-
Notifications
You must be signed in to change notification settings - Fork 0
/
Comp_HuffShortDict.bas
459 lines (441 loc) · 14.5 KB
/
Comp_HuffShortDict.bas
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
Attribute VB_Name = "Comp_HuffShortDict"
Option Explicit
'This is a 2 run method
Private BitVal() As Long
Private CharVal() As Long
Public Sub Compress_HuffManShortDict(FileArray() As Byte)
Dim X As Long
Dim Y As Long
Dim Z As Long
Dim Char As Integer
Dim Bitlen As Integer
Dim FileLen As Long
Dim TelBits As Long
Dim TotBits As Long
Dim OutStream() As Byte
Dim TreeNodes(511, 4) As Long
Dim BitValue(7) As Byte
Dim ByteValue As Byte
Dim ByteBuff As String
Dim CheckSum As Integer
Dim NumberOfNodes As Integer
Dim OrgNumberOfNodes As Integer
Dim PackedSize As Long
Dim DictSize As Long
Dim OutPutSize As Long
Dim CharCount(255) As Long
Dim Bits(255) As String
Dim Nubits As String
Dim TempBits As String
Dim lTemp As Long
Dim lWeight As Long
Dim rWeight As Long
Dim MaxWeight As Long
Dim NowWeight As Long
Dim lNode As Integer
Dim rNode As Integer
Dim StringBuffer As String
Dim BitLens(16) As Integer
Dim CharLens(16) As String
Dim DictString As String
FileLen = UBound(FileArray)
OutPutSize = -1
If (FileLen = 0) Then
ReDim Preserve FileArray(2)
FileArray(0) = 72 'H
FileArray(1) = 69 'E
FileArray(2) = 48 '0
Exit Sub
End If
'treenodes(,0)=weight
'treenodes(,1)=Character
'treenodes(,2)=LeftNode
'treenodes(,3)=RightNode
'treenodes(,4)=ParentNode
'eerst gaan we de input doorlezen op zoek naar het meest voorkomende karakter
'en laten we dan ook gelijk de checksum maar doen
For X = 0 To UBound(FileArray)
CharCount(FileArray(X)) = CharCount(FileArray(X)) + 1
CheckSum = CheckSum Xor FileArray(X)
Next
'nu gaan we diegene die 0 maal voorkomen verwijderen
'en gelijk maar de blaadjes aanmaken
MaxWeight = UBound(FileArray) + 1
Z = -1
For X = 0 To 255
If CharCount(X) <> 0 Then
Z = Z + 1
TreeNodes(Z, 0) = CharCount(X)
TreeNodes(Z, 1) = X
TreeNodes(Z, 2) = -1 'leftnode
TreeNodes(Z, 3) = -1 'rightnode
TreeNodes(Z, 4) = -1 'parentnode
End If
Next
NumberOfNodes = Z
'nu gaan we de boom samenstallen (blaadjes verbinden met de stam)
OrgNumberOfNodes = NumberOfNodes
For X = NumberOfNodes + 1 To 2 Step -1
lWeight = MaxWeight * 2: rWeight = MaxWeight * 2
For Y = 0 To NumberOfNodes + 1
If TreeNodes(Y, 4) = -1 Then
NowWeight = TreeNodes(Y, 0)
If NowWeight < rWeight Or NowWeight < lWeight Then
If rWeight > lWeight Then
rWeight = NowWeight
rNode = Y
Else
lWeight = NowWeight
lNode = Y
End If
End If
End If
Next Y
NumberOfNodes = NumberOfNodes + 1
TreeNodes(lNode, 4) = NumberOfNodes
TreeNodes(rNode, 4) = NumberOfNodes
TreeNodes(NumberOfNodes, 0) = lWeight + rWeight
TreeNodes(NumberOfNodes, 1) = -1
TreeNodes(NumberOfNodes, 2) = lNode
TreeNodes(NumberOfNodes, 3) = rNode
TreeNodes(NumberOfNodes, 4) = -1
Next
'nu gaan we de bitsequence bepalen
'en tegelijk gaan we bereken hoe lang de gecodeerde file wordt
'en hoe groot of dat de dictionary wordt
TotBits = 0
For X = 0 To OrgNumberOfNodes
Char = TreeNodes(X, 1)
Y = X
Z = Y
Bitlen = 0
Do While TreeNodes(Y, 4) <> -1
Y = TreeNodes(Y, 4)
If TreeNodes(Y, 2) = Z Or TreeNodes(Y, 3) = Z Then
Bitlen = Bitlen + 1
Else
MsgBox "error creating bitpatern"
Exit Sub
End If
Z = Y
Loop
If TotBits < Bitlen Then TotBits = Bitlen
BitLens(Bitlen) = BitLens(Bitlen) + 1
CharLens(Bitlen) = CharLens(Bitlen) & Chr(Char)
PackedSize = PackedSize + (TreeNodes(X, 0) * Bitlen)
DictSize = DictSize + 2
Next
PackedSize = Int(PackedSize / 8) + Abs(1 * ((PackedSize / 8) - Int(PackedSize / 8) > 0))
DictString = Chr(TotBits)
For X = 1 To TotBits
If BitLens(X) = 256 Then
MsgBox "This code can't be compressed using this scheme"
Exit Sub
End If
DictString = DictString & Chr(BitLens(X))
Next
For X = 1 To TotBits
DictString = DictString + CharLens(X)
' Debug.Print X; " "; BitLens(X); " "; Len(CharLens(X))
Next
Call Create_Huffcodes(DictString, True)
'even kijken of de totale lengte van de gecomprimeerde file kleiner is dan het origineel
'en zo nee, dan de ongecomprimeerde file voorzien van header terugsturen
' If 3 + Len(DictString) + 1 + Len(CStr(UBound(FileArray))) + 1 + PackedSize > UBound(FileArray) Then
' ReDim Preserve FileArray(UBound(FileArray) + 3)
' Call CopyMem(FileArray(3), FileArray(0), FileLen + 1)
' FileArray(0) = 72
' FileArray(1) = 69
' FileArray(2) = 48
' FileArray(3) = 13
' Exit Sub
' End If
ReDim OutStream(3 + Len(DictString) + 1 + Len(CStr(UBound(FileArray))) + 1 + PackedSize)
'de data wordt inderdaad kleiner dus gaan we maar de header in elkaar zetten
'output as HE4 want dit is niet de standaard indeling van een huffman encoded file
For X = 0 To 7
BitValue(X) = 2 ^ X
Next
'opbouw van het gecomprimeerde bestand is
'ID van de file = 3 bytes in ASC
'grootte van de dictionary = 2 bytes in HEX
'de dictionary in ASC
' 1e = ascii code
' 2e = bitcount
' 3e = bitsequence :kan ook 4e en 5e worden
'de checksum van de te comprimeren file = 1 byte in asc
'de originele grootte van de te comprimeren file + vbcr
'de gecomprimeerde file
Call AddASC2Array(OutStream, OutPutSize, "HE4")
Call AddASC2Array(OutStream, OutPutSize, DictString)
Call AddASC2Array(OutStream, OutPutSize, Chr(CheckSum))
Call AddASC2Array(OutStream, OutPutSize, CStr(UBound(FileArray) + 1) & vbCr)
'nu gaan we de eigenlijke data coderen aan de hand van de dictionary
'GoTo einde
TelBits = 7
ByteValue = 0
For X = 0 To UBound(FileArray)
For Y = CharVal(FileArray(X)) - 1 To 0 Step -1 'bitlengte
If (BitVal(FileArray(X)) And 2 ^ Y) > 0 Then
ByteValue = ByteValue + BitValue(TelBits)
End If
TelBits = TelBits - 1
If TelBits = -1 Then
OutPutSize = OutPutSize + 1
OutStream(OutPutSize) = ByteValue
TelBits = 7
ByteValue = 0
End If
Next
Next
If TelBits <> 7 Then
OutPutSize = OutPutSize + 1
OutStream(OutPutSize) = ByteValue
End If
Einde:
ReDim Preserve OutStream(OutPutSize)
ReDim FileArray(OutPutSize)
Call CopyMem(FileArray(0), OutStream(0), OutPutSize + 1)
End Sub
Public Sub Decompress_HuffmanShortDict(FileArray() As Byte)
Dim X As Long
Dim Y As Long
Dim Z As Long
Dim TreeNodes(511, 4) As Long
Dim DeCompressed() As Byte
Dim Leaf(255, 1) As Byte
Dim ByteValue As Byte
Dim BitValue(7) As Byte
Dim NumberOfNodes As Integer
Dim CheckSum As Byte
Dim TestSum As Byte
Dim NuNode As Integer
Dim ToNode As Integer
Dim Char As Byte
Dim Bitlen As Byte
Dim Bits(255) As String
Dim TempBits As String
Dim StringBuffer As String
Dim TotBits As Long
Dim TelBits As Integer
Dim DictSize As Long
Dim InpPos As Long
Dim OrgLen As Long
Dim Nulen As Long
Dim DictString As String
Dim Waarde As Long
'eerst gaan we kijken of dit wel een goede file is
If FileArray(0) <> ASC("H") Or FileArray(1) <> ASC("E") Then
MsgBox "This is not a Huffman Compressed file"
Exit Sub
End If
If FileArray(2) = ASC("0") Then 'wel huffman maar niet gecomprimeerd
Call CopyMem(FileArray(0), FileArray(3), UBound(FileArray) - 3)
ReDim Preserve FileArray(UBound(FileArray) - 3)
' ReDim DeCompressed(UBound(FileArray) - 3)
' For X = 3 To UBound(FileArray)
' DeCompressed(X - 3) = FileArray(X)
' Next
Exit Sub
End If
If FileArray(2) <> ASC("4") Then 'niet gecomprimeerd met deze compressor
MsgBox "file corrupt or no Huffman compression"
Exit Sub
End If
InpPos = 3
'dictionary inlezen en er een bitsequence van maken
For X = 0 To 7
BitValue(X) = 2 ^ X
Next
TotBits = GetAscCodeFromArray(FileArray, InpPos)
DictString = DictString & Chr(TotBits)
TelBits = 0
For X = 1 To TotBits
ByteValue = GetAscCodeFromArray(FileArray, InpPos)
TelBits = TelBits + ByteValue
DictString = DictString & Chr(ByteValue)
Next
For X = 1 To TelBits
DictString = DictString & Chr(GetAscCodeFromArray(FileArray, InpPos))
Next
Call Create_Huffcodes(DictString, False)
'nugaan we de checksum lezen
CheckSum = GetAscCodeFromArray(FileArray, InpPos)
'nu gaan we de originele lengte lezen
Char = GetAscCodeFromArray(FileArray, InpPos)
Do While Char <> ASC(vbCr)
OrgLen = OrgLen & Chr(Char)
Char = GetAscCodeFromArray(FileArray, InpPos)
Loop
'nu gaan we de overige bytes decomprimeren
ReDim DeCompressed(OrgLen - 1)
Nulen = 0
NuNode = 0
StringBuffer = ""
TelBits = 7
Waarde = 0
TotBits = 0
Do While Nulen < OrgLen
If TelBits = -1 Then
InpPos = InpPos + 1
TelBits = 7
End If
Waarde = Waarde * 2
TotBits = TotBits + 1
If (FileArray(InpPos) And 2 ^ TelBits) > 0 Then
Waarde = Waarde + 1
End If
If TotBits = 20 Then
Err.Raise vbError, "DecompressHuffman", "We zijn de boom tot op een dood punt genaderd, waarschijnlijk is de header beschadigd"
Exit Sub
End If
If BitVal(Waarde) = TotBits Then 'gevonden
' If TreeNodes(NuNode, 4) = 255 Then 'we zijn bij het blaadje
DeCompressed(Nulen) = CharVal(Waarde)
TestSum = TestSum Xor DeCompressed(Nulen)
Nulen = Nulen + 1
Waarde = 0
TotBits = 0
End If
TelBits = TelBits - 1
Loop
If CheckSum <> TestSum Then
Err.Raise vbError, "Decompresshuffman", "Checksum is incorrect"
Exit Sub
End If
ReDim FileArray(OrgLen - 1)
Call CopyMem(FileArray(0), DeCompressed(0), OrgLen)
Exit Sub
Create_New_Node:
NumberOfNodes = NumberOfNodes + 1
TreeNodes(NumberOfNodes, 0) = -1
TreeNodes(NumberOfNodes, 1) = -1
TreeNodes(NumberOfNodes, 2) = -1
TreeNodes(NumberOfNodes, 3) = NuNode
TreeNodes(NumberOfNodes, 4) = -1
ToNode = NumberOfNodes
Return
End Sub
Private Function BinToDec(Binair As String) As Integer
Dim X As Integer
If Len(Binair) > 8 Then
Err.Raise vbError, "BinToDec", "This binary number dont fit in 1 byte"
Exit Function
End If
Do While Len(Binair) <> 8
Binair = Binair & "0"
Loop
For X = 1 To 8
BinToDec = BinToDec + (Mid(Binair, X, 1) * 2 ^ (8 - X))
Next
End Function
Private Function DecToBin(Waarde As Integer) As String
Dim X As Integer
For X = 7 To 0 Step -1
DecToBin = DecToBin & CStr(Abs((Waarde And (2 ^ X)) > 0))
Next
End Function
Private Sub AddASC2Array(WichArray() As Byte, StartPos As Long, Text As String)
Dim X As Long
For X = 1 To Len(Text)
WichArray(StartPos + X) = ASC(Mid(Text, X, 1))
Next
StartPos = StartPos + Len(Text)
End Sub
Private Function GetAscCodeFromArray(WichArray() As Byte, StartPos As Long) As Integer
GetAscCodeFromArray = WichArray(StartPos)
StartPos = StartPos + 1
End Function
Private Sub AddHEX2Array(WichArray() As Byte, StartPos As Long, Waarde As Long, TotBytes As Integer)
Dim HexWaarde As String
Dim X As Long
HexWaarde = Right(String(2 * TotBytes, "0") & Hex(Waarde), 2 * TotBytes)
For X = 1 To TotBytes
WichArray(StartPos + X) = "&h" & Mid(HexWaarde, (X - 1) * 2 + 1, 2)
Next
StartPos = StartPos + TotBytes
End Sub
Private Function GetHexValFromArray(WichArray() As Byte, StartPos As Long, TotBytes As Integer) As Long
Dim X As Long
Dim TempHex As String
For X = 0 To TotBytes - 1
TempHex = TempHex & Right("00" & Hex(WichArray(StartPos + X)), 2)
Next
StartPos = StartPos + TotBytes
GetHexValFromArray = "&h" & TempHex
End Function
Private Sub Create_Huffcodes(DictString As String, ForCompress As Boolean)
Dim Code As Long
Dim TotKars As Integer
Dim TotLengs As Integer
Dim ReadPos As Integer
Dim bl_count() As Integer
Dim TreeLang() As Integer
Dim MaxLang As Integer
Dim TreeCode() As Long
Dim next_code() As Long
Dim Chars() As Integer
' Dim Bits As Integer
Dim BitString As String
Dim Bitlen As Integer
Dim Numbits As Integer
Dim MaxBits As Integer
Dim maxcode As Long
Dim n As Integer
Dim X As Integer
Dim Y As Integer
Dim Lang As Integer
' Call Create_Bytes2
MaxBits = ASC(Mid(DictString, 1, 1))
ReDim Preserve bl_count(MaxBits)
ReadPos = 2
MaxLang = -1
For X = 1 To MaxBits
Numbits = ASC(Mid(DictString, ReadPos, 1))
If Numbits > 0 Then
Bitlen = X
bl_count(Bitlen) = Numbits
ReDim Preserve TreeLang(MaxLang + Numbits)
For Y = 1 To Numbits
MaxLang = MaxLang + 1
TreeLang(MaxLang) = Bitlen
Next
End If
ReadPos = ReadPos + 1
Next
ReDim TreeCode(MaxLang)
ReDim next_code(MaxBits)
ReDim Chars(MaxLang)
For X = 0 To MaxLang
Chars(X) = ASC(Mid(DictString, ReadPos, 1))
ReadPos = ReadPos + 1
Next
maxcode = 0
Code = 0
For n = 1 To MaxBits
Code = (Code + bl_count(n - 1)) * 2
next_code(n) = Code
Next
For n = 0 To MaxLang
Lang = TreeLang(n)
TreeCode(n) = next_code(Lang)
next_code(Lang) = next_code(Lang) + 1
If maxcode < next_code(Lang) Then maxcode = next_code(Lang)
Next
If ForCompress = True Then
ReDim BitVal(255)
ReDim CharVal(255)
For X = 0 To MaxLang
BitVal(Chars(X)) = TreeCode(X)
CharVal(Chars(X)) = TreeLang(X)
'Debug.Print Chars(X); " "; DecToBin1(CLng(TreeCode(X)), CLng(TreeLang(X)))
Next
Else
ReDim BitVal(maxcode)
ReDim CharVal(maxcode)
For X = 0 To MaxLang
BitVal(TreeCode(X)) = TreeLang(X)
CharVal(TreeCode(X)) = Chars(X)
Next
End If
End Sub