Limitationsoftraditionalerrorresiliencemethods.pptVIP

Rane, Aaron, Girod - Systematic Lossy Forward Error Protection – VCIP 04, Jan 21, 2004 * * Department of Electrical Engineering, Stanford University Shantanu Rane, Anne Aaron and Bernd Girod Systematic Lossy Forward Error Protection for Error-Resilient Digital Video Broadcasting Limitations of traditional error-resilience methods FEC (“Cliff” effect) Layered Coding with Priority Encoding Transmission (PET) (Inferior R-D Performance) [Albanese et al., 1996] Outline Systematic source-channel coding framework Lossy Forward Error Protection using Wyner-Ziv coding Results and Conclusions Wyner-Ziv coding background encoder decoder X X’ Y Side-info at encoder and decoder: encoder decoder X X’ Y Side-info at decoder only: [Wyner and Ziv, 1975-76] Can achieve bit-rate savings due to correlation between X and Y Systematic 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] Lossy source-channel coding of video waveforms [Aaron, Rane and Girod, 2003] Wyner-Ziv Encoder Side info Digital Channel Analog Channel Wyner-Ziv Decoder 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* Systematic source-channel coding “Lossy” protection Fully backward compatible with legacy systems Side information ED T-1 Q-1 + MC S* T T-1 Q-1 Q MC EC Main Encoder - S + + Fallback Scheme for error-resilience Channel Fallback when errors occur T-1 q-1 ED + MC + + T T-1 q q-1 MC EC Fallback Encoder - Proposed Wyner-Ziv codec Channel Transmit only parity symbols Wyner-Ziv encoder ED T-1 Q-1 + MC S* Video Encoder main S Side information Video Encoder “coarse” T-1 q-1 ED + MC R-S Decoder Reconstructed frame at Encoder Video Encoder “coarse” R-