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* FIR フィルタの処理順序が反対になっているバグ修正
* FIR フィルタのオーバーフロー処理を修正
* エコーを使用しているチャンネルをすべてミュートしたとき、FIR 処理を停止するように修正
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@dgrfactory
dgrfactory committed Aug 28, 2023
1 parent fac2f5a commit cb58b97
Showing 1 changed file with 63 additions and 20 deletions.
83 changes: 63 additions & 20 deletions snesapu.dll/DSP.asm
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Original file line number Diff line number Diff line change
Expand Up @@ -262,7 +262,7 @@ SECTION .bss ALIGN=64
;Don't touch! All arrays are carefully aligned on large boundaries to facillitate easier indexing
;and better cache utilization.

; ----- degrade-factory code [2022/09/03] -----
; ----- degrade-factory code [2023/08/28] -----
;DSP Core ---------------------------- [0]
mix resb 1024 ;<VoiceMix> Mixing settings for each voice
dsp resb 128 ;<DSPRAM> DSP registers
Expand Down Expand Up @@ -422,11 +422,12 @@ SECTION .bss ALIGN=64
mixBuf resd MIX_SIZE*4 ;Temporary mixing buffer (linear buffer)
echoBuf resd ECHOBUF ;External echo memory, 240ms @ 192kHz (ring buffer)
firBuf resd FIRBUF ;Unaltered echo samples fed into FIR filter (ring buffer)
resw FIRBUF ; Triple buffer
lowBufL1 resd LOWBUF1 ;BASS-BOOST buffer (Left)
lowBufL2 resd LOWBUF2
lowBufR1 resd LOWBUF1 ;BASS-BOOST buffer (Right)
lowBufR2 resd LOWBUF2
; ----- degrade-factory code [END] #37 #45 #52 -----
; ----- degrade-factory code [END] #37 #45 #52 #61 -----

; ----- degrade-factory code [2015/07/11] -----
dspVarEP resd 1 ;Endpoint of DSP.asm variables
Expand Down Expand Up @@ -803,7 +804,7 @@ USES ECX,EDX,EBX,ESI,EDI
ENDP


; ----- degrade-factory code [2012/02/18] -----
; ----- degrade-factory code [2023/08/28] -----
;===================================================================================================
;Erase echo filter memory

Expand All @@ -817,11 +818,14 @@ PROC ResetEcho

Mov EDI,firBuf
Mov ECX,FIRBUF
Add ECX,FIRBUF/2
Rep StoSD

ENDP
; ----- degrade-factory code [END] #61 -----


; ----- degrade-factory code [2012/02/18] -----
;===================================================================================================
;Erase BASS-BOOST memory

Expand All @@ -845,8 +849,10 @@ PROC ResetLow
Rep StoSD

ENDP
; ----- degrade-factory code [END] -----


; ----- degrade-factory code [2012/02/18] -----
;===================================================================================================
;Reset master and echo volume

Expand Down Expand Up @@ -3734,6 +3740,43 @@ ENDP
; ----- degrade-factory code [END] #37 -----

%macro FIRFilter 0
; ----- degrade-factory code [2023/08/28] -----
Test dword [dspOpts],DSP_ECHOFIR
JZ short %%NoZero

Mov EBX,mix
XOr DX,DX
Inc DH
Mov CL,8

%%ChMute:
Test byte [EBX+mFlg],MFLG_MUTE ;Is voice muted by user?
SetZ AL
Dec AL
And AL,DH
Or DL,AL

Sub EBX,-80h
Add DH,DH

Dec CL
JNZ short %%ChMute

Test DL,DL ;DL = Muted channels, are any channels muted?
JZ short %%NoZero ; No

Not DL ;DL = Not muted channels
Mov DH,[dsp+eon] ;DH = Using echo channels
And DH,DL ;Are all channels using echoes muted?
JNZ short %%NoZero ; No
FLd dword [fpShR1] ;Force feedback in half, without echo. (If there is
FMul ST1,ST ; a loud feedback that causes clipping, mute the
FMul ST2,ST ; channel toprevent the sound from playing forever.)
FStP ST ;

%%NoZero:
; ----- degrade-factory code [END] #61 -----

Sub byte [firCur],4 ;Move index back one sample. (Index will wrap around
Mov EBX,[firCur] ; after 64 samples, enough for up to 256kHz output.)
LEA EBX,[EBX*2+firBuf] ;EBX -> Current sample in filter buffer
Expand All @@ -3753,15 +3796,18 @@ ENDP
; ----- degrade-factory code [END] #37 -----

FSt dword [EBX] ;Store new samples in buffer
FStP dword [FIRBUF*2+EBX] ; |FBR
FSt dword [FIRBUF*2+EBX]
FStP dword [FIRBUF*4+EBX] ; |FBR
FSt dword [4+EBX]
FStP dword [FIRBUF*2+4+EBX] ; |(empty)
FSt dword [FIRBUF*2+4+EBX]
FStP dword [FIRBUF*4+4+EBX] ; |(empty)

FLdZ ; |0
FLdZ ; |0 0
; ----- degrade-factory code [2021/10/31] -----
Mov EDX,firTaps+28 ;EDX -> Filter taps
; ----- degrade-factory code [END] #37 -----
; ----- degrade-factory code [2023/08/28] -----
Add EBX,FIRBUF*2+56 ;EBX -> Unfiltered sample
Mov EDX,firTaps ;EDX -> Filter taps
; ----- degrade-factory code [END] #37 #61 -----
Mov dword [ESP-8],0 ;Reset decimal overflow, so filtering is consistant
Mov CL,8 ;8-tap FIR filter

Expand All @@ -3782,8 +3828,8 @@ ENDP
FAddP ST2,ST ; |0 ((S1-S2)*FD+S2)*FT FD

; ----- degrade-factory code [2021/10/31] -----
ZeroDN 4+EBX
ZeroDN 12+EBX
ZeroDN 4+EBX
; ----- degrade-factory code [END] -----

FLd dword [12+EBX] ;Interpolate right sample |0 FBL FD S1
Expand All @@ -3793,14 +3839,11 @@ ENDP
FMul dword [EDX] ; |0 FBL ((S1-S2)*FD+S2)*FT
FAddP ST2,ST ; |FBR FBL

; ----- degrade-factory code [2021/11/27] -----
; ----- degrade-factory code [2023/08/28] -----
Test dword [dspOpts],DSP_ECHOFIR
JZ %%ClampH

Dec CL ;Is calculate the oldest sample (n=0)?
JZ short %%ClampL ; Yes
Test dword [EDX],-1 ;FIR coefficient is minus?
JS short %%ClampL ; Yes
FLd ST ;Cut high-order bits |FBR FBL FBL
FIRCut16 ST1
FStP ST ; |FBR FBL
Expand Down Expand Up @@ -3834,17 +3877,17 @@ ENDP
FStP ST ; |FBR FBL

%%Next:
; ----- degrade-factory code [END] #23 #37 -----
; ----- degrade-factory code [END] #23 #37 #61 -----

Mov EAX,[ESP-8] ;Determine next sample to use in filter
Add EAX,[firRate]
Mov [ESP-8],AX
ShR EAX,16

LEA EBX,[EAX*8+EBX] ;EBX -> Sample to use in filter
; ----- degrade-factory code [2021/10/31] -----
Sub EDX,4 ;EDX -> Next filter tap
; ----- degrade-factory code [END] #37 -----
; ----- degrade-factory code [2023/08/28] -----
ShL EAX,3 ;Multiply upper 16-bit by 8, not use 'ShR EAX,13'
Sub EBX,EAX ;EBX -> Sample to use in filter
Add EDX,4 ;EDX -> Next filter tap
; ----- degrade-factory code [END] #37 #61 -----

Dec CL
JNZ %%Tap
Expand Down Expand Up @@ -3998,7 +4041,7 @@ USES ALL
Mov ESI,mix+mFlg

.Noise:
Test byte [ESI],MFLG_NOISE ;Is channel muted?
Test byte [ESI],MFLG_NOISE ;Is noise enabled?
SetZ DL
Dec DL
And DL,BL
Expand Down

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