1. 1 Department of Electrical Engineering, Stanford University Anne Aaron, Shantanu Rane, David Rebollo-Monedero and Bernd Girod Systematic Lossy Forward Error Protection for Video Waveforms

2. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 2 Overview  Error Resilient Digital Video Broadcasting  Systematic Lossy Forward Error Protection  Embedded Wyner-Ziv Coding  Improved Wyner-Ziv Video Codec

3. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 3 Error-Resilient Digital Video Broadcasting Terrestrial broadcast Cable TV Satellite Broadcast uplink Forward Error Correction (FEC)  “Cliff” effect  For graceful degradation, Priority Encoding Transmission (PET) [Albanese, et al., 1996]  Layered representation incurs a rate-distortion penalty Forward Error Protection (FEP)  Protects the video waveform  Graceful degradation without layered representation

4. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 4 Encoder Related Work Channel A DecoderChannel D X X*X* Y Bounds for systematic lossy source-channel coding [Shamai, Verdu and Zamir, 1998] Enhancing analog transmission systems using digital side information [Pradhan and Ramchandran, 2001] Robust predictive coding [Sehgal and Ahuja, 2003] Side information uncoded

5. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 5 S*S* Reconstruction Slepian- Wolf Encoder Slepian- Wolf Decoder Side information Coarse Quantizer Scalar Quantizer Turbo Encoder Turbo Decoder Systematic Lossy Forward Error Protection MPEG Encoder MPEG Decoder with Error Concealment Error-Prone channel S S’  Protects the original video waveform  “Lossy” protection Wyner-Ziv Decoder Wyner-Ziv Encoder

6. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 6 Results Carphone: CIF, 50 frames @ 30fps 1 Mbps, 1% macroblock loss

7. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 7 Error Concealment only (No WZ bits) Wyner-Ziv Coding (16 quantization levels, 0.75bpp) Carphone: CIF, 1 Mbps, 1% macroblock loss

8. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 8 Embedded Wyner-Ziv Codec MPEG Encoder MPEG Decoder with Error Concealment Error-Prone channel S S’ S*S* Wyner-Ziv Encoder A Wyner-Ziv Decoder A S ** Wyner-Ziv Encoder B Wyner-Ziv Decoder B Graceful degradation of video quality Does not require layered representation … …

9. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 9 Results 2-level Wyner-Ziv Codec Carphone: CIF, 50 frames @ 30fps 1 Mbps, 1% macroblock loss

10. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 10 Systematic Lossy Forward Error Protection MPEG Encoder MPEG Decoder with Error Concealment Error-Prone channel S S’ Wyner-Ziv Decoder Coarse Quantizer Wyner-Ziv Encoder Reconstruction Slepian- Wolf Encoder Slepian- Wolf Decoder S*S*

11. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 11 Improved Wyner-Ziv Coder Error-Prone channel MPEG Encoder MPEG Decoder with Error Concealment S S’ MPEG Encoder Common reference frame MPEG Encoder [Rane, Aaron, Girod (submitted to VCIP ’04)] Parity symbols R-S Encoder R-S Decoder Side information S*S* Wyner-Ziv Encoder Wyner-Ziv Decoder MPEG Decoder Common reference frame Fallback to coarse representation

12. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 12 Systematic Lossy FEP vs. FEC Foreman.cif FEC Main Stream @ 1.092 Mbps FEC (n,k) = (40,36) FEC bitrate = 120 Kbps Total = 1.2 Mbps Proposed Scheme Main Stream @ 1.092 Mbps WZ Stream @ 270 Kbps FEP (n,k) = (52,36) WZ bitrate = 120 Kbps Total = 1.2 Mbps

13. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 13 1 Mbps + 120 kbps FEC (33.03 db) Foreman: CIF, 50 frames, symbol error rate = 10 -3 1 Mbps + 120 kbps FEP (38.40 db)

14. Aaron, Rane, Rebollo-Monedero, Girod: Forward Error Protection of Video Sept. 15, 2003 14 Summary A novel systematic lossy forward error protection scheme for error-resilient video broadcasting Wyner-Ziv coding applied to forward error protection Advantages  More robust than FEC over a wide range of error rates  Graceful degradation without layered video representation  Backward-compatible