Page 226 - Video Coding for Mobile Communications Efficiency, Complexity, and Resilience

Part IV

Error Resilience

When transmitted over a mobile channel, compressed video can su er severe
degradation. Thus, error resilience is one of the main requirements for mobile
video communication.
This part contains two chapters. Chapter 9 reviews error-resilience video
coding techniques. The chapter considers the types of errors that can a ect a
video bitstream and examines their impact on decoded video. It then describes
a number of error detection and error control techniques. Particular emphasis
is given to standard error-resilience techniques included in the recent H.263+,
H.263++, and MPEG-4 standards.
Chapter 10 gives examples of the development of error-resilience tech-
niques. The chapter presents two temporal error concealment techniques. The
-rst technique, MFI, is based on motion -eld interpolation, whereas the second
technique, BM-MFI, uses multihypothesis motion compensation (MHMC) to
combine MFIwith a boundary matching (BM) technique. The techniques are
then tested within both an isolated test environment and an H.263 codec. The
chapter also investigates the performance of di erent temporal error conceal-
ment techniques when incorporated within a multiple-reference video codec.
In particular, the chapter -nds a combination of techniques, MFI-BM, that
best recovers the spatial-temporal components of a damaged multiple-reference
motion vector. In addition, the chapter develops a multihypothesis temporal
concealment technique, called MFI-MH, to be used with multiple-reference
systems.