X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=src%2FgdcmRLEFrame.cxx;h=d22e21fd9af237285574dbcb5b470406d5e1d241;hb=713d0f3d28a6176fab6d57e031633061dc7354a7;hp=7ed3a0a91b66f4bf1e67017a1bfce2375ba12561;hpb=a4cff04fcd2023f798a9f1ef6bc9307269abd185;p=gdcm.git

diff --git a/src/gdcmRLEFrame.cxx b/src/gdcmRLEFrame.cxx
index 7ed3a0a9..d22e21fd 100644
--- a/src/gdcmRLEFrame.cxx
+++ b/src/gdcmRLEFrame.cxx
@@ -3,8 +3,8 @@
   Program:   gdcm
   Module:    $RCSfile: gdcmRLEFrame.cxx,v $
   Language:  C++
-  Date:      $Date: 2005/01/26 11:42:02 $
-  Version:   $Revision: 1.3 $
+  Date:      $Date: 2007/05/23 14:18:11 $
+  Version:   $Revision: 1.13 $
                                                                                 
   Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
   l'Image). All rights reserved. See Doc/License.txt or
@@ -19,28 +19,13 @@
 #include "gdcmRLEFrame.h"
 #include "gdcmDebug.h"
                                                                                 
-namespace gdcm
+namespace GDCM_NAME_SPACE
 {
+//-------------------------------------------------------------------------
+// Constructor / Destructor
 
-/**
- * \brief        Print self.
- * @param indent Indentation string to be prepended during printing.
- * @param os     Stream to print to.
- */
-void RLEFrame::Print( std::ostream &os, std::string indent )
-{
-   os << indent
-      << "--- fragments"
-      << std::endl;
-   for ( unsigned int i = 0; i < NumberFragments; i++ )
-   {
-      os << indent
-         << "   offset : " <<  Offset[i]
-         << "   length : " <<  Length[i]
-         << std::endl;
-   }
-}
-
+//-----------------------------------------------------------------------------
+// Public
 void RLEFrame::SetOffset(unsigned int id,long offset)
 {
    gdcmAssertMacro(id<15);
@@ -65,5 +50,111 @@ long RLEFrame::GetLength(unsigned int id)
    return Length[id];
 }
 
+uint8_t *RLEFrame::ReadAndDecompressRLEFrame( uint8_t *subRaw,
+                                          long rawSegmentSize,
+                                          std::ifstream *fp )
+{
+   // Loop on the fragments
+   for( unsigned int k = 1; k <= NumberOfFragments; k++ )
+   {
+      // First thing need to reset file to proper position:
+      fp->seekg(Offset[k], std::ios::beg);
+      ReadAndDecompressRLEFragment(subRaw, Length[k],
+                                   rawSegmentSize, fp);
+      subRaw += rawSegmentSize;
+   }
+
+   return subRaw;
+}
+
+/**
+ * \brief Implementation of the RLE decoding algorithm for decompressing
+ *        a RLE fragment. [refer to PS 3.5-2003, section G.3.2 p 86]
+ * @param subRaw Sub region where the decoded fragment should be placed.
+ * @param fragmentSize The length of the binary fragment as found on the disk.
+ * @param rawSegmentSize The expected length of the fragment ONCE Raw.
+ * @param fp File Pointer: on entry the position should be the one of
+ *        the fragment to be decoded.
+ */
+bool RLEFrame::ReadAndDecompressRLEFragment( uint8_t *subRaw,
+                                             long fragmentSize,
+                                             long rawSegmentSize,
+                                             std::ifstream *fp )
+{
+   int8_t count;
+   long numberOfOutputBytes = 0;
+   long numberOfReadBytes = 0;
+
+   while( numberOfOutputBytes < rawSegmentSize )
+   {
+      fp->read( (char*)&count, 1 );
+      numberOfReadBytes += 1;
+      if ( count >= 0 )
+      // Note: count <= 127 comparison is always true due to limited range
+      //       of data type int8_t [since the maximum of an exact width
+      //       signed integer of width N is 2^(N-1) - 1, which for int8_t
+      //       is 127].
+      {
+         fp->read( (char*)subRaw, count + 1);
+         numberOfReadBytes   += count + 1;
+         subRaw     += count + 1;
+         numberOfOutputBytes += count + 1;
+      }
+      else
+      {
+         if ( count <= -1 && count >= -127 )
+         {
+            int8_t newByte;
+            fp->read( (char*)&newByte, 1);
+            numberOfReadBytes += 1;
+            for( int i = 0; i < -count + 1; i++ )
+            {
+               subRaw[i] = newByte;
+            }
+            subRaw     += -count + 1;
+            numberOfOutputBytes += -count + 1;
+         }
+      }
+      // if count = 128 output nothing
+                                                                                
+      if ( numberOfReadBytes > fragmentSize )
+      {
+         gdcmWarningMacro( "Read more bytes (" << numberOfReadBytes
+                              << " ) than the segment size. (" 
+                              << fragmentSize << ")" );
+         return false;
+      }
+   }
+   return true;
+}
+
+//-----------------------------------------------------------------------------
+// Protected
+
+//-----------------------------------------------------------------------------
+// Private
+
+//-----------------------------------------------------------------------------
+// Print
+/**
+ * \brief        Print self.
+ * @param indent Indentation string to be prepended during printing.
+ * @param os     Stream to print to.
+ */
+void RLEFrame::Print( std::ostream &os, std::string const &indent )
+{
+   os << indent
+      << "--- fragments"
+      << std::endl;
+   for ( unsigned int i = 0; i < NumberOfFragments; i++ )
+   {
+      os << indent
+         << "   offset : " <<  Offset[i]
+         << "   length : " <<  Length[i]
+         << std::endl;
+   }
+}
+
+//-----------------------------------------------------------------------------
 } // end namespace gdcm