リードソロモン符号を用いた符号化

gistfile1.scala

object RSEncoder {
  def encode(raw_code: Array[Int]) = {
    val gf = GaloisField.a8

    val g_index = Array(
      43, 139, 206, 78, 43, 239, 123, 206, 214,
      147, 24, 99, 150, 39, 243, 163, 136
    )

    val code =
      Array.fill(math.max(raw_code.length, g_index.length) + 1)(0)

    for(i <- 0 until raw_code.length)
      code(i) = raw_code(i)

    for (_ <- 0 until raw_code.length) {
      if (code(0) != 0) {
        val div = gf.root(code(0))
        for (i <- 0 until code.length - 1) {
          code(i) =
            if (i < g_index.length) code(i + 1) ^ gf.pow((g_index(i) + div) % 255)
            else code(i + 1)
        }
      } else {
        for(i <- 0 until code.length - 1) code(i) = code(i + 1)
      }
    }

    for (i <- 0 until g_index.length)
      print(code(i) + " ")
  }

  def test = {
    val raw_code = Array(32, 65, 205, 69, 41, 220, 46, 128, 236)
    encode(raw_code)
  }
}