1. Department of Electrical Engineering Stanford University Yi Liang, Eric Setton and Bernd Girod Channel-Adaptive Video Streaming Using Packet Path Diversity and Rate-Distortion Optimized Reference Picture Selection

2. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Motivation Channel-adaptive packet dependency control: Higher error-resilience; no packet retransmission Low-latency streaming (<1 second) for interactive applications [Liang, Flierl, Girod, ICIP’02] Path diversity Uncorrelated channel statistics Mitigate negative impact on data This work Low-latency streaming using multiple paths for further improvement R-D optimization for multiple streams 1 2 Data traffic Data traffic Content Server Client Relay Server Relay Server

3. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Outline Prior work Channel-adaptive reference picture selection Optimal packet dependency control for multiple streams Results and video demo

4. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Prior Schemes Video redundancy coding (VRC) [H.263++] Multiple state coding [Apostolopoulos] RPS-NACK [Lin et. al., ICME’01] 13 24 S S 028 13579 4610 NACK (1) ACK (7) Path 1 Path 2 Path 1 Path 2

5. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Dependency Control over Multiple Paths Path 1 Path 2 Long-Term Memory V=5 n-5 n-4 n-3 n-2 n-1 n Prediction modes: v =1, 2, … V, I V=1 V=2 V=3 V=5

6. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Path Selection Path selection: to minimize the distortion of next frame and take advantage of path diversity Alternate when both channels are good Send small probe packets over the channel in bad state

7. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Results (1) Channel loss_rate_1 =loss_rate_2 =15% LTM len=12 Avg burst len=8 Feedback delay=6

8. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Results (2) Channel loss_rate_1 =loss_rate_2 =15% LTM len=12 Avg burst len=8 Feedback delay=6

9. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Video Demo (1) Proposed schemeRPS-NACK Mother-Daughter 318 Kbps 20% loss

10. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Video Demo (2) Proposed schemeRPS-NACK Foreman 185 Kbps 20% loss

11. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Conclusions Eliminated the need for retransmission; low-latency (<1 second) streaming over multi-path Increased error-resilience by using Packet path diversity Feedback-based path selection Optimal packet dependency control Improved tradeoff between error-resilience (independent streams) and coding efficiency using R-D optimization

12. Liang, Setton and Girod: Packet Path Diversity and Rate-Distortion Optimized RPS Estimate of the Distortion q q p q p p … q p D 11, p 11 =q 3 D 12, p 12 =q 2 p D 18, p 18 =p 3 ………… P1 D 21, p 21 =q 2 pq pD 22, p 22 =up D 23, p 23 =up D 24, p 24 =p 2 P2 n-3 n-2 n-1 n