Encode and Decode problems.

Hello.

I am having a very hard time trying to encode a file and then decode it again so i can end up with the original file.

I want to transform the content in the original file into base 64. I've tried and succeeded with decimal and hexadecimal bases.
Ex. When i have 'abcde' in a text file and i encode it into 97 98 99 100 101, and then decode it back in a differnet file i have "abcde"

When i use hex base .. i have 'abcde' and then enconde it as 61 62 63 64 65.. when i decode it it gives me back abcde..

THe table looks liie this.


Base is the encoding mode.
Alphabet is the letters it has. Example: the decimal alphabet has 10 "letters"( 0 1 2 3 4 5 6 7 8 9) and a space === 11.

PROPORTION MEANS HOW FAST THE ENCODING IS DONE.



-----------------------------------
| BASE | ALPHABET | PROPORTION |
|---------|----------|------------|
| Dec | 11 | 3.5 |
|---------|----------|------------|
| Hex | 16 | 2.5 |
|---------|----------|------------|
| Base 64 | 64 | 1.33 |
|---------|----------|------------|
| Base 85 | 85 | 1.25 |
|---------|----------|------------|
| Base 85 | 200 |close to one|
|---------|----------|------------|

Here is my code for base 64. However, as mentioned before is not working. Could anyone please help me.
;---------------------------------------------------------
.386
assume cs:main_seg, ds:main_seg
main_seg segment
org 100h
;-----------------------------variables-------------------
start:
jmp real_start
help_content db "Syntex is : code [inputfile] [outputfile]",'$'
tail_length byte 0
length1 byte 0
file_in db 30 dup(0),'$'
file_out_en db 30 dup(0),'$'

inp db 3 dup(?),'$'
oute db 4 dup (?),'$'
buffsize1 equ 3
buffsize2 equ 4
inh1 dw ?
outh1 dw ?

;----------------------------program starts here------------------------------
real_start:



mov bx, 80h ;points bx to the arguments to get the lenght
mov al, [bx]
mov tail_length, al ;store total length of the argument to tail_lenght
dec tail_length ;decrease lenght by one since first character is space and we are not going to count space
mov bx, 81h ;//points bx to get the argument
mov al, [bx] ;//move first argument to al
cmp al, 13 ;//compare if there was no argument
jne next1 ;//if there are arguments, go to analize them
syntax_error:
mov ah, 09h ;//if no argument, show help and stop application
lea dx, help_content
int 21h
call exit

next1:
inc bx ;eleminate the space as i said before
mov dx, offset file_in ;point argument1 to dx

mov cl, tail_length ;Max loop counter set to total lenght of the argument

part1: ;get first part of the agrument
mov al, byte ptr [bx]
inc bx
xchg dx, bx
mov byte ptr [bx], al
inc bx
xchg dx, bx
cmp al, 20h
je getpart2
inc length1
loop part1

getpart2:
mov bx, 82h
sub cx, cx
mov cl, length1
add bx, cx
mov al, [bx]

space_remover2:
cmp al, 13
je syntax_error
inc bx
inc length1
mov al, [bx]
cmp al, 13
je syntax_error
cmp al, 20h
je space_remover2
mov dx, offset file_out_en
mov cl, tail_length
sub cl, length1

part2:
mov al, byte ptr [bx]
inc bx
xchg dx, bx
mov byte ptr [bx], al
inc bx
xchg dx, bx

loop part2



;------------opening input file
mov ah, 3dh ;to open a existing file
mov al,0 ;mode = read only
mov dx, offset file_in ;point the input file to dx
int 21h ;call Ms-dos
jc exit ;quit if error
mov inh1, ax ;move handlar to inh.


;-------------creating output file

mov ah, 3ch ;creat output file
sub cx, cx ; attributes clear
mov dx, offset file_out_en ;point the output file to dx
int 21h ;call Ms-dos
jc exit ;quit if error
mov outh1, ax ;mode handlare to outh

e:

;-----------reading from the input file
mov ah, 3fh ;read the file
mov bx, inh1 ;point input file handler
mov cx, buffsize1 ;seting the size to read at a time
mov dx, offset inp ;pointing the buffer where to store
int 21h ;call ms-dos
jc exit ;quit if error

;--------------add 0 at the end of the file if total caracter is not divided by zero
cmp ax, 2
jne n1
mov inp[2], 0
n1:
cmp ax, 1
jne n2
mov inp[1],0
mov inp[2],0
n2:


or ax, ax
jz done ;jump to done if ax=0


;---------take 3 character (8bit) input form inp vaiable and store 4 character (6bit) to outp vairable
L1:
mov al, inp[0]

shr al, 2
add al, 49d
mov oute[0], al

L2:
mov ax, word ptr inp[0]
xchg al, ah
shl ax, 6
shr ax, 10
add al, 49d
mov oute[1], al

L3:
mov ax, word ptr inp[1]
xchg al, ah
shl ax, 4
shr ax, 10
add al, 49d
mov oute[2], al
L4:
mov al, inp[2]
shl al, 2
shr al,2
add al, 49d
mov oute[3], al
;--------------------------write it to the file


;-----------writing buffer to the file


mov cx, buffsize2 ;set number of bye to write
mov ah, 40h ;write the file
mov bx, outh1 ;point to the output file
mov dx, offset oute ;write from buffer
int 21h ;call dos
jc exit ;quit if error


;----------------------------------------------------

jmp e
done:


;---------close files
mov ah, 3eh
mov bx, inh1
int 21h

mov ah, 3eh
mov bx, outh1
int 21h

exit:
int 20h
main_seg ends
end start