]> Creatis software - gdcm.git/blob - src/gdcmRLEFrame.cxx
BUG: Remove my previous hack now this is properly fixed in gdcmBinEntry by JPR
[gdcm.git] / src / gdcmRLEFrame.cxx
1 /*=========================================================================
2                                                                                 
3   Program:   gdcm
4   Module:    $RCSfile: gdcmRLEFrame.cxx,v $
5   Language:  C++
6   Date:      $Date: 2005/02/05 01:37:09 $
7   Version:   $Revision: 1.7 $
8                                                                                 
9   Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
10   l'Image). All rights reserved. See Doc/License.txt or
11   http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
12                                                                                 
13      This software is distributed WITHOUT ANY WARRANTY; without even
14      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15      PURPOSE.  See the above copyright notices for more information.
16                                                                                 
17 =========================================================================*/
18                                                                                 
19 #include "gdcmRLEFrame.h"
20 #include "gdcmDebug.h"
21                                                                                 
22 namespace gdcm
23 {
24 //-------------------------------------------------------------------------
25 // Constructor / Destructor
26
27 //-----------------------------------------------------------------------------
28 // Public
29 void RLEFrame::SetOffset(unsigned int id,long offset)
30 {
31    gdcmAssertMacro(id<15);
32    Offset[id] = offset;
33 }
34
35 long RLEFrame::GetOffset(unsigned int id)
36 {
37    gdcmAssertMacro(id<15);
38    return Offset[id];
39 }
40
41 void RLEFrame::SetLength(unsigned int id,long length)
42 {
43    gdcmAssertMacro(id<15);
44    Length[id] = length;
45 }
46
47 long RLEFrame::GetLength(unsigned int id)
48 {
49    gdcmAssertMacro(id<15);
50    return Length[id];
51 }
52
53 uint8_t *RLEFrame::ReadAndDecompressRLEFrame( uint8_t *subRaw,
54                                           long rawSegmentSize,
55                                           std::ifstream *fp )
56 {
57    // Loop on the fragments
58    for( unsigned int k = 1; k <= NumberOfFragments; k++ )
59    {
60       // First thing need to reset file to proper position:
61       fp->seekg(Offset[k], std::ios::beg);
62       ReadAndDecompressRLEFragment(subRaw, Length[k],
63                                    rawSegmentSize, fp);
64       subRaw += rawSegmentSize;
65    }
66
67    return subRaw;
68 }
69
70 /**
71  * \brief Implementation of the RLE decoding algorithm for decompressing
72  *        a RLE fragment. [refer to PS 3.5-2003, section G.3.2 p 86]
73  * @param subRaw Sub region where the decoded fragment should be placed.
74  * @param fragmentSize The length of the binary fragment as found on the disk.
75  * @param rawSegmentSize The expected length of the fragment ONCE Raw.
76  * @param fp File Pointer: on entry the position should be the one of
77  *        the fragment to be decoded.
78  */
79 bool RLEFrame::ReadAndDecompressRLEFragment( uint8_t *subRaw,
80                                              long fragmentSize,
81                                              long rawSegmentSize,
82                                              std::ifstream *fp )
83 {
84    int8_t count;
85    long numberOfOutputBytes = 0;
86    long numberOfReadBytes = 0;
87
88
89    while( numberOfOutputBytes < rawSegmentSize )
90    {
91       fp->read( (char*)&count, 1 );
92       numberOfReadBytes += 1;
93       if ( count >= 0 )
94       // Note: count <= 127 comparison is always true due to limited range
95       //       of data type int8_t [since the maximum of an exact width
96       //       signed integer of width N is 2^(N-1) - 1, which for int8_t
97       //       is 127].
98       {
99          fp->read( (char*)subRaw, count + 1);
100          numberOfReadBytes   += count + 1;
101          subRaw     += count + 1;
102          numberOfOutputBytes += count + 1;
103       }
104       else
105       {
106          if ( count <= -1 && count >= -127 )
107          {
108             int8_t newByte;
109             fp->read( (char*)&newByte, 1);
110             numberOfReadBytes += 1;
111             for( int i = 0; i < -count + 1; i++ )
112             {
113                subRaw[i] = newByte;
114             }
115             subRaw     += -count + 1;
116             numberOfOutputBytes += -count + 1;
117          }
118       }
119       // if count = 128 output nothing
120                                                                                 
121       if ( numberOfReadBytes > fragmentSize )
122       {
123          gdcmWarningMacro( "Read more bytes than the segment size.");
124          return false;
125       }
126    }
127    return true;
128 }
129
130 //-----------------------------------------------------------------------------
131 // Protected
132
133 //-----------------------------------------------------------------------------
134 // Private
135
136 //-----------------------------------------------------------------------------
137 // Print
138 /**
139  * \brief        Print self.
140  * @param indent Indentation string to be prepended during printing.
141  * @param os     Stream to print to.
142  */
143 void RLEFrame::Print( std::ostream &os, std::string indent )
144 {
145    os << indent
146       << "--- fragments"
147       << std::endl;
148    for ( unsigned int i = 0; i < NumberOfFragments; i++ )
149    {
150       os << indent
151          << "   offset : " <<  Offset[i]
152          << "   length : " <<  Length[i]
153          << std::endl;
154    }
155 }
156
157 //-----------------------------------------------------------------------------
158 } // end namespace gdcm
159