/// <summary>
/// Encode an array of data codeword with GaloisField 256.
/// </summary>
/// <param name="dataBytes">Array of data codewords for a single block.</param>
/// <param name="numECBytes">Number of error correction codewords for data codewords</param>
/// <param name="generatorPoly">Cached or newly create GeneratorPolynomial</param>
/// <returns>Return error correction codewords array</returns>
internal static byte[] Encode(byte[] dataBytes, int numECBytes, GeneratorPolynomial generatorPoly)
{
int dataLength = dataBytes.Length;
if (generatorPoly is null)
{
throw new ArgumentNullException("generator", $"{nameof(GeneratorPolynomial)} var is null.");
}
if (dataLength == 0)
{
throw new ArgumentException("There is no data bytes to encode.");
}
if (numECBytes <= 0)
{
throw new ArgumentException("No Error Correction bytes.");
}
int[] toEncode = ConvertToIntArray(dataBytes, dataLength, numECBytes);
Polynomial generator = generatorPoly.GetGenerator(numECBytes);
Polynomial dataPoly = new Polynomial(generator.GField, toEncode);
PolyDivideStruct divideResult = dataPoly.Divide(generator);
int[] remainderCoeffs = divideResult.Remainder.Coefficients;
return(ConvertTosByteArray(remainderCoeffs, numECBytes));
}
/// <summary>
/// Encode an array of data codeword with GaloisField 256.
/// </summary>
/// <param name="dataBytes">Array of data codewords for a single block.</param>
/// <param name="numECBytes">Number of error correction codewords for data codewords</param>
/// <param name="generatorPoly">Cached or newly create GeneratorPolynomial</param>
/// <returns>Return error correction codewords array</returns>
internal static byte[] Encode(byte[] dataBytes, int numECBytes, GeneratorPolynomial generatorPoly)
{
int dataLength = dataBytes.Length;
if(generatorPoly == null)
throw new ArgumentNullException("generator", "GeneratorPolynomial var is null");
if(dataLength == 0)
throw new ArgumentException("There is no data bytes to encode");
if(numECBytes <= 0)
throw new ArgumentException("No Error Correction bytes");
int[] toEncode = ConvertToIntArray(dataBytes, dataLength, numECBytes);
Polynomial generator = generatorPoly.GetGenerator(numECBytes);
Polynomial dataPoly = new Polynomial(generator.GField, toEncode);
PolyDivideStruct divideResult = dataPoly.Divide(generator);
int[] remainderCoeffs = divideResult.Remainder.Coefficients;
return ConvertTosByteArray(remainderCoeffs, numECBytes);
}
public void PerformanceTest()
{
Random randomizer = new Random();
sbyte[] zxTestCase = PolynomialExtensions.GenerateSbyteArray(40, randomizer);
int ecBytes = 50;
byte[] testCase = PolynomialExtensions.ToByteArray(zxTestCase);
Stopwatch sw = new Stopwatch();
int timesofTest = 10000;
string[] timeElapsed = new string[2];
sw.Start();
GaloisField256 gf256 = GaloisField256.QRCodeGaloisField;
GeneratorPolynomial generator = new GeneratorPolynomial(gf256);
for(int i = 0; i < timesofTest; i++)
{
ReedSolomonEncoder.Encode(testCase, ecBytes, generator);
}
sw.Stop();
timeElapsed[0] = sw.ElapsedMilliseconds.ToString();
sw.Reset();
sw.Start();
for(int i = 0; i < timesofTest; i++)
{
EncoderInternal.generateECBytes(zxTestCase, ecBytes);
}
sw.Stop();
timeElapsed[1] = sw.ElapsedMilliseconds.ToString();
Assert.Pass("ReedSolomon performance {0} Tests~ QrCode.Net: {1} ZXing: {2}", timesofTest, timeElapsed[0], timeElapsed[1]);
}
/// <summary>
/// Generate error correction blocks. Then out put with codewords BitList
/// ISO/IEC 18004/2006 P45, 46. Chapter 6.6 Constructing final message codewords sequence.
/// </summary>
/// <param name="dataCodewords">Datacodewords from DataEncodation.DataEncode</param>
/// <param name="numTotalBytes">Total number of bytes</param>
/// <param name="numDataBytes">Number of data bytes</param>
/// <param name="numECBlocks">Number of Error Correction blocks</param>
/// <returns>codewords BitList contain datacodewords and ECCodewords</returns>
internal static BitList FillECCodewords(BitList dataCodewords, VersionDetail vd)
{
List<byte> dataCodewordsByte = dataCodewords.List;
int ecBlockGroup2 = vd.ECBlockGroup2;
int ecBlockGroup1 = vd.ECBlockGroup1;
int numDataBytesGroup1 = vd.NumDataBytesGroup1;
int numDataBytesGroup2 = vd.NumDataBytesGroup2;
int ecBytesPerBlock = vd.NumECBytesPerBlock;
int dataBytesOffset = 0;
byte[][] dByteJArray = new byte[vd.NumECBlocks][];
byte[][] ecByteJArray = new byte[vd.NumECBlocks][];
GaloisField256 gf256 = GaloisField256.QRCodeGaloisField;
GeneratorPolynomial generator = new GeneratorPolynomial(gf256);
for(int blockID = 0; blockID < vd.NumECBlocks; blockID++)
{
if(blockID < ecBlockGroup1)
{
dByteJArray[blockID] = new byte[numDataBytesGroup1];
for(int index = 0; index < numDataBytesGroup1; index++)
{
dByteJArray[blockID][index] = dataCodewordsByte[dataBytesOffset + index];
}
dataBytesOffset += numDataBytesGroup1;
}
else
{
dByteJArray[blockID] = new byte[numDataBytesGroup2];
for(int index = 0; index < numDataBytesGroup2; index++)
{
dByteJArray[blockID][index] = dataCodewordsByte[dataBytesOffset + index];
}
dataBytesOffset += numDataBytesGroup2;
}
ecByteJArray[blockID] = ReedSolomonEncoder.Encode(dByteJArray[blockID], ecBytesPerBlock, generator);
}
if(vd.NumDataBytes != dataBytesOffset)
throw new ArgumentException("Data bytes does not match offset");
BitList codewords = new BitList();
int maxDataLength = ecBlockGroup1 == vd.NumECBlocks ? numDataBytesGroup1 : numDataBytesGroup2;
for(int dataID = 0; dataID < maxDataLength; dataID++)
{
for(int blockID = 0; blockID < vd.NumECBlocks; blockID++)
{
if( !(dataID == numDataBytesGroup1 && blockID < ecBlockGroup1) )
codewords.Add((int)dByteJArray[blockID][dataID], 8);
}
}
for(int ECID = 0; ECID < ecBytesPerBlock; ECID++)
{
for(int blockID = 0; blockID < vd.NumECBlocks; blockID++)
{
codewords.Add((int)ecByteJArray[blockID][ECID], 8);
}
}
if( vd.NumTotalBytes != codewords.Count >> 3)
throw new ArgumentException(string.Format("total bytes: {0}, actual bits: {1}", vd.NumTotalBytes, codewords.Count));
return codewords;
}