Two main disadvantages of Huffman encoding is that it makes two passes over data:
- First pass: Find out sequences frequencies $f(\cdot)$ of letters $c \in C$ in the document $D$. Then constructing Huffman optimal tree before transmitting the tree to the receiver.
- Second pass: encode and transmit the letters themselves based on tree structure.
Problem: Why we don't just transmit Huffman Tree over network to the receiver please? Why we need the second pass?