Universal Reed-Solomon Codec

A .NET implementation of the Reed-Solomon algorithm, supporting error, erasure and errata correction.

Uses code from the Reed-Solomon component of the ZXing.Net project and code I've ported to C#, from the python code at Wikiversity.

Code examples

Create a representation of a Galois field:

GenericGF field = new GenericGF(285, 256, 0);

Reed-Solomon encoding:

Create an instance of the ReedSolomonEncoder class, specifying the Galois field to use:

ReedSolomonEncoder rse = new ReedSolomonEncoder(field);

To encode the string "Hello World" with 9 ecc symbols, 9 null-values must be appended to store the ecc symbols:

int[] data = new int[] { 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x57, 0x6F, 0x72, 0x6C, 0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

Call the Encode() method of the ReedSolomonEncoder class to encode data with Reed-Solomon:

rse.Encode(data, 9);

The data variable now contains:

0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x57, 0x6F, 0x72, 0x6C, 0x64, 0x40, 0x86, 0x08, 0xD5, 0x2C, 0xAE, 0xB5, 0x8F, 0x83

Reed-Solomon decoding:

Previous data variable with some errors:

data = new int[] { 0x00, 0x02, 0x02, 0x02, 0x02, 0x02, 0x57, 0x6F, 0x72, 0x6C, 0x64, 0x40, 0x86, 0x08, 0xD5, 0x2C, 0xAE, 0xB5, 0x8F, 0x83 };

Providing the locations of some erasures:

int[] erasures = new int[] { 0, 1, 2 };

Create an instance of the ReedSolomonDecoder class, specifying the Galois field to use:

ReedSolomonDecoder rsd = new ReedSolomonDecoder(field);

Call the Decode() method of the ReedSolomonDecoder class to decode (correct) data with Reed-Solomon:

if (rsd.Decode(data, 9, erasures))
{
    // Data corrected.
}
else
{
    // Too many errors/erasures to correct.
}

The data variable now contains:

0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x57, 0x6F, 0x72, 0x6C, 0x64, 0x40, 0x86, 0x08, 0xD5, 0x2C, 0xAE, 0xB5, 0x8F, 0x83

License

This project uses source files which are under Apache License 2.0, thus this repository is also under this license.