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Initial assembler version of NTSC artifact code
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@IanSB
IanSB committed Mar 12, 2022
1 parent 04035a8 commit 3638619
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293 changes: 293 additions & 0 deletions src/capture_line_ntsc_8bpp.S
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Expand Up @@ -1353,9 +1353,301 @@ loop_8bppd_auto:
orr \reg, \reg, r9, lsl #(24 - (PIXEL_BASE + 6))
.endm

.macro SWAP reg0 reg1
eor \reg0, \reg0, \reg1
eor \reg1, \reg0, \reg1
eor \reg0, \reg0, \reg1
.endm

.global cga_process_artifact
.global cga_render_words
.global Composite_Process_Asm
.global CGA_Composite_Table
.global validate_cga
.global video_ri
.global video_rq
.global video_gi
.global video_gq
.global video_bi
.global video_bq

.macro DECODE_CGA phase bits //rgbi value enters in r0 //r12 now free
//mov r0, #0x02

ldmia r14, {r1-r9} //r1=old rgbi from last capture r2-r9 = 3 to -4
//and r1, #0x0f
sub r11, r14, #(pixelbuffer - CGA_Composite_Table)
mov r1, r1, lsl #(6 + 2) //6 shifted 2 because words not bytes
orr r1, r1, r0, lsl #(2 + 2) //2 shifted 2 because words not bytes
.if \phase != 0 //omit instruction if phase is 0
orr r1, r1, #(\phase << 2) //shifted by 2 as word not byte
.endif
ldr r1, [r11, r1] // read CGA_Composite_Table
// r1 - r5 now = i(2) to i(-2)

//r10 = ap[1] = (-i[-2]+((i[0])<<1)-i[2])<<1;
//r11 = bp[1] = (-i[-1]+i[1])<<2;

//r10 = ap[1] = (-r5+(r3<<1)-r1)<<1;
//r11 = bp[1] = (-r4+r2)<<2;
mov r10, r3, lsl #1
sub r10, r10, r1
// rsb r10, r1, r3, lsl #1
sub r11, r2, r4
sub r10, r10, r5
mov r11, r11, lsl #2
mov r10, r10, lsl #1
// r6 = adjusted i[0], r7 = adjusted i[-1]
mov r5, r2, lsl #3 //(i[1]<<3)
sub r5, r5, r10 //adjusted i[1] = (i[1]<<3) - ap[1]
// now r5 = adjusted i[1]
add r12, r7, r5 //r12 = Y = (adjusted) i[-1] +i[1]
mov r7, r10 //r7 = ap[1]

// r8 = ap[0], r9 = bp[0]

mov r10, r8 // r10 is now ap[0] r9 is now bp[0]
mov r8, r11 // r8 is now bp[1]

stmia r14, {r0-r8} //save last rgbi value (r0) plus yuv values (r1-r4) plus adjusted i[1] & i[0] values plus ap[1] & bp[1]

add r11, r14, #(video_ri - pixelbuffer)
ldmia r11, {r0-r5}

add r12, r12, r6, lsl #1 //r12 = Y = (adjusted) i[0]+i[0] + i[-1] +i[1] (c + d)
mov r12, r12, lsl #8 //r12 = c+d << 8

.if \phase == 1
rsb r9, r9, #0 //negate b(0)
SWAP r9 r10 //swap a(0) & b(0)
.elseif \phase == 2
rsb r10, r10, #0 //negate a(0)
rsb r9, r9, #0 //negate b(0)
.elseif \phase == 3
rsb r10, r10, #0 //negate a(0)
SWAP r9 r10 //swap a(0) & b(0)
.endif
mul r0, r0, r10 //video_ri*(a)
mul r1, r1, r9 //video_rq*(b)

mul r2, r2, r10 //video_gi*(a)
mul r3, r3, r9 //video_gq*(b)

add r0, r0, r1 //video_ri*(a) + video_rq*(b);
adds r0, r0, r12 //rr = y + video_ri*(a) + video_rq*(b);
// movs r0, r12
movmi r0, #0

.if \bits == 4
mov r0, r0, lsr #(13 + 4) //v >>= 13 but add 4 as 4 bit RGB
.else
mov r0, r0, lsr #13 //v >>= 13 for 8 bit RGB
.endif

mul r4, r4, r10 //video_bi*(a)
mul r5, r5, r9 //video_bq*(b)

add r1, r2, r3 //video_gi*(a) + video_gq*(b);
adds r1, r1, r12 //gg = y + video_gi*(a) + video_gq*(b);
// movs r1, r12
movmi r1, #0

.if \bits == 4
mov r1, r1, lsr #(13 + 4) //v >>= 13 but add 4 as 4 bit RGB
.else
mov r1, r1, lsr #13 //v >>= 13 for 8 bit RGB
.endif

add r2, r4, r5 //video_bi*(a) + video_bq*(b);
adds r2, r2, r12 //bb = y + video_bi*(a) + video_bq*(b);
// movs r2, r12
movmi r2, #0

.if \bits == 4
mov r2, r2, lsr #(13 + 4) //v >>= 13 but add 4 as 4 bit RGB
.else
mov r2, r2, lsr #13 //v >>= 13 for 8 bit RGB
.endif

.if \bits == 4
cmp r0, #0x10
movge r0, #0x0f
cmp r1, #0x10
movge r1, #0x0f
cmp r2, #0x10
movge r2, #0x0f
orr r2, r2, r1, lsl #4
orr r0, r2, r0, lsl #8
.else
cmp r0, #0x100
movge r0, #0xff
cmp r1, #0x100
movge r1, #0xff
cmp r2, #0x100
movge r2, #0xff
orr r2, r2, r1, lsl #8
orr r0, r2, r0, lsl #16
.endif

.endm


.align 6
Composite_Process_Asm:
push {r1-r12,lr}
//r0= cga_screen_blocks_copy
//r1= cga_rgbi_table
//r2= writeflag
str r0, saved_blocks
str r1, saved_table
str r2, saved_flag
Composite_Process_Asm_loop:
adrl r14, pixelbuffer
ldr r1, saved_table
ldr r0, [r1]
and r0, #0x0f
DECODE_CGA 0 4
str r0, decoded_pixel
ldr r1, saved_table
ldr r0, [r1]
mov r0, r0, lsr #8
and r0, #0x0f
DECODE_CGA 1 4
ldr r1, decoded_pixel
orr r1, r0, lsl #16
str r1, decoded_pixel

ldr r1, saved_table
ldr r0, [r1]
mov r0, r0, lsr #16
and r0, #0x0f
DECODE_CGA 2 4
str r0, decoded_pixel + 4
ldr r1, saved_table
ldr r0, [r1]
mov r0, r0, lsr #24
and r0, #0x0f
DECODE_CGA 3 4
ldr r1, decoded_pixel + 4
orr r1, r0, lsl #16
str r1, decoded_pixel + 4


ldr r1, saved_table
ldr r0, [r1, #4]
and r0, #0x0f
DECODE_CGA 0 4
str r0, decoded_pixel + 8
ldr r1, saved_table
ldr r0, [r1, #4]
mov r0, r0, lsr #8
and r0, #0x0f
DECODE_CGA 1 4
ldr r1, decoded_pixel + 8
orr r1, r0, lsl #16
str r1, decoded_pixel + 8

ldr r1, saved_table
ldr r0, [r1, #4]
mov r0, r0, lsr #16
and r0, #0x0f
DECODE_CGA 2 4
str r0, decoded_pixel + 12
ldr r1, saved_table
ldr r0, [r1, #4]
mov r0, r0, lsr #24
and r0, #0x0f
DECODE_CGA 3 4
ldr r1, decoded_pixel + 12
orr r1, r0, lsl #16
str r1, decoded_pixel + 12

ldr r2, saved_flag
cmp r2, #0
beq norendercga

adr r0, decoded_pixel
ldmia r0, {r5-r7, r10}

adrl r4, cga_screen_pointer_copy
ldmia r4, {r0-r3, r11, r12}

orr r5, r5, r11
orr r6, r6, r11
orr r7, r7, r11
orr r10, r10, r11

WRITE_R5_R6_R7_R10_16BPP
adrl r4, cga_screen_pointer_copy
str r0, [r4]
norendercga:
ldr r0, saved_table
add r0, r0, #8
str r0, saved_table
ldr r1, saved_blocks
subs r1, r1, #1
str r1, saved_blocks
bne Composite_Process_Asm_loop

pop {r1-r12, pc}

saved_blocks:
.word 0
saved_table:
.word 0
saved_flag:
.word 0
decoded_pixel:
.word 0
.word 0
.word 0
.word 0


.align 6
CGA_Composite_Table:
.space (4096)
.align 6
pixelbuffer:
.word 0 // 2 r1 (stored oldrgbi <<6 + new rgbi <<2) (when loaded contains stored old rgbi but after contains looked up YUV value)
.word 0 // 1 r2
.word 0 // 0 r3
.word 0 //-1 r4
.word 0 //-2 r5
i_buffer:
.word 0
.word 0
ap_buffer:
.word 0
.word 0
.align 6
decoded_pixels: //64 bit aligned
.word 0
.word 0
.word 0
.word 0

video_ri: //64 bit aligned
.word 0
video_rq:
.word 0
video_gi:
.word 0
video_gq:
.word 0
video_bi:
.word 0
video_bq:
.word 0

saved_regs:
.word 0
.word 0
.word 0
.word 0
.word 0



.align 6

Expand Down Expand Up @@ -1449,6 +1741,7 @@ cga_process_artifact: //called from core 1
adrl r1, cga_rgbi_table
mov r2, #1
bl Composite_Process //call reenigne's artifact code
//bl Composite_Process_Asm //in progress
pop {pc}

cga_render_words: //write 4 words of rgb data (eight 16 bit pixels) to the screen. (Called from reenigne's artifact code)
Expand Down
3 changes: 3 additions & 0 deletions src/vid_cga_comp.c
View file
Expand Up @@ -262,6 +262,9 @@ void Composite_Process(Bit32u blocks, Bit8u *rgbi, int render)
for (x = -1; x < w + 1; ++x) {
ap[x] = i[-4]-((i[-2]-i[0]+i[2])<<1)+i[4];
bp[x] = (i[-3]-i[-1]+i[1]-i[3])<<1;

// ap[x] = (-i[-2]+((i[0])<<1)-i[2])<<1;
// bp[x] = (-i[-1]+i[1])<<2;
++i;
}

Expand Down
5 changes: 3 additions & 2 deletions src/vid_cga_comp.h
View file
@@ -1,7 +1,8 @@
int CGA_Composite_Table[1024];
extern int CGA_Composite_Table[1024];
int video_sharpness;
int video_ri, video_rq, video_gi, video_gq, video_bi, video_bq;
extern int video_ri, video_rq, video_gi, video_gq, video_bi, video_bq;

void update_cga16_color();
void Composite_Process(Bit32u blocks, Bit8u *rgbi, int render);
void Test_Composite_Process(Bit32u blocks, Bit8u *rgbi, int render);
extern void Composite_Process_Asm(Bit32u blocks, Bit8u *rgbi, int render);

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