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:  I mode Inter Inter4v Intra Skip

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

11. Rate-Distortion optimization (cont.) B(1, 1)B(2, 1)B(l, 1)B(L, 1) B(1, 2)B(2, 2)B(l, 2)B(L, 2) B(1, n)B(2, n)B(l, n)B(L, n) B(1, k 1 ) FEC B(2, k 2 ) B(l, k l ) B(L, k L ) Block 1 Block 2Block lBlock L Packet 1 Packet 2 Packet n Packet N N

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