The Hong Kong University of Science and Technology

Kiu Sha Management Limited Liability Company

Choy Sai Foundation L.l.c.

Xiaopeng Fan

Oscar Chi Lim Au

Described herein is a novel transcoding technique called lossless inter frame transcoding (LIFT) for improving the error resilience of video streaming. According to various embodiments, conventional coded blocks are selectively transcoded into new transcoded blocks. At the decoder, the transcoded blocks can be transcoded back to the conventional coded blocks when prediction is available and can also be robustly decoded independently when prediction is unavailable. According to another embodiment, an offline transcoding and online composing technique is provided for generating a composite frame using the transcoded and conventional coded blocks and adjusting the ratio of the transcoded blocks, thereby achieving error robustness scalability.

Method and system for transcoding based robust streaming of compressed video

Efficient encoding and/or decoding of digital video is provided using multiple candidate reference frames, making playback of the digital video optionally reversible. For example, a source can be encoded as duplex coded frames having multiple candidate reference frames. The reference frames can be previous or future frames, and the duplex coded frames can be encoded at a bit-rate that ensures lossless decoding using any of the candidate reference frames. Therefore, the duplex coded frames can encoded in normal and/or reverse temporal order. In this regard, the ability to decode digital video frames using either a single previous or future frame enables reversible digital video, bit-stream switching and video splicing arbitrary time points, and provides for increased error resilience.

Flexible Wyner-Ziv video frame coding

Systems and methodologies for employing bidirectionally decodable Wyner-Ziv video coding (BDWZVC) are described herein. BDWZVC can be used to generate M-frames, which have multiple reference frames at an encoder and can be forward and backward decodable. For example, optimal Lagrangian multipliers for forward and backward motion estimation can be derived and/or utilized. The optimal Lagrangian multiplier for backward motion estimation can be approximately twice as large as the optimal Lagrangian multiplier for forward motion estimation. Further, an optimal P-frame/M-frame selection scheme can be employed to enhance rate-distortion performance when video is transmitted over an error prone channel. Accordingly, a first frame in a group of pictures (GOP) can be encoded as an I-frame, a next m&#x2212;1 frames can be encoded as P-frames, and a remaining n&#x2212;m frames can be encoded as M-frames, where n can be a length of the GOP and m can be optimally identified.

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Hong Kong, China

Xiaopeng Fan