Transmission of Low-Bit-Rate MPEG-4 Video Signals Over Wireless Channels

摘要

The objective of this thesis is to study the performance of the MPEG- 4 video coding standard in the presence of highly erroneous media, such as a wireless channel, MPEG-4 treats video sequences as a collection of objects rather than a collection of frames. A Matlab encoder that confirms to this approach is built for compressing raw video signals at various compression rates, A two-state Markov channel was used to simulate a wireless channel that introduces errors in the video bitstream and a decoder that utilizes error concealment techniques to hide these errors from the user was used to reconstruct the video sequence, The error resilient tools that the MPEG-4 standard provides to enhance the robustness in the presence of errors were simulated and proven to be advantageous compared to methods used in previous standards (MPEG-2, H,263, etc,) At the decoder, the use of error concealment techniques significantly enhanced the quality of the reconstructed video in high bit error rate environments.