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Added static CCITT-CRC16 lookup table.

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Subchannel Q is big-endian.
	Detect if a CD-Text pack is really a CD-Text pack to not
	confuse with CD+G packs.
	An audio disc can have subchannel correct but channel null.
	Viceversa can happen. Those should be considered correct and
	not unknown.
This commit is contained in:
Natalia Portillo
2014-08-25 17:20:05 +01:00
parent 3a03e3121e
commit 168b22f869
1 changed files with 112 additions and 57 deletions
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169
DiscImageChef/Checksums/CDChecksums.cs
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@@ -61,15 +61,20 @@ namespace DiscImageChef.Checksums
bool? channelStatus = CheckCDSectorChannel(channel);
bool? subchannelStatus = CheckCDSectorSubChannel(subchannel);
bool? status = null;
if (channelStatus == null || subchannelStatus == null)
return null;
if (channelStatus == null && subchannelStatus == null)
status = null;
if (channelStatus == false || subchannelStatus == false)
return false;
status = false;
if (channelStatus == null && subchannelStatus == true)
status = true;
if (channelStatus == true && subchannelStatus == null)
status = true;
if (channelStatus == true && subchannelStatus == true)
return true;
status = true;
return null;
return status;
}
case 2352:
return CheckCDSectorChannel(buffer);
@@ -421,80 +426,130 @@ namespace DiscImageChef.Checksums
CDTextPack4[j] = (byte)(CDTextPack4[j] | (subchannel[i++] & 0x3F));
}
UInt16 QSubChannelCRC = BitConverter.ToUInt16(QSubChannel, 10);
BigEndianBitConverter.IsLittleEndian = true;
UInt16 QSubChannelCRC = BigEndianBitConverter.ToUInt16(QSubChannel, 10);
byte[] QSubChannelForCRC = new byte[10];
Array.Copy(QSubChannel, 0, QSubChannelForCRC, 0, 10);
byte[] CalculatedQCRCBytes = new byte[2];
CRC16Context.Data(QSubChannelForCRC, out CalculatedQCRCBytes);
UInt16 CalculatedQCRC = BitConverter.ToUInt16(CalculatedQCRCBytes, 0);
UInt16 CalculatedQCRC = CalculateCCITT_CRC16(QSubChannelForCRC);
if (QSubChannelCRC != CalculatedQCRC)
{
if (MainClass.isDebug)
// Console.WriteLine("DEBUG (CDChecksums): Q subchannel CRC 0x{0:X4}, expected 0x{1:X4}", CalculatedQCRC, QSubChannelCRC);
Console.WriteLine("DEBUG (CDChecksums): Q subchannel CRC 0x{0:X4}, expected 0x{1:X4}", CalculatedQCRC, QSubChannelCRC);
status = false;
}
UInt16 CDTextPack1CRC = BitConverter.ToUInt16(CDTextPack1, 16);
byte[] CDTextPack1ForCRC = new byte[16];
Array.Copy(CDTextPack1, 0, CDTextPack1ForCRC, 0, 16);
byte[] CalculatedCDTP1CRCBytes = new byte[2];
CRC16Context.Data(CDTextPack1ForCRC, out CalculatedCDTP1CRCBytes);
UInt16 CalculatedCDTP1CRC = BitConverter.ToUInt16(CalculatedCDTP1CRCBytes, 0);
if (CDTextPack1CRC != CalculatedCDTP1CRC && CDTextPack1CRC != 0)
if ((CDTextPack1[0] & 0x80) == 0x80)
{
if (MainClass.isDebug)
// Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 1 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack1CRC, CalculatedCDTP1CRC);
UInt16 CDTextPack1CRC = BigEndianBitConverter.ToUInt16(CDTextPack1, 16);
byte[] CDTextPack1ForCRC = new byte[16];
Array.Copy(CDTextPack1, 0, CDTextPack1ForCRC, 0, 16);
UInt16 CalculatedCDTP1CRC = CalculateCCITT_CRC16(CDTextPack1ForCRC);
if (CDTextPack1CRC != CalculatedCDTP1CRC && CDTextPack1CRC != 0)
{
if (MainClass.isDebug)
Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 1 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack1CRC, CalculatedCDTP1CRC);
status = false;
}
}
UInt16 CDTextPack2CRC = BitConverter.ToUInt16(CDTextPack2, 16);
byte[] CDTextPack2ForCRC = new byte[16];
Array.Copy(CDTextPack2, 0, CDTextPack2ForCRC, 0, 16);
byte[] CalculatedCDTP2CRCBytes = new byte[2];
CRC16Context.Data(CDTextPack2ForCRC, out CalculatedCDTP2CRCBytes);
UInt16 CalculatedCDTP2CRC = BitConverter.ToUInt16(CalculatedCDTP2CRCBytes, 0);
if (CDTextPack2CRC != CalculatedCDTP2CRC && CDTextPack2CRC != 0)
if ((CDTextPack2[0] & 0x80) == 0x80)
{
if (MainClass.isDebug)
// Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 2 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack2CRC, CalculatedCDTP2CRC);
status = false;
UInt16 CDTextPack2CRC = BigEndianBitConverter.ToUInt16(CDTextPack2, 16);
byte[] CDTextPack2ForCRC = new byte[16];
Array.Copy(CDTextPack2, 0, CDTextPack2ForCRC, 0, 16);
UInt16 CalculatedCDTP2CRC = CalculateCCITT_CRC16(CDTextPack2ForCRC);
Console.WriteLine("Cyclic CDTP2 0x{0:X4}, Calc CDTP2 0x{1:X4}", CDTextPack2CRC, CalculatedCDTP2CRC);
if (CDTextPack2CRC != CalculatedCDTP2CRC && CDTextPack2CRC != 0)
{
if (MainClass.isDebug)
Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 2 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack2CRC, CalculatedCDTP2CRC);
status = false;
}
}
UInt16 CDTextPack3CRC = BitConverter.ToUInt16(CDTextPack3, 16);
byte[] CDTextPack3ForCRC = new byte[16];
Array.Copy(CDTextPack3, 0, CDTextPack3ForCRC, 0, 16);
byte[] CalculatedCDTP3CRCBytes = new byte[2];
CRC16Context.Data(CDTextPack3ForCRC, out CalculatedCDTP3CRCBytes);
UInt16 CalculatedCDTP3CRC = BitConverter.ToUInt16(CalculatedCDTP3CRCBytes, 0);
if (CDTextPack3CRC != CalculatedCDTP3CRC && CDTextPack3CRC != 0)
if ((CDTextPack3[0] & 0x80) == 0x80)
{
if (MainClass.isDebug)
// Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 3 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack3CRC, CalculatedCDTP3CRC);
status = false;
UInt16 CDTextPack3CRC = BigEndianBitConverter.ToUInt16(CDTextPack3, 16);
byte[] CDTextPack3ForCRC = new byte[16];
Array.Copy(CDTextPack3, 0, CDTextPack3ForCRC, 0, 16);
UInt16 CalculatedCDTP3CRC = CalculateCCITT_CRC16(CDTextPack3ForCRC);
Console.WriteLine("Cyclic CDTP3 0x{0:X4}, Calc CDTP3 0x{1:X4}", CDTextPack3CRC, CalculatedCDTP3CRC);
if (CDTextPack3CRC != CalculatedCDTP3CRC && CDTextPack3CRC != 0)
{
if (MainClass.isDebug)
Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 3 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack3CRC, CalculatedCDTP3CRC);
status = false;
}
}
UInt16 CDTextPack4CRC = BitConverter.ToUInt16(CDTextPack4, 16);
byte[] CDTextPack4ForCRC = new byte[16];
Array.Copy(CDTextPack4, 0, CDTextPack4ForCRC, 0, 16);
byte[] CalculatedCDTP4CRCBytes = new byte[2];
CRC16Context.Data(CDTextPack4ForCRC, out CalculatedCDTP4CRCBytes);
UInt16 CalculatedCDTP4CRC = BitConverter.ToUInt16(CalculatedCDTP4CRCBytes, 0);
if (CDTextPack4CRC != CalculatedCDTP4CRC && CDTextPack4CRC != 0)
if ((CDTextPack4[0] & 0x80) == 0x80)
{
if (MainClass.isDebug)
// Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 4 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack4CRC, CalculatedCDTP4CRC);
status = false;
UInt16 CDTextPack4CRC = BigEndianBitConverter.ToUInt16(CDTextPack4, 16);
byte[] CDTextPack4ForCRC = new byte[16];
Array.Copy(CDTextPack4, 0, CDTextPack4ForCRC, 0, 16);
UInt16 CalculatedCDTP4CRC = CalculateCCITT_CRC16(CDTextPack4ForCRC);
Console.WriteLine("Cyclic CDTP4 0x{0:X4}, Calc CDTP4 0x{1:X4}", CDTextPack4CRC, CalculatedCDTP4CRC);
if (CDTextPack4CRC != CalculatedCDTP4CRC && CDTextPack4CRC != 0)
{
if (MainClass.isDebug)
Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 4 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack4CRC, CalculatedCDTP4CRC);
status = false;
}
}
// return status;
// TODO: Correct CRC poly and seed
// TODO: Detect CD-Text vs CD+G packets
return null;
return status;
}
static readonly ushort[] CCITT_CRC16Table = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
};
static ushort CalculateCCITT_CRC16(byte[] buffer)
{
UInt16 CRC16=0;
for (int i = 0; i < buffer.Length; i++) {
CRC16 = (ushort)(CCITT_CRC16Table[(CRC16 >> 8) ^ buffer[i]] ^ (CRC16 << 8));
}
CRC16 = (ushort)~CRC16;
return CRC16;
}
}
}