Multimedia Processing:

1.1. A source emits letters from an alphabet A = {a₁,a₂,a₃} with probabilities P(a₁) = 1/2, P(a₂) = 1/4, P(a₃) = 1/4. Calculate the entropy of this source.

1.2. Assume we encode the message [c a b c], where our alphabet consists of the first 4 lower case letters of the English alphabet. Show Adaptive Huffman trees for coding and the Adaptive Huffman code for [c a b c].