kolibrios/programs/media/zsea/plugins/png/cnv_png.asm

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;*****************************************************************************
; PNG to RAW convert plugin - for zSea image viewer
; Copyright (c) 2008-2011, Marat Zakiyanov aka Mario79, aka Mario
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are met:
; * Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
; * Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
; * Neither the name of the <organization> nor the
; names of its contributors may be used to endorse or promote products
; derived from this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY Marat Zakiyanov ''AS IS'' AND ANY
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
; DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;*****************************************************************************
format MS COFF
public EXPORTS
section '.flat' code readable align 16
;include 'macros.inc'
include '../../../../macros.inc'
;---------------------------------------------------------------------
START:
pushad
mov eax,dword [esp+36]
call check_header_1
je header_OK
;---------------------------------------------------------------------
no_png_file:
xor eax,eax
mov [raw_area],eax
inc eax ; data corrupt eax = 1
jmp header_OK.ret
;---------------------------------------------------------------------
check_header_1:
mov [pointer],eax
mov ebx,[eax]
mov [image_file],ebx
cmp [ebx],dword 0x474E5089 ; check main label p.1
jne @f ;no_png_file
cmp [ebx+4],dword 0x0A1A0A0D ; check main label p.2
ret
@@:
add esp,4
jmp no_png_file
;---------------------------------------------------------------------
header_OK:
mov ebx,[eax+12] ; file size
mov [file_size],ebx
;---------------------------------------------------------------------
mov ebx,[eax+16]
mov [deflate_unpack],ebx
;---------------------------------------------------------------------
mov ebx,[pointer]
;---------------------------------------------------------------------
xor eax,eax
; mov [IDAT.pointer],eax
; mov [IDAT.size],eax
mov [deflate_start_offset],eax
mov eax,[image_file]
mov [next_Chunk],eax
call search_IHDR
call search_IDAT
; call search_IEND
;---------------------------------------------------------------------
mov eax,[IHDR.pointer]
mov ecx,[eax] ; get width PNG
call convert_NBO_to_PC
mov [IHDR_data.Width],ecx ; store width PNG
mov [Image_Width],ecx
mov ecx,[eax+4] ; get height PNG
call convert_NBO_to_PC
mov [IHDR_data.Height],ecx ; store height PNG
mov [Image_Height],ecx
mov ecx,[eax+9] ; Color type
; Compression method
; Filter method
; Interlace method
mov [IHDR_data.Color_type],ecx
xor ecx,ecx
mov cl,[eax+8] ; Bit depth
mov [IHDR_data.Bit_depth],cl
;---------------------------------------------------------------------
mov al,[eax+9] ; check Color type
cmp al,byte 0 ; Each pixel is a grayscale sample.
je .resolution
cmp al,byte 2 ; Each pixel is an R,G,B triple.
je .Bit_depth_2
cmp al,byte 3 ; Each pixel is a palette index
; a PLTE chunk must appear.
jne .no_PLTE
call search_PLTE
jmp .resolution
.no_PLTE:
cmp al,byte 4 ; Each pixel is a grayscale sample,
; followed by an alpha sample.
je .Bit_depth_4
cmp al,byte 6 ; Each pixel is an R,G,B triple,
; followed by an alpha sample.
jne no_png_file
;---------------------------------------------------------------------
.Bit_depth_6:
shl ecx,1
.Bit_depth_4:
shl ecx,1
jmp .resolution
.Bit_depth_2:
lea ecx,[ecx*3]
.resolution:
;---------------------------------------------------------------------
cmp [IHDR_data.Compression_method], byte 0 ; check Compression method
jne no_png_file
cmp [IHDR_data.Filter_method], byte 0 ; check Filtering method
jne no_png_file
cmp [IHDR_data.Interlace_method], byte 0 ; No Interlaced
je @f
cmp [IHDR_data.Interlace_method], byte 1 ; Interlaced
jne no_png_file
@@:
;---------------------------------------------------------------------
mov [resolution],ecx
imul ecx,[IHDR_data.Width]
mov edi,ecx
shr ecx,3
test edi,7
jz @f
inc ecx
@@:
imul ecx,[IHDR_data.Height]
cmp [IHDR_data.Color_type],byte 3
jne @f
mov eax,[PLTE.size]
mov ebx,3
xor edx,edx
div ebx
shl eax,2
add ecx,eax ; PLTE table area
jmp .RAW_header
;--------------------------------------
@@:
cmp [IHDR_data.Color_type],byte 0
je @f
cmp [IHDR_data.Color_type],byte 4
jne .RAW_header
@@:
push ecx
mov eax,1
movzx ecx,byte [IHDR_data.Bit_depth]
cmp ecx,16
jne @f
shr ecx,1
@@:
shl eax,cl
shl eax,2
pop ecx
add ecx,eax
; mov ebx,[pointer]
; mov [ebx+20],eax
;--------------------------------------
.RAW_header:
add ecx,44 ; RAW header
; mov ebx,[pointer]
; mov [ebx+24],ecx
; shl ecx,1
mcall 68, 12
cmp eax,0
jne @f
xor eax,eax
mov [raw_area],eax ; store pointer of image area
mov eax,2 ; not enough memory
jmp .ret
@@:
mov [raw_area],eax
; mov ebx,[pointer]
; mov [ebx+28],eax
;---------------------------------------------------------------------
mov edi,eax
xor eax,eax
shr ecx,2
cld
rep stosd ; clear memory
;---------------------------------------------------------------------
; Create RAW header
;---------------------------------------------------------------------
mov eax,[raw_area]
mov [eax],dword 'RAW '
;---------------------------------------------------------------------
mov ecx,[IHDR_data.Width] ; width BMP
mov [eax+4],ecx ; width RAW
;---------------------------------------------------------------------
mov ecx,[IHDR_data.Height] ; high BMP
mov [eax+8],ecx ;high RAW
;---------------------------------------------------------------------
mov ecx,[resolution] ; color resolution BMP
mov [eax+12],ecx ;color resolution RAW
;---------------------------------------------------------------------
xor ecx,ecx
mov cl,[IHDR_data.Bit_depth]
mov [eax+16],cx ;channel color resolution RAW
;---------------------------------------------------------------------
mov ecx,[IHDR_data.Color_type]
xor ebx,ebx
inc ebx
cmp cl,byte 0 ; Each pixel is a grayscale sample.
je .1
cmp cl,byte 2 ; Each pixel is an R,G,B triple.
je .Bit_depth_2_1
cmp cl,byte 3 ; Each pixel is a palette index
; a PLTE chunk must appear.
je .1
cmp cl,byte 4 ; Each pixel is a grayscale sample,
; followed by an alpha sample.
je .Bit_depth_4_1
cmp cl,byte 6
jne no_png_file
.Bit_depth_6_1:
shl ebx,1
.Bit_depth_4_1:
shl ebx,1
jmp .1
.Bit_depth_2_1:
lea ebx,[ebx*3]
.1:
mov [eax+18],bx ; channels amount RAW
;---------------------------------------------------------------------
xor edx,edx
cmp cl,byte 3 ; Each pixel is a palette index
; a PLTE chunk must appear.
je @f
cmp cl,0
je @f
cmp cl,4
jne .no_PLTE_1
@@:
add edx,44
mov [eax+20],edx ; palette pointer (offset from file start)
;---------------------------------------------------------------------
cmp cl,0
je @f
cmp cl,4
jne .PLTE
@@:
mov ecx,256*4
jmp .PLTE_1
.PLTE:
push eax
mov eax,[PLTE.size]
xor edx,edx
mov ebx,3
div ebx
shl eax,2
mov ecx,eax
pop eax
.PLTE_1:
mov [eax+24],ecx ; palette area size
jmp @f
.no_PLTE_1:
xor ecx,ecx
@@:
;---------------------------------------------------------------------
add ecx,dword 44
mov [eax+28],ecx ; pixels pointer (offset from file start)
; mov ebx,[pointer]
; mov [ebx+44],ecx
;---------------------------------------------------------------------
mov ecx, [IHDR_data.Width] ; width BMP
imul ecx,[resolution]
mov edi,ecx
shr ecx,3
test edi,7
jz @f
inc ecx
@@:
imul ecx,[IHDR_data.Height] ; high BMP
mov [eax+32],ecx ; pixels area size
;---------------------------------------------------------------------
xor ecx,ecx ; Stub!!!
mov [eax+36],ecx ;Transparency pointer (offset from file start)
mov [eax+40],ecx ;Transparency area size
;---------------------------------------------------------------------
; Finish create RAW header
;---------------------------------------------------------------------
mov eax,[raw_area]
mov edi,[eax+20] ; palette pointer (offset from file start)
add edi,eax
mov esi,[PLTE.pointer]
mov eax,[PLTE.size]
xor edx,edx
mov ebx,3
div ebx
mov ecx,eax
mov eax,[IHDR_data.Color_type]
cmp al,byte 0
je .grayscale_palette
cmp al,byte 4
je .grayscale_palette
cmp al,byte 3 ; Each pixel is a palette index
; a PLTE chunk must appear.
jne .no_palette
@@:
cld
lodsd
dec esi
and eax,0xffffff
mov bl,al
shr eax,8
xchg ah,bl
shl eax,8
mov al,bl
cld
stosd
dec ecx
jnz @r
jmp .no_palette
;-------------------------------
.grayscale_palette:
; cmp [IHDR_data.Bit_depth], dword 1
; jne @f
; xor eax,eax
; cld
; stosd
; dec eax
; and eax,0xffffff
; cld
; stosd
; jmp .no_palette
@@:
mov eax,1
mov ecx,[resolution]
cmp ecx,8
jbe @f
mov ecx,8
@@:
shl eax,cl
mov ecx,eax
mov eax,256
; mov ebx,[resolution]
xor edx,edx
div ecx ;ebx
mov edx,eax
cmp edx,0
jne @f
inc edx
@@:
xor eax,eax
; mov eax,0xffffff
; mov ecx,256
@@:
cld
stosd
; inc ah
add ah,dl
; inc al
add al,dl
shl eax,8
mov al,ah
; dec ah
; dec al
; shl eax,8
; mov al,ah
and eax,0xffffff
dec ecx
jnz @r
sub edi,4
xor eax,eax
dec eax
and eax,0xffffff
cld
stosd
;-------------------------------
.no_palette:
;---------------------------------------------------------------------
mov ebx,[IDAT.pointer]
mov al,[ebx]
mov [IDAT_CMF],al ; Compression Method and flags
mov ah,al
and al,1111b
mov [IDAT_<EFBFBD><EFBFBD>],al ; Compression method
shr ah,4
mov [IDAT_CINFO],ah ; Compression info
mov al,[ebx+1]
mov [IDAT_FLG],al ; FLaGs
mov ah,al
and al,11111b
mov [IDAT_FCHECK],al
mov al,ah
and al,100000b
shr al,5
mov [IDAT_FDICT],al ; Preset dictionary
shr ah,6
mov [IDAT_FLEVEL],ah ; Compression level
mov al,[IDAT_<EFBFBD><EFBFBD>]
; test al,1000b ; Compression method = 8 ?
cmp al,8
jnz no_png_file
add [IDAT.pointer],2
sub [IDAT.size],2
; xor eax,eax
; mov ah,[IDAT_FLG]
; mov al,[IDAT_CMF]
; imul eax,31
; shr eax,16
; cmp [IDAT_FCHECK],al
; jne no_png_file
;
; cmp [IDAT_FDICT],1
; jne .no_IDAT_FDICT
; mov ecx,[ebx+2]
; jmp .IDAT_DICT
;.no_IDAT_FDICT:
; mov eax,[IDAT.pointer]
; add eax,[IDAT.size]
; mov ecx,[eax]
;.IDAT_DICT:
; call convert_NBO_to_PC
; mov [IDAT_DICT],ecx
; jmp .ret_ok
; jmp no_png_file
; mov ecx,[file_size]
; mcall 68, 12
; mov [IDAT_raw_area],eax ; store pointer of image area
;---------------------------------------------------------------------
.start_Deflate_unpack:
push eax ; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> *pUnpackedLength
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> push <<3C><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>>
push esp ; <20> <20><><EFBFBD> <20> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> pUnpackedLength
push esi ; <20><><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
push deflate_callback
call [deflate_unpack]
pop ecx ; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> UnpackedLength
; <20><><EFBFBD> <20> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, eax = <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, ecx = <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
mov [unpacked_data],eax
mov esi,eax
;---------------------------------------------------------------------
mov eax,[raw_area]
mov edi,[eax+28] ; pixels pointer (offset from file start)
add edi,eax
; mov ecx,edx
sub ecx,[IHDR_data.Height]
mov [first_line],byte 1
cmp [IHDR_data.Color_type],byte 0
je .PLTE_and_grayscale
cmp [IHDR_data.Color_type],byte 3
je .PLTE_and_grayscale
cmp [IHDR_data.Color_type],byte 4
je .PLTE_and_grayscale
;---------------------------------------------------------------------
; Processing filtering RGB; type 2 and 6, sample 8b
;---------------------------------------------------------------------
mov eax,ecx
; sub eax,[IHDR_data.Height]
xor edx,edx
mov ebx,3
cmp [IHDR_data.Color_type],byte 6
jne @f
inc ebx
@@:
cmp [IHDR_data.Bit_depth],byte 16
jne @f
shl ebx,1
@@:
div ebx
mov ecx,eax
cmp [IHDR_data.Bit_depth],byte 16
je .filter_Bit_depth_16
; jmp .ret_ok
;---------------------------------------------------------------------
cmp [IHDR_data.Interlace_method], byte 0 ; Interlaced
je @f
call filtering_RGB_Interlaced
jmp .converting_MSB_to_LSB
@@:
;---------------------------------------------------------------------
push edi
call filtering_RGB
pop edi
;---------------------------------------------------------------------
; converting MSB to LSB
; 24b = 1B x 3 sample
; 32b = 1B x 4 sample
.converting_MSB_to_LSB:
call .calculate_all_pixels
mov ebx,3
cmp [IHDR_data.Color_type],byte 6
jne @f
inc ebx
@@:
sub edi,ebx
@@:
add edi,ebx
mov al,[edi]
mov ah,[edi+2]
mov [edi+2],al
mov [edi],ah
dec ecx
jnz @r
jmp .ret_ok
;---------------------------------------------------------------------
.calculate_all_pixels:
mov ecx,[Image_Height]
imul ecx,[Image_Width]
ret
;---------------------------------------------------------------------
; Processing filtering RGB; type 2 and 6, sample 16b
;---------------------------------------------------------------------
.filter_Bit_depth_16:
cmp [IHDR_data.Interlace_method], byte 0 ; Interlaced
je @f
call filtering_RGB_16_Interlaced
jmp .converting_MSB_to_LSB_16
@@:
;---------------------------------------------------------------------
push edi
call filtering_RGB_16
pop edi
;---------------------------------------------------------------------
; converting MSB to LSB 48 or 64b
; 48b = 2B x 3 sample
; 64b = 2B x 4 sample
.converting_MSB_to_LSB_16:
call .calculate_all_pixels
mov ebx,3
cmp [IHDR_data.Color_type],byte 6
jne @f
inc ebx
@@:
shl ebx,1
sub edi,ebx
@@:
add edi,ebx
mov ax,[edi]
xchg al,ah
shl eax,16
mov ax,[edi+4]
xchg al,ah
mov [edi],ax
shr eax,16
mov [edi+4],ax
mov ax,[edi+2]
xchg al,ah
mov [edi+2],ax
; mov ax,[edi+6]
; xchg al,ah
; mov [edi+6],al
dec ecx
jnz @r
jmp .ret_ok
;---------------------------------------------------------------------
; Processing filtering Grayscale and RGB; type 2, 3 and 4, sample 8b
;---------------------------------------------------------------------
.PLTE_and_grayscale:
cmp [IHDR_data.Color_type],byte 4
jne @f
shr ecx,1
@@:
cmp [IHDR_data.Bit_depth],byte 16
jne @f
shr ecx,1
jmp .filter_grayscale_Bit_depth_16_1
@@:
;---------------------------------------------------------------------
cmp [IHDR_data.Interlace_method], byte 0 ; Interlaced
je @f
call filtering_grayscale_Interlaced
jmp .continue_1
@@:
;---------------------------------------------------------------------
push edi
call filtering_grayscale
pop edi
;---------------------------------------------------------------------
.continue_1:
cmp [IHDR_data.Color_type],byte 4
jne .ret_ok
;-------------------------------
; 8b or less
mov esi,edi
call .calculate_all_pixels
.convert_transp_to_notransp:
cld
lodsw
stosb
dec ecx
jnz .convert_transp_to_notransp
jmp .ret_ok
;---------------------------------------------------------------------
; Processing filtering Grayscale and RGB; type 2, 3 and 4, sample 16b
;---------------------------------------------------------------------
.filter_grayscale_Bit_depth_16_1:
cmp [IHDR_data.Interlace_method], byte 0 ; Interlaced
je @f
call filtering_grayscale_16_Interlaced
jmp .continue_2
@@:
;---------------------------------------------------------------------
push edi
call filtering_grayscale_16
pop edi
;---------------------------------------------------------------------
.continue_2:
cmp [IHDR_data.Color_type],byte 4
jne .ret_ok
;-------------------------------
; 16b
mov esi,edi
call .calculate_all_pixels
.convert_transp_to_notransp_1:
cld
lodsd
stosw
dec ecx
jnz .convert_transp_to_notransp_1
;---------------------------------------------------------------------
.ret_ok:
mov ecx,[unpacked_data]
mcall 68, 13,
xor eax,eax
;---------------------------------------------------------------------
.ret:
mov ebx,[pointer]
mov [ebx+8],eax ; store return code
mov eax,[raw_area]
mov [ebx+4],eax ; store RAW pointer
popad
ret 4
;---------------------------------------------------------------------
include 'filter.inc'
include 'proced.inc'
include 'fl_call.inc'
include 'interlac.inc'
;---------------------------------------------------------------------
Check_Header:
pushad
mov eax,dword [esp+36]
call check_header_1
jne no_png_file
popad
ret 4
;---------------------------------------------------------------------
Associations:
dd Associations.end - Associations
db 'PNG',0
.end:
db 0
;---------------------------------------------------------------------
align 4
EXPORTS:
dd szStart, START
dd szVersion, 0x00010002
dd szCheck, Check_Header
dd szAssoc, Associations
dd 0
szStart db 'START',0
szVersion db 'version',0
szCheck db 'Check_Header',0
szAssoc db 'Associations',0
;*****************************************************************************
; Chunks names
;*****************************************************************************
; Critical chunks
IHDR_name: db 'IHDR' ; Image header
PLTE_name: db 'PLTE' ; Palette
IDAT_name: db 'IDAT' ; Image data
IEND_name: db 'IEND' ; Image trailer
; Ancillary chunks
;tRNS_name: db 'tRNS' ; Transparency
;; Color space information
;gAMA_name: db 'gAMA' ; Image gamma
;cHRM_name: db 'cHRM' ; Primary chromaticities
;sRGB_name: db 'sRGB' ; Standard RGB color space
;iCCP_name: db 'iCCP' ; Embedded ICC profile
;; Textual information
;tEXt_name: db 'tEXt' ; Textual data
;zTXt_name: db 'zTXt' ; Compressed textual data
;iTXt_name: db 'iTXt' ; International textual data
;; Miscellaneous information
;bKGD_name: db 'bKGD' ; Background color
;pHYs_name: db 'pHYs' ; Physical pixel dimensions
;sBIT_name: db 'sBIT' ; Significant bits
;sPLT_name: db 'sPLT' ; Suggested palette
;hIST_name: db 'hIST' ; Palette histogram
;tIME_name: db 'tIME' ; Imagelast-modification time
;*****************************************************************************
calculate_Interlaced_counters:
.1: dd calculate_Interlaced_1
.2: dd calculate_Interlaced_2
.3: dd calculate_Interlaced_3
.4: dd calculate_Interlaced_4
.5: dd calculate_Interlaced_5
.6: dd calculate_Interlaced_6
.7: dd calculate_Interlaced_7
deflate_start_offset dd 0
pointer dd 0
image_file dd 0
file_size dd 0
raw_area dd 0
resolution dd 0
Chunk_pointer dd 0
next_Chunk dd 0
deflate_unpack dd 0
unpacked_data dd 0
;IDAT_raw_area dd 0
;IDAT_raw_counter dd 0
Interlaced_area dd 0
Starting_Row: dd 0
Starting_Col: dd 0
Row_Increment: dd 0
Col_Increment: dd 0
Interlaced_step dd 0
counter_IDAT_Chunk dd 0
;CRC32 dd 0
;CRC32table: rd 256
;Adler32 dd 0
Image_Width dd 0
Image_Height dd 0
IHDR_data:
.Width dd 0 ;+0
.Height dd 0 ;+4
.Bit_depth: db 0 ;+8
.Color_type: db 0 ;+9
.Compression_method: db 0 ;+10
.Filter_method: db 0 ;+11
.Interlace_method: db 0 ;+12
IDAT_CMF db 0 ; Compression Method and flags
IDAT_<EFBFBD><EFBFBD> db 0 ; Compression method
IDAT_CINFO db 0 ; Compression info
IDAT_FLG db 0 ; FLaGs
IDAT_FCHECK db 0 ;
IDAT_FDICT db 0 ; Preset dictionary
IDAT_FLEVEL db 0 ; Compression level
; "deflate" method (CM = 8) sets these flags:
; 0 - compressor used fastest algorithm
; 1 - compressor used fast algorithm
; 2 - compressor used default algorithm
; 3 - compressor used maximum compression, slowest algorithm
IDAT_DICT dd 0 ; dictionary identifier = Adler-32 checksum
BFINAL db 0 ; set 1 only if this is the last block of the data set
BTYPE db 0 ; specifies how the data are compressed:
; 00 - no compression
; 01 - compressed with fixed Huffman codes
; 10 - compressed with dynamic Huffman codes
; 11 - reserved (error)
line_filter_type dd 0 ; 0 None
; 1 Sub
; 2 Up
; 3 Averag
; 4 Paeth
first_line db 0
first_pixel db 0
previous_pixel_value:
rb 8
Paeth_filter:
.a: dw 0
.b: dw 0
.c: dw 0
.p dd 0
.pa dd 0
.pb dd 0
.pc dd 0
;*****************************************************************************
; Chunks pointer
;*****************************************************************************
IHDR:
.pointer dd 0
.size dd 0
PLTE:
.pointer dd 0
.size dd 0
IDAT:
.pointer dd 0
.size dd 0
IEND:
.pointer dd 0
.size dd 0
;tRNS:
;.pointer dd 0
;.size dd 0
;gAMA:
;.pointer dd 0
;.size dd 0
;cHRM:
;.pointer dd 0
;.size dd 0
;sRGB:
;.pointer dd 0
;.size dd 0
;iCCP:
;.pointer dd 0
;.size dd 0
;tEXt:
;.pointer dd 0
;.size dd 0
;zTXt:
;.pointer dd 0
;.size dd 0
;iTXt:
;.pointer dd 0
;.size dd 0
;bKGD:
;.pointer dd 0
;.size dd 0
;pHYs:
;.pointer dd 0
;.size dd 0
;sBIT:
;.pointer dd 0
;.size dd 0
;sPLT:
;.pointer dd 0
;.size dd 0
;hIST:
;.pointer dd 0
;.size dd 0
;tIME:
;.pointer dd 0
;.size dd 0