Error Resilience of Video Transmission By Rate-Distortion Optimization and Adaptive Packetization

1. Error Resilience of Video Transmission By Rate-Distortion Optimization and Adaptive Packetization Yuxin Liu, Paul Salama and Edwad Delp ICME 2002

2. Outline • Introduction • Error resilience in H.263+ • Rate-distortion optimization • Proposed Scheme • Adaptive Packetization • Two-layer rate-distortion optimization • Experimental Result • Conclusion

3. Introduction • Packet loss • Quality degradation • Error propagation • Error Resilience • coding efficiency

4. Error Resilience in H.263+ • 20 negotiable coding option • Annex A to Annex T • Improve coding efficiency and capabilities • About Error Resilience • Annex K: Slice Structure • Annex R: Independent Segment • Annex N: Reference Picture Selection

5. Annex K in H.263+ • Slice Structure mode • a video picture segment • replace GOB layer, more flexiable • Every MB belongs to one and only one slice in the same frame • Two submode • Rectangular Slice submode • Arbitrary Slice Ordering submode

6. Annex K in H.263+ (cont.) • Allow slice header to act as resynchronization points • No data dependencies can cross the slice boundary • Motion vector prediction • Overlapped block motion compensation (OBMC) • Advanced INTRA coding mode • Not prevent ME across boundary

7. Annex K in H.263+ (cont.) • Motion prediction

8. Annex R in H.263+ • Independent Segment Decoding mode • To decode without other segment • If Annex K is in use, each slice forms a independent segment • Spatial error propagation and temporal error progation

9. Rate-Distortion optimization • Legrange multipliers: • Imode • Inter • Inter4v • Intra • Skip

10. Rate-Distortion optimization (cont.) • Distortion • Quantization Error • Packet Loss • Error Resilience by FEC coding • across packet

11. Block 1 Block 2 Block l Block L Packet 1 B(1, 1) B(2, 1) B(l, 1) B(L, 1) Packet 2 B(1, 2) B(2, 2) B(l, 2) B(L, 2) Packet n B(1, n) B(2, n) B(l, n) B(L, n) B(1, k1) N FEC B(2, k2) FEC FEC B(l, kl) FEC FEC FEC B(L, kL) Packet N FEC FEC FEC FEC Rate-Distortion optimization (cont.)

12. Proposed Scheme • The independency of ISD is in decoder view • propose a new packetization scheme • No dependency across boundary • propose two-layer rate-distortion optimization

13. Adaptive Packetization • Obey following 5 principles: • No dependency across the GOBs • Motion prediction, OBMC, advanced INTRA block prediction • GOB is packeted with it’s reference GOBs • If a GOB can’t fit into packet with it’s reference GOBs, the GOB is encoded in INTRA mode and is packeted into a new packet.

14. Adaptive Packetization (cont.) • The number of GOBs in one packet depends on the maximan size of packet • Each GOB can be reference at most once for motion estimation • Every packet contains at least one GOB which is INTRA mode

15. Adaptive Packetization (cont.) Reference picture current picture packet

16. Two-layer R-D optimization • First-layer RD optimization • Determine the optimal coding mode Searching range

17. Two-layer R-D optimization (cont.) • Second-layer R-D optimization • Choice the final GOB of all possible GOBs

18. Experimental Result

19. Experimental Result (cont.)

20. Conclusion • Adaptive packetization and two-layer R-D optimization is proposed • Use annexes of H.263+ to do error resilience