/// <summary>
/// Fills this subcode buffer with subchannel Q data. calculates the required CRC, as well.
/// Returns the crc, calculated or otherwise.
/// </summary>
public ushort Synthesize_SubchannelQ(ref SubchannelQ sq, bool calculateCRC)
{
int offset = 12; //Q subchannel begins after P, 12 bytes in
SubcodeDeinterleaved[offset + 0] = sq.q_status;
SubcodeDeinterleaved[offset + 1] = sq.q_tno;
SubcodeDeinterleaved[offset + 2] = sq.q_index;
SubcodeDeinterleaved[offset + 3] = sq.min.BCDValue;
SubcodeDeinterleaved[offset + 4] = sq.sec.BCDValue;
SubcodeDeinterleaved[offset + 5] = sq.frame.BCDValue;
SubcodeDeinterleaved[offset + 6] = sq.zero;
SubcodeDeinterleaved[offset + 7] = sq.ap_min.BCDValue;
SubcodeDeinterleaved[offset + 8] = sq.ap_sec.BCDValue;
SubcodeDeinterleaved[offset + 9] = sq.ap_frame.BCDValue;
ushort crc16;
if (calculateCRC)
{
crc16 = CRC16_CCITT.Calculate(SubcodeDeinterleaved, offset, 10);
}
else
{
crc16 = sq.q_crc;
}
//CRC is stored inverted and big endian
SubcodeDeinterleaved[offset + 10] = (byte)(~(crc16 >> 8));
SubcodeDeinterleaved[offset + 11] = (byte)(~(crc16));
return(crc16);
}
/// <summary>
/// Calculates the checksum of the provided Q subchannel buffer and emplaces it
/// </summary>
/// <param name="buffer">12 byte Q subchannel buffer: input and output buffer for operation</param>
/// <param name="offset">location within buffer of Q subchannel</param>
public static ushort SubQ_SynthChecksum(byte[] buf12, int offset)
{
ushort crc16 = CRC16_CCITT.Calculate(buf12, offset, 10);
//CRC is stored inverted and big endian
buf12[offset + 10] = (byte)(~(crc16 >> 8));
buf12[offset + 11] = (byte)(~(crc16));
return(crc16);
}
public void Read_SubchannelQ(byte[] buffer, int offset)
{
buffer[offset + 0] = q_status;
buffer[offset + 1] = q_tno.BCDValue;
buffer[offset + 2] = q_index.BCDValue;
buffer[offset + 3] = q_min.BCDValue;
buffer[offset + 4] = q_sec.BCDValue;
buffer[offset + 5] = q_frame.BCDValue;
buffer[offset + 6] = 0;
buffer[offset + 7] = q_amin.BCDValue;
buffer[offset + 8] = q_asec.BCDValue;
buffer[offset + 9] = q_aframe.BCDValue;
ushort crc16 = CRC16_CCITT.Calculate(buffer, 0, 10);
//CRC is stored inverted and big endian
buffer[offset + 10] = (byte)(~(crc16 >> 8));
buffer[offset + 11] = (byte)(~(crc16));
}
/// <summary>
/// Caclulates the checksum of the provided Q subchannel buffer
/// </summary>
public static ushort SubQ_CalcChecksum(byte[] buf12, int offset)
{
return(CRC16_CCITT.Calculate(buf12, offset, 10));
}
