mistserver/lib/nal.cpp

77 lines
2 KiB
C++

#include "nal.h"
NAL_Unit::NAL_Unit( ) {
}
NAL_Unit::NAL_Unit( std::string & InputData ) {
ReadData( InputData );
}
bool NAL_Unit::ReadData( std::string & InputData ) {
bool AnnexB = false;
if( InputData[0] == 0x00 && InputData[1] == 0x00 ) {
if( InputData[2] == 0x01 ) {
AnnexB = true;
}
if( InputData[2] == 0x00 && InputData[3] == 0x01 ) {
InputData.erase(0,1);
AnnexB = true;
}
}
if( AnnexB ) {
MyData = "";
InputData.erase(0,3);//Intro Bytes
bool FinalByteRead = false;
while( !FinalByteRead ) {
MyData += InputData[0];
InputData.erase(0,1);
if( InputData[0] == 0x00 && InputData[1] == 0x00 ) {
if( InputData[2] == 0x01 ) {
FinalByteRead = true;
}
if( InputData[2] == 0x00 && InputData[3] == 0x01 ) {
InputData.erase(0,1);
FinalByteRead= true;
}
}
}
} else {
if( InputData.size() < 4 ) { return false; }
int UnitLen = (InputData[0] << 24) + (InputData[1] << 16) + (InputData[2] << 8) + InputData[3];
if( InputData.size() < 4+UnitLen ) { return false; }
InputData.erase(0,4);//Remove Length
MyData = InputData.substr(0,UnitLen);
InputData.erase(0,UnitLen);//Remove this unit from the string
}
return true;
}
std::string NAL_Unit::AnnexB( bool LongIntro ) {
std::string Result;
if( MyData.size() ) {
if( LongIntro ) { Result += (char)0x00; }
Result += (char)0x00;
Result += (char)0x00;
Result += (char)0x01;//Annex B Lead-In
Result += MyData;
}
return Result;
}
std::string NAL_Unit::SizePrepended( ) {
std::string Result;
if( MyData.size() ) {
int DataSize = MyData.size();
Result += (char)( ( DataSize & 0xFF000000 ) >> 24 );
Result += (char)( ( DataSize & 0x00FF0000 ) >> 16 );
Result += (char)( ( DataSize & 0x0000FF00 ) >> 8 );
Result += (char)( DataSize & 0x000000FF );//Size Lead-In
Result += MyData;
}
return Result;
}
int NAL_Unit::Type( ) {
return ( MyData[0] & 0x1F );
}