((SA(slot))&0x7fffff));
slot->curstep = 0;
slot->adbase = (unsigned char *) (AICA->AICARAM+((SA(slot))&0x7fffff));
InitADPCM(&(slot->cur_sample), &(slot->cur_quant));
InitADPCM(&(slot->nxt_sample), &(slot->nxt_quant));
InitADPCM(&(slot->cur_lpsample), &(slot->cur_lpquant));
// walk to the ADPCM state at LSA
@ -1085,12 +1083,16 @@ INLINE INT32 AICA_UpdateSlot(struct _AICA *AICA, struct _SLOT *slot)
{
UINT8 *base= slot->adbase;
INT32 s;
int cur_sample; //current ADPCM sample
int nxt_sample; //next ADPCM sample
INT32 fpart=slot->cur_addr&((1<<SHIFT)-1);
UINT32 steps_to_go = addr1, curstep = slot->curstep;
UINT32 steps_to_go = addr2, curstep = slot->curstep;
if (slot->adbase)
{
// seek to the current sample
cur_sample = slot->cur_sample; // may already contains current decoded sample
// seek to the interpolation sample
while (curstep < steps_to_go)
{
int shift1, delta1;
@ -1102,33 +1104,15 @@ INLINE INT32 AICA_UpdateSlot(struct _AICA *AICA, struct _SLOT *slot)
{
base++;
}
if (curstep == addr1)
cur_sample = slot->cur_sample;
}
nxt_sample = slot->cur_sample;
slot->adbase = base;
slot->curstep = curstep;
base = slot->nxtbase;
curstep = slot->nxtstep;
steps_to_go = addr2;
// seek to the interpolation sample
while (curstep < steps_to_go)
{
int shift1, delta1;
shift1 = 4*((curstep&1));
delta1 = (*base>>shift1)&0xf;
DecodeADPCM(&(slot->nxt_sample),delta1,&(slot->nxt_quant));
curstep++;
if (!(curstep & 1))
{
base++;
}
}
slot->nxtbase = base;
slot->nxtstep = curstep;
s=(int) slot->cur_sample*((1<<SHIFT)-fpart)+(int) slot->nxt_sample*fpart;
s=(int)cur_sample*((1<<SHIFT)-fpart)+(int)nxt_sample*fpart;
}
else
{
@ -1171,7 +1155,7 @@ INLINE INT32 AICA_UpdateSlot(struct _AICA *AICA, struct _SLOT *slot)
rem_addr = *slot_addr[addr_select] - (LEA(slot)<<SHIFT);
*slot_addr[addr_select]=(LSA(slot)<<SHIFT) + rem_addr;
if(PCMS(slot)>=2 && addr_select==0)
if(PCMS(slot)>=2)
{
// restore the state @ LSA - the sampler will naturally walk to (LSA + remainder)
slot->adbase = &AICA->AICARAM[SA(slot)+(LSA(slot)/2)];
@ -1184,16 +1168,6 @@ INLINE INT32 AICA_UpdateSlot(struct _AICA *AICA, struct _SLOT *slot)
// printf("Looping: slot_addr %x LSA %x LEA %x step %x base %x\n", *slot_addr[addr_select]>>SHIFT, LSA(slot), LEA(slot), slot->curstep, slot->adbase);
}
else if(PCMS(slot)>=2 && addr_select==1)
{
slot->nxtbase = &AICA->AICARAM[SA(slot)+(LSA(slot)/2)];
slot->nxtstep = LSA(slot);
if (PCMS(slot) == 2)
{
slot->nxt_sample = slot->cur_lpsample;
slot->nxt_quant = slot->cur_lpquant;
}
}
}
break;
}
@ -1212,7 +1186,7 @@ INLINE INT32 AICA_UpdateSlot(struct _AICA *AICA, struct _SLOT *slot)
if(slot->mslc)
{
AICA->udata.data[0x12/2] = addr1;
AICA->udata.data[0x14/2] = addr1;
if (!(AFSEL(AICA)))
{
AICA->udata.data[0x10/2] |= slot->EG.state<<13;