The deepest max_depth this reader supports, though the format allows
up to 26: every code is then below 4^16 = 2^32, so a decoded chunk
holds its codes in 32 bits. Deeper files aren't worth reading in
place: one chunk is one zlib block that a lookup inflates whole, and
at depth 16 a chunk already spans up to 4^16 cells, so a lookup could
inflate gigabytes. Finer cells should come from a bigger chunk grid
(width_exp, height_exp) instead (binary-format.md Section 10).
The deepest
max_depththis reader supports, though the format allows up to 26: every code is then below 4^16 = 2^32, so a decoded chunk holds its codes in 32 bits. Deeper files aren't worth reading in place: one chunk is one zlib block that a lookup inflates whole, and at depth 16 a chunk already spans up to 4^16 cells, so a lookup could inflate gigabytes. Finer cells should come from a bigger chunk grid (width_exp,height_exp) instead (binary-format.md Section 10).