Error Resilience and Concealment Techniques for Packet Video Transmission

PhD Thesis Proposal Defence


Title: "Error Resilience and Concealment Techniques for Packet Video Transmission"

by

Miss Mengyao Ma


Abstract:

Since the quality of compressed video is vulnerable to errors, video 
transmission over unreliable Internet is very challenging today. In this 
proposal, two important issues about robust packet video transmission are 
investigated.

The first issue is error resilient video compression. Motivated by 
two-hypothesis motion-compensated prediction (THMCP), we first propose an error 
resilient video coding technique, where two-hypothesis and one-hypothesis 
predictions are alternately used to encode the video stream. We use some 
schemes to determine which kind of prediction should be used, so that in some 
cases of frame losses, the propagated error can be first decreased to some 
extent before it spreads to the subsequent frames. Then we extend the previous 
work for THMCP to a more generalized one, i.e. the reference frames can be some 
distance from the current frame, instead of only the immediately preceding 
ones. Three types of prediction patterns are proposed and implemented by the 
generalized B pictures in H.264/AVC. In the case of a single frame loss during 
the transmission, the induced error propagation is analyzed and the closed-form 
expression for error energy is derived.

The second issue is error concealment for frame losses in video transmission. 
We first propose an error concealment algorithm to reconstruct a lost frame in 
the odd/even temporal sub-sampling MDC. The neighboring frames in the 
error-free stream are used to temporally interpolate the lost frame, based the 
preserved motion vector in this correct stream. To further improve the 
reconstructed video quality after the lost one, we also propose a 
multi-hypothesis error concealment (MHC) algorithm. In addition to 
error-concealing the lost frame, MHC also applies temporal interpolation to 
some additional frames after the frame loss so as to reduce propagated error 
quickly. Finally, we propose two error concealment algorithms for INTRA-frame 
losses over packet loss channels. The novelty is that not only the INTRA-frame 
but also the subsequent INTER-frames are error concealed based on the strong 
correlation between adjacent pixel values. In addition, motion compensation is 
used to reconstruct the INTER-pixel which has an INTRA-pixel in its motion 
trajectory.


Date:     		Monday, 22 September 2008

Time:                   10:00a.m.-12:00noon

Venue:                  Room 3501
 			lifts 25-26

Committee Members:	Dr. Gary Chan (Supervisor)
 			Dr. Oscar Au (Supervisor, ECE)
 			Dr. Albert Chung (Chairperson)
                         Dr. David Rossiter
 			Dr. Pedro Sander


**** ALL are Welcome ****