C / C++ / MFC

int FindSequenceHeader(unsigned char *str)
{
	// Does a bit by bit search for the sequence header

	char ch[4];

	DWORD dwValue;

	for (int x = 0; x < 4; x++)
	{
		for (int i = 0; i < 8; i++)
		{
			ch[0] = ( (str[x + 0] << (0 + i)) | (str[x + 1] >> (8 - i)) );
			ch[1] = ( (str[x + 1] << (0 + i)) | (str[x + 2] >> (8 - i)) );
			ch[2] = ( (str[x + 2] << (0 + i)) | (str[x + 3] >> (8 - i)) );
			ch[3] = ( (str[x + 3] << (0 + i)) | (str[x + 4] >> (8 - i)) );

			dwValue = ( ch[0] | (ch[1] << 8) | (ch[2] << 16) | (ch[3] << 24) );

			switch (dwValue)
			{
				case 0x000001b3:
					cout << "Video Sequence Header Found" << endl;

					return 0;

					break;

				default:
	
					break;
			}
		}
	}

	// Found nothing...
	return 1;
}

DWORD MakeDword(unsigned char *str)
{
	return ( str[0] | (str[1] << 8) | (str[2] << 16) | (str[3] << 24) );
}