But at the same time, a compiler does a deterministic transformation of its inputs, and we still count its output as under copyright and license.
copyrighted input -> compiler -> copyrighted output
copyrighted input -> compiler -> copyrighted output
So portions of a derivative work are covered by the original copyright, and other portions may be under a distinct copyright as a derivative work, and several copyrights may apply to a work as a whole.
In the case of a Huffman transform, the transformed work does not meet the "creativity" requirements to be eligible for copyright, over that of the original works.