ADAPTIVE VIDEO ENCODER FOR TWO-LAYER ENCODING OF VIDEO SIGNALS ON ATM (ASYNCHRONOUS TRANSFER MODE) NETWORKS

摘要

The quality of video images received at the remote end of an ATM network capable of transmitting data at high and low priorities is greatly improved at h igh cell loss levels by employing a two-layered video encoding technique that adapts the metho d for encoding information transmitted in the low-priority digital information stream to the rate of cell loss on the network so that compression efficiency and image quality are high when the network load is low and resiliency to cell loss is high when the network loa d is high. The encoder adapts its encoding method in response to a cell loss information si gnal generated by the remote decoder by selecting the prediction mode used to encode the low-priority digital information stream, and by changing the frequency at which slice-start synchronization codes are placed within the low-priority digital information str eam (FIG. 1).