Домой Классы Статические функции Перечисления (ENUM) Структуры (STRUCTURE)

{Lzw|_decompression_for_GIF}


(включая защищенные члены)



CLASS {Lzw|_decompression_for_GIF}
,
UNTESTED, BYTES, BITWISE:






IMPORT : 
{Stream}
, 
{Memory_stream}
, 
{System_functions}
, 
{Long_int}
 .


 


CONSTANT INT 
:

          NO_LZW_CODE = 4096

          GIF_BUFFER_SIZE = 4096 
 .








--------------------------------------------------------- 'from KOLGif.pas'









FUNCTION 
Decode_gif_data|_based_on_KOLGif

(

     {Memory_stream} 
In|put_data
, 

     INT 
Width|_pixels
, 

     INT 
Height|_pixels
, 

     INT 
Bpp|_bits_per_pixel
, 

     BOOL 
Interlace
, 

     INT 
Initial_code_size
)
 ==> {Memory_stream} 
 , NEW






 This code is based on KOLGif.pas (DecodeGifData) which is based on RxGif.pas
 which originally was based on source of freeware GBM program by Andy Key.





{Memory_stream} 
In|put_data





INDEXING 
BYTE

INT 
in_pos|ition






INT 
in_size|_bytes






{Memory_stream} 
Out|_codes





 






METHOD 
decode_gif_data

 ==> {Memory_stream} 
 , NEW







INT 
Min_code_size







------------------------------------------------------------ 'read context'


INT 
Inx|_1111111






INT 
Size|2222222






BYTE 
Buf|er_read[260]






INT 
Code_size






INT 
Read_mask







---------------------------------------------------------- 'output context'


INT 
W|idth_picture






INT 
H|eight_picture






INT 
X|_position






INT 
Y|_position






INT 
Bpp|_Bits_per_pixel






BOOL 
Interlace







--------------------------------------------------------------- 'pass info'


INT 
Pass|_pass






INT 
Line_ident






INT 
Curr_line_data||Current_line_data







---------------------------------------------------------- 'corrupted flag'


BOOL 
Corrupted





 






METHOD 
read_byte

 ==> BYTE 







INT 
read_count
 , DEBUG





   






METHOD 
read_code

 ==> INT 











METHOD 
output|_value_bits

(
INT 
Value|_to_out
)











METHOD 
interlace_step

(
INT 
Y_prev|ious
)
 ==> INT 







END