Parse code values:
Parse a Dirac sequence header.
The spec limits the number of wavelet decompositions to 4 for both level 1 (VC-2) and 128 (long-gop default). 5 decompositions is the maximum before >16-bit buffers are needed. Schroedinger allows this for DD 9,7 and 13,7 wavelets only, limiting the others to 4 decompositions (or 3 for the fidelity filter).