Multi-hypothesis prediction extends motion compensation with one
prediction signal to the linear superposition of several motion-compensated
prediction signals with the result of increased coding efficiency.
The multiple hypotheses in this paper are blocks in past decoded frames.
These blocks are referenced by individual motion vectors and picture
reference parameters incorporating long-term memory motion-compensated
prediction. In this work, we at most employ two hypotheses similar to
B-frames. However, they are obtained from the past.
Due to the increased rate for the motion vectors, rate-constrained
coder control is utilized. On this basis, we demonstrate the efficiency
of multi-hypothesis prediction in combination with variable block size
and long-term memory and present bit-rate savings up to 32% when compared
to standard variable block size prediction without long-term memory motion
compensation.
|