;;================================================================================================;;
;;//// gif.asm //// (c) mike.dld, 2007-2008 //////////////////////////////////////////////////////;;
;;================================================================================================;;
;;//// Partial (c) by Willow, Diamond and HidnPlayr //////////////////////////////////////////////;;
;;================================================================================================;;
;; ;;
;; This file is part of Common development libraries (Libs-Dev). ;;
;; ;;
;; Libs-Dev is free software: you can redistribute it and/or modify it under the terms of the GNU ;;
;; Lesser General Public License as published by the Free Software Foundation, either version 2.1 ;;
;; of the License, or (at your option) any later version. ;;
;; ;;
;; Libs-Dev is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without ;;
;; even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ;;
;; Lesser General Public License for more details. ;;
;; ;;
;; You should have received a copy of the GNU Lesser General Public License along with Libs-Dev. ;;
;; If not, see <http://www.gnu.org/licenses/>. ;;
;; ;;
;;================================================================================================;;
;; ;;
;; References: ;;
;; 1. GIF LITE v3.0 (2004-2007) ;;
;; by Willow and Diamond ;;
;; svn://kolibrios.org/programs/media/gifview/trunk/gif_lite.inc ;;
;; 2. "GIF File Format Summary" ;;
;; from "Encyclopedia of Graphics File Formats" by O'Reilly ;;
;; http://www.fileformat.info/format/gif/ ;;
;; 3. "LZW and GIF explained" (1987) ;;
;; by Steve Blackstock, IEEE ;;
;; http://www.cis.udel.edu/~amer/CISC651/lzw.and.gif.explained.html ;;
;; 4. "Graphics Interchange Format (tm)" (June 15, 1987) ;;
;; by CompuServe Incorporated ;;
;; http://examples.oreilly.de/english_examples/gff/CDROM/GFF/VENDSPEC/GIF/GIF87A.TXT ;;
;; 5. "Graphics Interchange Format (sm)" (July 31, 1990) ;;
;; by CompuServe Incorporated ;;
;; http://examples.oreilly.de/english_examples/gff/CDROM/GFF/VENDSPEC/GIF/GIF89A.TXT ;;
;; ;;
;;================================================================================================;;
include 'gif.inc'
;;================================================================================================;;
proc img.is.gif _data, _length ;//////////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Determine if raw data could be decoded (is in GIF format) ;;
;;------------------------------------------------------------------------------------------------;;
;> _data = raw data as read from file/stream ;;
;> _length = data length ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = false / true ;;
;;================================================================================================;;
cmp [_length], 6
jb .nope
mov eax, [_data]
cmp dword[eax], 'GIF8'
jne .nope
cmp word[eax + 4], '7a'
je .yep
cmp word[eax + 4], '9a'
je .yep
.nope:
xor eax, eax
ret
.yep:
xor eax, eax
inc eax
ret
endp
;;================================================================================================;;
proc img.decode.gif _data, _length ;//////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Decode data into image if it contains correctly formed raw data in GIF format ;;
;;------------------------------------------------------------------------------------------------;;
;> _data = raw data as read from file/stream ;;
;> _length = data length ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = 0 (error) or pointer to image ;;
;;================================================================================================;;
locals
img dd ?
global_color_table dd ?
global_color_table_size dd ?
endl
push ebx
; img.is.gif is called by caller (img.decode)
; stdcall img.is.gif, [_data], [_length]
; or eax, eax
; jz .error
mov [global_color_table_size], 0
mov ebx, [_data]
test [ebx + gif.Header.lsd.Packed], gif.LSD.Packed.GlobalColorTableFlag
jz @f
lea eax, [ebx + sizeof.gif.Header]
mov [global_color_table], eax
mov cl, [ebx + gif.Header.lsd.Packed]
and cl, gif.LSD.Packed.SizeOfGlobalColorTableMask
shr cl, gif.LSD.Packed.SizeOfGlobalColorTableShift
mov eax, 2
shl eax, cl
mov [global_color_table_size], eax
lea eax, [eax * 3]
add ebx, eax
@@: add ebx, sizeof.gif.Header
mov [img], 0
; @@: cmp byte[ebx + gif.Block.Introducer], gif.Block.Introducer.Extension
; jne .next_image
; cmp byte[ebx + gif.Extension.Label], gif.Extension.Label.Comment
; jne .error
; add ebx, sizeof.gif.Extension
; stdcall ._.skip_data
; mov ebx, eax
; jmp @b
.next_image:
stdcall img._.new
or eax, eax
jz .error
mov edx, [img]
mov [eax + Image.Previous], edx
test edx, edx
jz @f
mov [edx + Image.Next], eax
@@:
mov [img], eax
mov edx, eax
mov [eax + Image.Type], Image.bpp8
invoke mem.alloc, sizeof.gif.Image
or eax, eax
jz .error
mov [edx + Image.Extended], eax
stdcall ._.process_extensions
cmp byte[ebx + gif.Block.Introducer], gif.Block.Introducer.ImageDescriptor
jne .error
movzx eax, [ebx + gif.ImageDescriptor.Width]
movzx ecx, [ebx + gif.ImageDescriptor.Height]
stdcall img._.resize_data, [img], eax, ecx
or eax, eax
jz .error
mov esi, ebx
mov edi, [edx + Image.Extended]
mov ecx, sizeof.gif.ImageDescriptor
rep movsb
mov edi, [edx + Image.Palette]
mov esi, [global_color_table]
mov ecx, [global_color_table_size]
test [ebx + gif.ImageDescriptor.Packed], gif.ID.Packed.LocalColorTableFlag
jz @f
lea esi, [ebx + sizeof.gif.ImageDescriptor]
mov cl, [ebx + gif.ImageDescriptor.Packed]
and cl, gif.ID.Packed.SizeOfLocalColorTableMask
shr cl, gif.ID.Packed.SizeOfLocalColorTableShift
mov eax, 2
shl eax, cl
mov ecx, eax
lea eax, [eax*3]
add ebx, eax
@@:
lodsd
dec esi
bswap eax
shr eax, 8
stosd
loop @b
add ebx, sizeof.gif.ImageDescriptor
stdcall ._.process_image
.decoded:
or eax, eax
jz @f
stdcall img.destroy, [img]
jmp .error
@@: mov eax, [img]
ret
.error:
mov eax, [img]
test eax, eax
jz @f
stdcall img.destroy, eax
@@:
xor eax, eax
pop ebx
ret
endp
;;================================================================================================;;
proc img.encode.gif _img, _p_length ;/////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Encode image into raw data in GIF format ;;
;;------------------------------------------------------------------------------------------------;;
;> _img = pointer to image ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = 0 (error) or pointer to encoded data ;;
;< _p_length = encoded data length ;;
;;================================================================================================;;
xor eax, eax
ret
endp
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;! Below are private procs you should never call directly from your code ;;
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;;================================================================================================;;
proc img.decode.gif._.skip_data ;/////////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? --- TBD --- ;;
;;------------------------------------------------------------------------------------------------;;
;> ebx = pointer to data blocks array ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = pointer to data right after data blocks array ;;
;;================================================================================================;;
push ecx
xor ecx, ecx
@@: mov cl, [esi]
or cl, cl
jz @f
lea esi, [esi + ecx + 1]
jmp @b
@@: pop ecx
ret
endp
;;================================================================================================;;
proc img.decode.gif._.process_extensions ;////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? --- TBD --- ;;
;;------------------------------------------------------------------------------------------------;;
;> ebx = raw image data ;;
;> edx = image data ;;
;;------------------------------------------------------------------------------------------------;;
;< --- TBD --- ;;
;;================================================================================================;;
push edx
mov esi, ebx
.next_block:
mov al, [esi + gif.Block.Introducer]
cmp al, gif.Block.Introducer.Extension
je .ext_block
; cmp al, gif.Block.Introducer.ImageDescriptor
; je .exit
; cmp al, gif.Block.Introducer.EndOfFile
; je .exit
jmp .exit
.ext_block:
mov al, [esi + gif.Extension.Label]
cmp al, gif.Extension.Label.PlainText
je .plain_text_ext
cmp al, gif.Extension.Label.GraphicsControl
je .graphics_control_ext
cmp al, gif.Extension.Label.Comment
je .comment_ext
cmp al, gif.Extension.Label.Application
je .application_ext
jmp .exit
.plain_text_ext:
add esi, gif.PlainTextExtension.PlainTextData
stdcall img.decode.gif._.skip_data
jmp .next_ext_block
.graphics_control_ext:
push edi
mov edi, [edx + Image.Extended]
add edi, gif.Image.gce
mov ecx, sizeof.gif.GraphicsControlExtension
rep movsb
pop edi
jmp .next_ext_block
.comment_ext:
add esi, gif.CommentExtension.CommentData
stdcall img.decode.gif._.skip_data
jmp .next_ext_block
.application_ext:
add esi, gif.ApplicationExtension.ApplicationData
stdcall img.decode.gif._.skip_data
jmp .next_ext_block
.next_ext_block:
mov al, [esi + gif.Block.Introducer]
cmp al, gif.Block.Introducer.EndOfData
jne .exit
inc esi
jmp .next_block
.exit:
mov ebx, esi
pop edx
ret
endp
;;================================================================================================;;
proc img.decode.gif._.process_image ;/////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? --- TBD --- ;;
;;------------------------------------------------------------------------------------------------;;
;> ebx = raw image data ;;
;> edx = image data ;;
;;------------------------------------------------------------------------------------------------;;
;< --- TBD --- ;;
;;================================================================================================;;
locals
width dd ?
img_start dd ?
img_end dd ?
row_end dd ?
pass dd ?
codesize dd ?
compsize dd ?
workarea dd ?
block_ofs dd ?
bit_count dd ?
CC dd ?
EOI dd ?
endl
invoke mem.alloc, 16 * 1024
mov [workarea], eax
or eax, eax
jz .error
mov ecx, [edx + Image.Width]
mov [width], ecx
mov eax, [edx + Image.Height]
imul eax, ecx
mov [img_end], eax
inc eax
mov [row_end], eax
and [pass], 0
mov eax, [edx + Image.Extended]
test [eax + gif.Image.info.Packed], gif.ID.Packed.InterleaceFlag
jz @f
mov [row_end], ecx
@@: mov esi, ebx
mov edi, [edx + Image.Data]
push edi
movzx ecx, byte[esi]
inc esi
mov [codesize], ecx
inc [codesize]
mov edi, [workarea]
xor eax, eax
lodsb ; eax - block_count
add eax, esi
mov [block_ofs], eax
mov [bit_count], 8
mov eax, 1
shl eax, cl
mov [CC], eax
mov ecx, eax
inc eax
mov [EOI], eax
mov eax, gif.Null shl 16
.filltable:
stosd
inc eax
loop .filltable
pop edi
mov [img_start], edi
add [img_end], edi
add [row_end], edi
.reinit:
mov edx, [EOI]
inc edx
push [codesize]
pop [compsize]
call .get_symbol
cmp eax, [CC]
je .reinit
call .output
.cycle:
movzx ebx, ax
call .get_symbol
cmp eax, edx
jae .notintable
cmp eax, [CC]
je .reinit
cmp eax, [EOI]
je .end
call .output
.add:
mov ecx, [workarea]
mov [ecx + edx * 4], ebx
cmp edx, 0x00000FFF
jae .cycle
inc edx
bsr ebx, edx
cmp ebx, [compsize]
jne .noinc
inc [compsize]
.noinc:
jmp .cycle
.notintable:
push eax
mov eax, ebx
call .output
push ebx
movzx eax, bx
call .output
pop ebx eax
jmp .add
.end:
mov edi, [img_end]
xor eax, eax
.exit:
cmp [workarea], 0
je @f
invoke mem.free, [workarea]
@@: xor eax, eax
ret
.error:
cmp [workarea], 0
je @f
invoke mem.free, [workarea]
@@: xor eax, eax
inc eax
ret
;;------------------------------------------------------------------------------------------------;;
img.decode.gif._.process_image.get_symbol:
mov ecx, [compsize]
push ecx
xor eax, eax
.shift:
ror byte[esi], 1
rcr eax,1
dec [bit_count]
jnz .loop1
inc esi
cmp esi, [block_ofs]
jb .noblock
push eax
xor eax, eax
lodsb
test eax, eax
jnz .nextbl
mov eax, [EOI]
sub esi, 2
add esp, 8
jmp .exit
.nextbl:
add eax, esi
mov [block_ofs], eax
pop eax
.noblock:
mov [bit_count], 8
.loop1:
loop .shift
pop ecx
rol eax, cl
.exit:
xor ecx, ecx
retn
;;------------------------------------------------------------------------------------------------;;
img.decode.gif._.process_image.output:
push esi eax edx
mov edx, [workarea]
.next:
pushw [edx + eax * 4]
mov ax, [edx + eax * 4 + 2]
inc ecx
cmp ax, gif.Null
jnz .next
shl ebx, 16
mov bx, [esp]
.loop2:
pop ax
stosb
cmp edi, [row_end]
jb .norowend
mov eax, [width]
push eax
sub edi, eax
add eax, eax
cmp [pass], 3
je @f
add eax, eax
cmp [pass], 2
je @f
add eax, eax
@@: add edi, eax
pop eax
cmp edi, [img_end]
jb .nextrow
mov edi, [img_start]
inc [pass]
add edi, eax
cmp [pass], 3
je @f
add edi, eax
cmp [pass], 2
je @f
add edi, eax
add edi, eax
@@:
.nextrow:
add eax, edi
mov [row_end], eax
xor eax, eax
.norowend:
loop .loop2
pop edx eax esi
retn
endp
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;! Below is private data you should never use directly from your code ;;
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;