[Freepv-cvs] SF.net SVN: freepv: [142] freepv/branches/branch_leonox/src/libfreepv/Utils /signatures.cpp

[<le...@us...>]

Revision: 142
          http://freepv.svn.sourceforge.net/freepv/?rev=142&view=rev
Author:   leonox
Date:     2008-04-06 04:59:43 -0700 (Sun, 06 Apr 2008)

Log Message:
-----------


Modified Paths:
--------------
    freepv/branches/branch_leonox/src/libfreepv/Utils/signatures.cpp

Modified: freepv/branches/branch_leonox/src/libfreepv/Utils/signatures.cpp
===================================================================
--- freepv/branches/branch_leonox/src/libfreepv/Utils/signatures.cpp	2008-03-15 11:02:11 UTC (rev 141)
+++ freepv/branches/branch_leonox/src/libfreepv/Utils/signatures.cpp	2008-04-06 11:59:43 UTC (rev 142)
@@ -23,6 +23,7 @@
  */
 
 #include "signatures.h"
+#include <iostream>
 
 namespace FPV{
 namespace Utils{
@@ -34,8 +35,8 @@
   char png_size=4;
   short png_sig[]={0x5089, 0x474E, 0x0A0D, 0x0A1A};
   //MOV Signature
-  char mov_size=2;
-  short mov_sig[]={0x6F6D, 0x766F};
+  char mov_size=4;
+  short mov_sig[]={0x0000, 0x0000, 0x6F6D, 0x766F};
   //XML Signature
   char xml_size=3;
   short xml_sig[]={0x3F3C, 0x6D78, 0x206C};
@@ -67,22 +68,31 @@
       do{
          fread(&number,2,1,p_file);
          
-         //in case of MOV skip the first 4 bytes.
-         if(type==2&&i<2)
-            mov_sig[i]=number;
-         //std::cerr<<"Lectura:"<<std::hex<<signature[type][i]<<std::endl;
-         equal=signature[type][i++]^number;
-         //std::cerr.setf( ios_base::hex );
-         //std::cerr<<"Comparada con:"<<std::hex<<number<<std::endl<<std::endl;
+         //In case of MOV skip the first 4 bytes.
+         //by asigning the first 4 read bytes
+         //to the MOV signature
+         if(type==2&&i<2) mov_sig[i]=number;
          
-      }while(!equal&&i<sig_sizes[type]);
+         //The comparation is made by using a bit XOR operator
+	 //we look for the double implication <->, so the result
+	 //of the XOR operation is negated.
+	 equal=!(signature[type][i++]^number);
+	
+         //std::cerr<<"Lecture:"<<std::hex<<signature[type][i]<<std::endl;
+         //std::cerr<<"Compared with:"<<std::hex<<number<<std::endl<<std::endl;
+	 //std::cerr<<"Equal: "<<std::hex<<equal<<std::endl<<std::endl;*/
+         
+      }while(equal&&i<sig_sizes[type]);
    
-      if(!equal){
+      if(equal){
+         //The signature was found,
+	 //There is no need to keep looking for...
          break;
       }
+      //Check next probable signature.
       type++;
 
-    }while(equal&&type<sig_types_num);
+    }while(type<sig_types_num);
    
     fclose(p_file);
 
@@ -96,58 +106,12 @@
       return("XML");
     if(type==4)
       return("DCR");
+
+    //In other case return Unknown
     return("Unknown");
    
   }
 
-  std::string CheckMagicBytes(const char* filename, std::string type){
-    FILE * p_file;
-    p_file=fopen(filename, "rb");
-    short number;
-    short equal=0;
-    char i, type_num; 
-   
-    if(p_file==NULL){
-	return "Unknown";
-    }
-
-    if(type=="JPG"||type=="JPEG")
-      type_num = 0;
-    else if(type=="PNG")
-      type_num = 1;
-    else if(type=="QTVR")
-      type_num = 2;
-    else if(type=="XML")
-      type_num = 3;
-    else if(type=="DCR")
-      type_num = 4;
-    else
-      type_num = 5;
-
-    i=0;
-    do{
-      if(type_num>4) break;
-      fread(&number,2,1,p_file);
-         
-      //in case of MOV skip the first 4 bytes.
-      if(type_num==2&&i<2)
-	mov_sig[i]=number;
-      //std::cerr<<"Lecture:"<<std::hex<<signature[type_num][i]<<std::endl;
-      equal=signature[type_num][i++]^number;
-      //std::cerr.setf( ios_base::hex );
-      //std::cerr<<"Compared with:"<<std::hex<<number<<std::endl<<std::endl;
-         
-    }while(!equal&&i<sig_sizes[type_num]);
-  
-    fclose(p_file);
-
-    if(!equal)
-      return type;
-    else
-      return type="Unknown";
-
-  }
-
 }//Utils
 }//namespace
 


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