# Codage prioritaire et application a la transmission

##
Kave Salamatian

### Universite Paris SUD, ORSAY

### Résumé:

In this presentation we will apply information theory and joint
source/channel coding concepts to the transmission of
multimedia flows over INTERNET packet lossy channels. We derive the minimal
achievable mean distortion at the
receiver side for memoryless erasure channels and shows that for interactive
realtime applications where the code
length are bounded, we cannot achieve the distortion level predicted by the
separation principle in information theory.
The probability of large deviation of the observed distortion at receiver
side is another studied performance criteria.
We show that hierarchical source coding combined with Priority encoding
channel coding schemes can bound the
probability of large deviation from the mean distortion at the price of a
slightly lower minimal mean distortion rate.