Base 64 encoder / decoder

[Dav]

This thread has re-sparked my interest in binary to text encoders.  Always looking for something better than base64 to output code safe to post on forums.  Has anyone tried to implement base91 before? 

Edit: Nevermind-- looks like base91 is patented.

- Dav

[SMcNeill]

@Dav

You posted an encoding routine which you use, a while back, which:

The encoded bytes range from ASC 48  "0"  to ASC 111 "o".  111 - 48  = 63 (64 characters). In that range, the comma and quotes are avoided.

I had a similar method going for my stuff, but then I ran into an issue, which might affect your encoder as well:

58 is ":", which in QB64 is a command separator.

My solution was simply to change my code so that it started at 59 instead, and thus that problem is forever avoided and I don't have to enclose the output in quotes if I want to use it for something like DATA statements.  ;)

[Dav]

Thanks for the tip, @SMcNeill.  Yes, I would need to change that if my output wasn't in quotes.  One problem I did have to fix in my last few encoders here was using the @ symbol.  That was interfering with posted code because of the forums way of using @ to note members, so I had to swap it out with an unused character.

Edit: Thread about the @ problem here.

- Dav

[SpriggsySpriggs]

One problem I did have to fix in my last few encoders here was using the @ symbol.  That was interfering with posted code because of the forums way of using @ to note members, so I had to swap it out with an unused character.

@Dav

I remember that! It feels like such a long time ago. Your code revolutionized includes for me.

By the way, how did you hide the URL and show just "here"? I haven't figured out how to do that. Never mind. Figured out how to do that

[bplus]

I found we were on this very same subject last year! Petr and AndyA were doing things.

I am wondering if all this data packing slows program loads?

[Petr]

I am wondering if all this data packing slows program loads?

My version slows down, AndyA's version practically not at all. This is the difference between using the logical AND operator (AndyA version) and / or strings (my version).

[Dav]

I haven't tested mine for speed, but I imagine it's slow as molasses. Not familiar with AndyA's version (I didn't hang around here too much last year) but I'll search for it.   Maybe these encoding schemes would make a good test in a benchmark program!

- Dav

[NOVARSEG]

Here is base 256 to base 128 encoder / decoder


detected bug . . . .fixed

Code: QB64: [Select]

1. 'BASE 128 encoder  / decoder
2. 'input string is encoded then decoded
3.  
4. DIM b8, b7, b6, b5, b4, b3, b2, b1 AS INTEGER
5. DIM s8 AS STRING
6. DIM s7 AS STRING
7. DIM s6 AS STRING
8. DIM s5 AS STRING
9. DIM s4 AS STRING
10. DIM s3 AS STRING
11. DIM s2 AS STRING
12. DIM s1 AS STRING
13. DIM n AS INTEGER
14. DIM string1 AS STRING 'input string
15. DIM string2 AS STRING 'output string
16. _FULLSCREEN
17. string1 = "ASCII stands for American Standard Code for Information Interchange..." + CHR$(166) + CHR$(167) + CHR$(168) + CHR$(169) + CHR$(170) + CHR$(171) + CHR$(172)
18. 'string1 = "ASCII stands for American Standard Code for Information Interchange..."
19.  
20. 'string1 must be a multiple of 7 bytes
21.  
22. PRINT "string1"
23. PRINT string1
24. PRINT
25. PRINT
26. n = 45 'offset into ASCII table
27.  
28. 'Encode
29. FOR x% = 1 TO LEN(string1) STEP 7
30.     b7 = ASC(MID$(string1, x%, 1))
31.     b6 = ASC(MID$(string1, x% + 1, 1))
32.     b5 = ASC(MID$(string1, x% + 2, 1))
33.     b4 = ASC(MID$(string1, x% + 3, 1))
34.     b3 = ASC(MID$(string1, x% + 4, 1))
35.     b2 = ASC(MID$(string1, x% + 5, 1))
36.     b1 = ASC(MID$(string1, x% + 6, 1))
37.  
38.     IF b7 >= 128 THEN
39.         b7 = b7 - 128
40.         b8 = 64
41.     END IF
42.     s7 = CHR$(b7 + n)
43.  
44.     IF b6 >= 128 THEN
45.         b6 = b6 - 128
46.         b8 = b8 + 32
47.     END IF
48.     s6 = CHR$(b6 + n)
49.  
50.     IF b5 >= 128 THEN
51.         b5 = b5 - 128
52.         b8 = b8 + 16
53.     END IF
54.     s5 = CHR$(b5 + n)
55.  
56.     IF b4 >= 128 THEN
57.         b4 = b4 - 128
58.         b8 = b8 + 8
59.     END IF
60.     s4 = CHR$(b4 + n)
61.  
62.     IF b3 >= 128 THEN
63.         b3 = b3 - 128
64.         b8 = b8 + 4
65.     END IF
66.     s3 = CHR$(b3 + n)
67.  
68.     IF b2 >= 128 THEN
69.         b2 = b2 - 128
70.         b8 = b8 + 2
71.     END IF
72.     s2 = CHR$(b2 + n)
73.  
74.     IF b1 >= 128 THEN
75.         b1 = b1 - 128
76.         b8 = b8 + 1
77.     END IF
78.     s1 = CHR$(b1 + n)
79.  
80.     s8 = CHR$(b8 + n)
81.  
82.     string2 = string2 + (s8 + s7 + s6 + s5 + s4 + s3 + s2 + s1)
83.  
84. NEXT x%
85.  
86. string1 = ""
87.  
88. PRINT "string1 encoded"
89. PRINT string2
90. PRINT
91. PRINT
92.  
93.  
94. 'Decode
95. FOR x% = 1 TO LEN(string2) STEP 8
96.  
97.     b8 = ASC(MID$(string2, x%, 1)) - n
98.     b7 = ASC(MID$(string2, x% + 1, 1)) - n
99.     b6 = ASC(MID$(string2, x% + 2, 1)) - n
100.     b5 = ASC(MID$(string2, x% + 3, 1)) - n
101.     b4 = ASC(MID$(string2, x% + 4, 1)) - n
102.     b3 = ASC(MID$(string2, x% + 5, 1)) - n
103.     b2 = ASC(MID$(string2, x% + 6, 1)) - n
104.     b1 = ASC(MID$(string2, x% + 7, 1)) - n
105.  
106.     IF b8 >= 64 THEN
107.         b8 = b8 - 64
108.         b7 = b7 + 128
109.     END IF
110.     s7 = CHR$(b7)
111.  
112.     IF b8 >= 32 THEN
113.         b8 = b8 - 32
114.         b6 = b6 + 128
115.     END IF
116.     s6 = CHR$(b6)
117.  
118.     IF b8 >= 16 THEN
119.         b8 = b8 - 16
120.         b5 = b5 + 128
121.     END IF
122.     s5 = CHR$(b5)
123.  
124.     IF b8 >= 8 THEN
125.         b8 = b8 - 8
126.         b4 = b4 + 128
127.     END IF
128.     s4 = CHR$(b4)
129.  
130.     IF b8 >= 4 THEN
131.         b8 = b8 - 4
132.         b3 = b3 + 128
133.     END IF
134.     s3 = CHR$(b3)
135.  
136.     IF b8 >= 2 THEN
137.         b8 = b8 - 2
138.         b2 = b2 + 128
139.     END IF
140.     s2 = CHR$(b2)
141.  
142.     IF b8 >= 1 THEN
143.         b8 = b8 - 1
144.         b1 = b1 + 128
145.     END IF
146.     s1 = CHR$(b1)
147.  
148.     string1 = string1 + (s7 + s6 + s5 + s4 + s3 + s2 + s1)
149.  
150.  
151. NEXT x%
152.  
153. PRINT "decoded"
154. "
155. PRINT string1
156. PRINT
157. PRINT
158.  
159. END
160.  

[bplus]

FOR x% = 1 TO LEN(string1) STEP 7
    b7 = ASC(MID$(string1, x%, 1))
    b6 = ASC(MID$(string1, x% + 1, 1))
    b5 = ASC(MID$(string1, x% + 2, 1))
    b4 = ASC(MID$(string1, x% + 3, 1))
    b3 = ASC(MID$(string1, x% + 4, 1))
    b2 = ASC(MID$(string1, x% + 5, 1))
    b1 = ASC(MID$(string1, x% + 6, 1))

Oh I think I see the error...

Anyway here is a tip:

Code: QB64: [Select]

1. s$ = "string"
2. FOR i = 1 TO LEN(s$)
3.     PRINT ASC(s$, i); "  =  "; ASC(MID$(s$, i, 1)) '   <<<<<<<<<<<<< tip
4. NEXT

[NOVARSEG]

Thanks bplus

code updated

Code: QB64: [Select]

1. 'BASE 128 encoder  / decoder
2. 'input string is encoded then decoded
3.  
4. DIM b8, b7, b6, b5, b4, b3, b2, b1 AS INTEGER
5. DIM s8 AS STRING
6. DIM s7 AS STRING
7. DIM s6 AS STRING
8. DIM s5 AS STRING
9. DIM s4 AS STRING
10. DIM s3 AS STRING
11. DIM s2 AS STRING
12. DIM s1 AS STRING
13. DIM n AS INTEGER
14. DIM string1 AS STRING 'input string
15. DIM string2 AS STRING 'output string
16. _FULLSCREEN
17. string1 = "ASCII stands for American Standard Code for Information Interchange..." + CHR$(166) + CHR$(167) + CHR$(168) + CHR$(169) + CHR$(170) + CHR$(171) + CHR$(172)
18. 'string1 = "ASCII stands for American Standard Code for Information Interchange..."
19.  
20. 'string1 must be a multiple of 7 bytes
21.  
22. PRINT "string1"
23. PRINT string1
24. PRINT
25. PRINT
26. n = 45 'offset into ASCII table
27.  
28. 'Encode
29. FOR x% = 1 TO LEN(string1) STEP 7
30.  
31.     b7 = ASC(string1, x%)
32.     b6 = ASC(string1, x% + 1)
33.     b5 = ASC(string1, x% + 2)
34.     b4 = ASC(string1, x% + 3)
35.     b3 = ASC(string1, x% + 4)
36.     b2 = ASC(string1, x% + 5)
37.     b1 = ASC(string1, x% + 6)
38.  
39.     IF b7 >= 128 THEN
40.         b7 = b7 - 128
41.         b8 = 64
42.     END IF
43.     s7 = CHR$(b7 + n)
44.  
45.     IF b6 >= 128 THEN
46.         b6 = b6 - 128
47.         b8 = b8 + 32
48.     END IF
49.     s6 = CHR$(b6 + n)
50.  
51.     IF b5 >= 128 THEN
52.         b5 = b5 - 128
53.         b8 = b8 + 16
54.     END IF
55.     s5 = CHR$(b5 + n)
56.  
57.     IF b4 >= 128 THEN
58.         b4 = b4 - 128
59.         b8 = b8 + 8
60.     END IF
61.     s4 = CHR$(b4 + n)
62.  
63.     IF b3 >= 128 THEN
64.         b3 = b3 - 128
65.         b8 = b8 + 4
66.     END IF
67.     s3 = CHR$(b3 + n)
68.  
69.     IF b2 >= 128 THEN
70.         b2 = b2 - 128
71.         b8 = b8 + 2
72.     END IF
73.     s2 = CHR$(b2 + n)
74.  
75.     IF b1 >= 128 THEN
76.         b1 = b1 - 128
77.         b8 = b8 + 1
78.     END IF
79.     s1 = CHR$(b1 + n)
80.  
81.     s8 = CHR$(b8 + n)
82.  
83.     string2 = string2 + (s8 + s7 + s6 + s5 + s4 + s3 + s2 + s1)
84.  
85. NEXT x%
86.  
87. string1 = ""
88.  
89. PRINT "string1 encoded"
90. PRINT string2
91. PRINT
92. PRINT
93.  
94.  
95. 'Decode
96. FOR x% = 1 TO LEN(string2) STEP 8
97.  
98.     b8 = ASC(string2, x%) - n
99.     b7 = ASC(string2, x% + 1) - n
100.     b6 = ASC(string2, x% + 2) - n
101.     b5 = ASC(string2, x% + 3) - n
102.     b4 = ASC(string2, x% + 4) - n
103.     b3 = ASC(string2, x% + 5) - n
104.     b2 = ASC(string2, x% + 6) - n
105.     b1 = ASC(string2, x% + 7) - n
106.  
107.     IF b8 >= 64 THEN
108.         b8 = b8 - 64
109.         b7 = b7 + 128
110.     END IF
111.     s7 = CHR$(b7)
112.  
113.     IF b8 >= 32 THEN
114.         b8 = b8 - 32
115.         b6 = b6 + 128
116.     END IF
117.     s6 = CHR$(b6)
118.  
119.     IF b8 >= 16 THEN
120.         b8 = b8 - 16
121.         b5 = b5 + 128
122.     END IF
123.     s5 = CHR$(b5)
124.  
125.     IF b8 >= 8 THEN
126.         b8 = b8 - 8
127.         b4 = b4 + 128
128.     END IF
129.     s4 = CHR$(b4)
130.  
131.     IF b8 >= 4 THEN
132.         b8 = b8 - 4
133.         b3 = b3 + 128
134.     END IF
135.     s3 = CHR$(b3)
136.  
137.     IF b8 >= 2 THEN
138.         b8 = b8 - 2
139.         b2 = b2 + 128
140.     END IF
141.     s2 = CHR$(b2)
142.  
143.     IF b8 >= 1 THEN
144.         b8 = b8 - 1
145.         b1 = b1 + 128
146.     END IF
147.     s1 = CHR$(b1)
148.  
149.     string1 = string1 + (s7 + s6 + s5 + s4 + s3 + s2 + s1)
150.  
151.  
152. NEXT x%
153.  
154. PRINT "decoded"
155. PRINT string1
156. PRINT
157. PRINT
158.  
159. END
160.  

[SMcNeill]

One note:

DIM b8, b7, b6, b5, b4, b3, b2, b1 AS INTEGER

You do realize only b1 is an INTEGER?  The other b's are SINGLE.

[NOVARSEG]

Thanks SMcNeill
It's amazing it still worked!

Updated

Code: QB64: [Select]

1. 'BASE 128 encoder  / decoder
2. 'input string is encoded then decoded
3.  
4. DIM b8 AS INTEGER
5. DIM b7 AS INTEGER
6. DIM b6 AS INTEGER
7. DIM b5 AS INTEGER
8. DIM b4 AS INTEGER
9. DIM b3 AS INTEGER
10. DIM b2 AS INTEGER
11. DIM b1 AS INTEGER
12.  
13. DIM s8 AS STRING
14. DIM s7 AS STRING
15. DIM s6 AS STRING
16. DIM s5 AS STRING
17. DIM s4 AS STRING
18. DIM s3 AS STRING
19. DIM s2 AS STRING
20. DIM s1 AS STRING
21. DIM n AS INTEGER
22. DIM string1 AS STRING 'input string
23. DIM string2 AS STRING 'output string
24. _FULLSCREEN
25. string1 = "ASCII stands for American Standard Code for Information Interchange..." + CHR$(166) + CHR$(1) + CHR$(168) + CHR$(169) + CHR$(170) + CHR$(171) + CHR$(172)
26. 'string1 = "ASCII stands for American Standard Code for Information Interchange..."
27.  
28. 'string1 must be a multiple of 7 bytes
29.  
30. PRINT "string1"
31. PRINT string1
32. PRINT
33. PRINT
34. n = 65 'offset into ASCII table  starts at asc 65 "A"  to  asc 192
35. 'no quotes, comma, :, @
36.  
37. 'Encode
38. FOR x% = 1 TO LEN(string1) STEP 7
39.  
40.     b7 = ASC(string1, x%)
41.     b6 = ASC(string1, x% + 1)
42.     b5 = ASC(string1, x% + 2)
43.     b4 = ASC(string1, x% + 3)
44.     b3 = ASC(string1, x% + 4)
45.     b2 = ASC(string1, x% + 5)
46.     b1 = ASC(string1, x% + 6)
47.  
48.     IF b7 >= 128 THEN
49.         b7 = b7 - 128
50.         b8 = 64
51.     END IF
52.     s7 = CHR$(b7 + n)
53.  
54.     IF b6 >= 128 THEN
55.         b6 = b6 - 128
56.         b8 = b8 + 32
57.     END IF
58.     s6 = CHR$(b6 + n)
59.  
60.     IF b5 >= 128 THEN
61.         b5 = b5 - 128
62.         b8 = b8 + 16
63.     END IF
64.     s5 = CHR$(b5 + n)
65.  
66.     IF b4 >= 128 THEN
67.         b4 = b4 - 128
68.         b8 = b8 + 8
69.     END IF
70.     s4 = CHR$(b4 + n)
71.  
72.     IF b3 >= 128 THEN
73.         b3 = b3 - 128
74.         b8 = b8 + 4
75.     END IF
76.     s3 = CHR$(b3 + n)
77.  
78.     IF b2 >= 128 THEN
79.         b2 = b2 - 128
80.         b8 = b8 + 2
81.     END IF
82.     s2 = CHR$(b2 + n)
83.  
84.     IF b1 >= 128 THEN
85.         b1 = b1 - 128
86.         b8 = b8 + 1
87.     END IF
88.     s1 = CHR$(b1 + n)
89.  
90.     s8 = CHR$(b8 + n)
91.  
92.     string2 = string2 + (s8 + s7 + s6 + s5 + s4 + s3 + s2 + s1)
93.  
94. NEXT x%
95.  
96. string1 = ""
97.  
98. PRINT "string1 encoded"
99. PRINT string2
100. PRINT
101. PRINT
102.  
103.  
104. 'Decode
105. FOR x% = 1 TO LEN(string2) STEP 8
106.  
107.     b8 = ASC(string2, x%) - n
108.     b7 = ASC(string2, x% + 1) - n
109.     b6 = ASC(string2, x% + 2) - n
110.     b5 = ASC(string2, x% + 3) - n
111.     b4 = ASC(string2, x% + 4) - n
112.     b3 = ASC(string2, x% + 5) - n
113.     b2 = ASC(string2, x% + 6) - n
114.     b1 = ASC(string2, x% + 7) - n
115.  
116.     IF b8 >= 64 THEN
117.         b8 = b8 - 64
118.         b7 = b7 + 128
119.     END IF
120.     s7 = CHR$(b7)
121.  
122.     IF b8 >= 32 THEN
123.         b8 = b8 - 32
124.         b6 = b6 + 128
125.     END IF
126.     s6 = CHR$(b6)
127.  
128.     IF b8 >= 16 THEN
129.         b8 = b8 - 16
130.         b5 = b5 + 128
131.     END IF
132.     s5 = CHR$(b5)
133.  
134.     IF b8 >= 8 THEN
135.         b8 = b8 - 8
136.         b4 = b4 + 128
137.     END IF
138.     s4 = CHR$(b4)
139.  
140.     IF b8 >= 4 THEN
141.         b8 = b8 - 4
142.         b3 = b3 + 128
143.     END IF
144.     s3 = CHR$(b3)
145.  
146.     IF b8 >= 2 THEN
147.         b8 = b8 - 2
148.         b2 = b2 + 128
149.     END IF
150.     s2 = CHR$(b2)
151.  
152.     IF b8 >= 1 THEN
153.         b8 = b8 - 1
154.         b1 = b1 + 128
155.     END IF
156.     s1 = CHR$(b1)
157.  
158.     string1 = string1 + (s7 + s6 + s5 + s4 + s3 + s2 + s1)
159.  
160.  
161. NEXT x%
162.  
163. PRINT "decoded"
164. PRINT string1
165. PRINT
166. PRINT
167.  
168. END
169.  

[Petr]

@Dav: Here is it: https://www.qb64.org/forum/index.php?topic=2041.0

[Dav]

@Dav: Here is it: https://www.qb64.org/forum/index.php?topic=2041.0

Thank you @Petr!

- Dav

[NOVARSEG]

Base 256 to base 128 decoder using _SHR , _SHL,  AND

There are no conditional statements or loops other than one FOR NEXT which is need to process either 7 or 8 bytes at a time

How it works.  7 bytes are encoded at a time.  The MSB of the 7 input bytes form an 8th byte.

Decoding left shifts the 8th byte to obtain the MSB which is  added to the original byte.
Code should run pretty fast.

Code: QB64: [Select]

1. 'BASE 128 encoder  / decoder   using _SHR , _SHL,  AND
2. 'input string is encoded then decoded
3.  
4. DIM b8 AS INTEGER
5. DIM b7 AS INTEGER
6. DIM b6 AS INTEGER
7. DIM b5 AS INTEGER
8. DIM b4 AS INTEGER
9. DIM b3 AS INTEGER
10. DIM b2 AS INTEGER
11. DIM b1 AS INTEGER
12.  
13. DIM n AS INTEGER
14. DIM string1 AS STRING
15. DIM string2 AS STRING
16.  
17. _FULLSCREEN
18. string1 = "ASCII stands for American Standard Code for Information Interchange..." + CHR$(127) + CHR$(128) + CHR$(129) + CHR$(130) + CHR$(1) + CHR$(2) + CHR$(1)
19.  
20.  
21. 'string1 must be a multiple of 7 bytes
22.  
23. PRINT "string1"
24. PRINT string1
25. PRINT
26. PRINT
27.  
28. n = 65 'offset into ASCII table  starts at asc 65 "A"  to  asc 192
29. 'no quotes, comma, :, @
30.  
31. 'Encode
32. FOR x% = 1 TO LEN(string1) STEP 7
33.  
34.     b7 = ASC(string1, x%)
35.     b6 = ASC(string1, x% + 1)
36.     b5 = ASC(string1, x% + 2)
37.     b4 = ASC(string1, x% + 3)
38.     b3 = ASC(string1, x% + 4)
39.     b2 = ASC(string1, x% + 5)
40.     b1 = ASC(string1, x% + 6)
41.  
42.  
43.     b8 = (128 AND b7) + b8
44.     b8 = _SHR(b8, 1)
45.     b7 = (b7 AND 127) + n
46.  
47.     b8 = (128 AND b6) + b8
48.     b8 = _SHR(b8, 1)
49.     b6 = (b6 AND 127) + n
50.  
51.     b8 = (128 AND b5) + b8
52.     b8 = _SHR(b8, 1)
53.     b5 = (b5 AND 127) + n
54.  
55.     b8 = (128 AND b4) + b8
56.     b8 = _SHR(b8, 1)
57.     b4 = (b4 AND 127) + n
58.  
59.     b8 = (128 AND b3) + b8
60.     b8 = _SHR(b8, 1)
61.     b3 = (b3 AND 127) + n
62.  
63.     b8 = (128 AND b2) + b8
64.     b8 = _SHR(b8, 1)
65.     b2 = (b2 AND 127) + n
66.  
67.     b8 = (128 AND b1) + b8
68.     b8 = _SHR(b8, 1)
69.     b1 = (b1 AND 127) + n
70.  
71.     b8 = b8 + n
72.  
73.  
74.     string2 = string2 + (CHR$(b8) + CHR$(b7) + CHR$(b6) + CHR$(b5) + CHR$(b4) + CHR$(b3) + CHR$(b2) + CHR$(b1))
75.  
76.  
77. NEXT x%
78.  
79. string1 = ""
80.  
81. PRINT "string1 encoded"
82. PRINT string2
83. PRINT
84. PRINT
85.  
86.  
87. 'Decode
88. FOR x% = 1 TO LEN(string2) STEP 8
89.  
90.     b8 = ASC(string2, x%) - n
91.     b7 = ASC(string2, x% + 1) - n
92.     b6 = ASC(string2, x% + 2) - n
93.     b5 = ASC(string2, x% + 3) - n
94.     b4 = ASC(string2, x% + 4) - n
95.     b3 = ASC(string2, x% + 5) - n
96.     b2 = ASC(string2, x% + 6) - n
97.     b1 = ASC(string2, x% + 7) - n
98.  
99.  
100.     b8 = _SHL(b8, 1)
101.     b1 = (128 AND b8) + b1
102.  
103.     b8 = _SHL(b8, 1)
104.     b2 = (128 AND b8) + b2
105.  
106.     b8 = _SHL(b8, 1)
107.     b3 = (128 AND b8) + b3
108.  
109.     b8 = _SHL(b8, 1)
110.     b4 = (128 AND b8) + b4
111.  
112.     b8 = _SHL(b8, 1)
113.     b5 = (128 AND b8) + b5
114.  
115.     b8 = _SHL(b8, 1)
116.     b6 = (128 AND b8) + b6
117.  
118.     b8 = _SHL(b8, 1)
119.     b7 = (128 AND b8) + b7
120.  
121.  
122.     string1 = string1 + (CHR$(b7) + CHR$(b6) + CHR$(b5) + CHR$(b4) + CHR$(b3) + CHR$(b2) + CHR$(b1))
123.  
124. NEXT x%
125.  
126. PRINT "decoded"
127. PRINT string1
128. PRINT
129. PRINT
130.  
131. END
132.