/// <summary>
/// Decodes the codewords.
/// </summary>
/// <returns>The codewords.</returns>
/// <param name="codewords">Codewords.</param>
/// <param name="ecLevel">Ec level.</param>
/// <param name="erasures">Erasures.</param>
private static DecoderResult decodeCodewords(int[] codewords, int ecLevel, int[] erasures)
{
if (codewords.Length == 0)
{
return(null);
}
int numECCodewords = 1 << (ecLevel + 1);
int correctedErrorsCount = correctErrors(codewords, erasures, numECCodewords);
if (correctedErrorsCount < 0)
{
return(null);
}
if (!verifyCodewordCount(codewords, numECCodewords))
{
return(null);
}
// Decode the codewords
DecoderResult decoderResult = DecodedBitStreamParser.decode(codewords, ecLevel.ToString());
if (decoderResult != null)
{
decoderResult.ErrorsCorrected = correctedErrorsCount;
decoderResult.Erasures = erasures.Length;
}
return(decoderResult);
}
/// <summary>
/// <p>Decodes a PDF417 Code represented as a <see cref="BitMatrix" />.
/// A 1 or "true" is taken to mean a black module.</p>
///
/// <param name="bits">booleans representing white/black PDF417 Code modules</param>
/// <returns>text and bytes encoded within the PDF417 Code</returns>
/// <exception cref="FormatException">if the PDF417 Code cannot be decoded</exception>
/// </summary>
public DecoderResult decode(BitMatrix bits)
{
// Construct a parser to read the data codewords and error-correction level
BitMatrixParser parser = new BitMatrixParser(bits);
int[] codewords = parser.readCodewords();
if (codewords == null || codewords.Length == 0)
{
return(null);
}
int ecLevel = parser.getECLevel();
int numECCodewords = 1 << (ecLevel + 1);
int[] erasures = parser.getErasures();
if (!correctErrors(codewords, erasures, numECCodewords))
{
return(null);
}
if (!verifyCodewordCount(codewords, numECCodewords))
{
return(null);
}
// Decode the codewords
return(DecodedBitStreamParser.decode(codewords));
}
/// <summary>
/// Decodes the codewords.
/// </summary>
/// <returns>The codewords.</returns>
/// <param name="codewords">Codewords.</param>
/// <param name="ecLevel">Ec level.</param>
/// <param name="erasures">Erasures.</param>
private static DecoderResult DecodeCodewords(int[] codewords, int ecLevel, int[] erasures)
{
if (codewords.Length == 0)
{
throw ReaderException.Instance;
}
int numECCodewords = 1 << (ecLevel + 1);
Log.WriteLine("EC level: " + ecLevel + ", ec codewords: " + numECCodewords);
int correctedErrorsCount = CorrectErrors(codewords, erasures, numECCodewords);
Log.WriteLine("Corrected errors: " + correctedErrorsCount);
VerifyCodewordCount(codewords, numECCodewords);
// Decode the codewords
DecoderResult decoderResult = DecodedBitStreamParser.Decode(codewords);
decoderResult.ErrorsCorrected = (correctedErrorsCount >= 0) ? correctedErrorsCount : 0;
decoderResult.Erasures = erasures.Length;
return(decoderResult);
}
