Compressed video is very sensitive to channel errors. A few bit losses can stop the entire decoding process. Therefore, protecting compressed video is always necessary for reliable visual communications. In recent yea...
详细信息
ISBN:
(纸本)9780819469946
Compressed video is very sensitive to channel errors. A few bit losses can stop the entire decoding process. Therefore, protecting compressed video is always necessary for reliable visual communications. In recent years, Wyner-Ziv lossy coding has been used for error resilience and has achieved improvement over conventional techniques. In our previous work, we proposed an unequal error protection algorithm for protecting data elements in a video stream using a Wyner-Ziv codec. We also presented an improved method by adapting the parity data rates of protected video information to the video content. In this paper, we describe a feedback aided error resilience technique, based on Wyner-Ziv coding. By utilizing feedback regarding current channel packet-loss rates, a turbo coder can adaptively adjust the amount of parity bits needed for correcting corrupted slices at the decoder. This results in an efficient usage of the data rate budget for Wyner-Ziv coding while maintaining good quality decoded video when the data has been corrupted by transmission errors.
Compressed video is very sensitive to channel errors. A few bit losses can derail the entire decoding process. Thus, protecting compressed video is imperative to enable visual communications. Since different elements ...
详细信息
ISBN:
(纸本)9780819466211
Compressed video is very sensitive to channel errors. A few bit losses can derail the entire decoding process. Thus, protecting compressed video is imperative to enable visual communications. Since different elements in a compressed video stream vary in their impact on the quality of the decoded video, unequal error protection can be used to provide efficient protection. This paper describes an unequal error protection method for protecting data elements in a video stream, via a Wyner-Ziv encoder that consists of a coarse quantizer and a Turbo coder based lossless slepian-wolf encoder. Data elements that significantly impact the visual quality of decoded video, such as modes and motion vectors as used by H.264, are provided more parity bits than coarsely quantized transform coefficients. This results in an improvement in the quality of the decoded video when the transmitted sequence is corrupted by transmission errors, than obtained by the use of equal error protection.
暂无评论