anchor.diff:                  let index = (byte leadingZeros <<< 4) ||| byte dc
                   let huff = coder.acLumInv.[int index]
                   x.Write huff
  -                x.Write(Codeword(byte dc, v))
  +                x.Write(Codeword.Create(dc, v))
   
                   
               member x.WriteDCChrom(v : int) =
  
positive.code:                 let index = (byte leadingZeros <<< 4) ||| byte dc
                  let huff = coder.acChromaInv.[int index]
                  x.Write huff
                  x.Write(Codeword(byte dc, v))
  
          let writeBlock (bs : BitStream) (block : V3i[]) =
  
  
negative.code:                 counts : int[]
                  values : byte[]
              }
  
          type HuffmanSpec =
              {
                  specDCLum : TableSpec
  