Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-23 00:39:36 +03:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

aica: add ADPCM diff value clamp based on encoder research [kode54, MetalliC]

Browse Source 
if there is known issues with YMZ280B it might be worth try to same decoder there
This commit is contained in:
MetalliC 2016-08-19 18:49:11 +03:00
parent 53962aff61
commit 3a6e75ca7d
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/devices/sound/aica.cpp
View File

@ -351,8 +351,14 @@ void aica_device::InitADPCM(int *PrevSignal, int *PrevQuant)
signed short aica_device::DecodeADPCM(int *PrevSignal, unsigned char Delta, int *PrevQuant)
{
int x = (*PrevQuant * quant_mul[Delta & 7]) / 8;
if (x > 0x7FFF) x = 0x7FFF;
if (Delta & 8) x = -x;
x += *PrevSignal;
#if 0 // older implementation
int x = *PrevQuant * quant_mul [Delta & 15];
x = *PrevSignal + ((int)(x + ((UINT32)x >> 29)) >> 3);
#endif
*PrevSignal=ICLIP16(x);
*PrevQuant=(*PrevQuant*TableQuant[Delta&7])>>ADPCMSHIFT;
*PrevQuant=(*PrevQuant<0x7f)?0x7f:((*PrevQuant>0x6000)?0x6000:*PrevQuant);