Wyner ziv coding

摘要

A system (100) for encoding an input video frame (1005), for transmitting or storing the encoded video and for decoding the video is disclosed. The system (100) includes an encoder (1000) and a decoder (1200) interconnected through a storage or transmission medium (1100). The encoder (1000) includes a turbo encoder (1015) for forming parity bit data from the input frame (1005) into a first data source (1120), and a sampler (1020) for down-sampling the input frame (1005) followed by intraframe compression (1030) to form a second data source (1110). The decoder (1200) receives data from the second data source (1110) to form an estimate for the frame (1005). The decoder (1200) also receivers the parity bit data from the first data source (1120), and corrects errors in the estimate by applying the parity bit data to the estimate. Each bit plane is corrected in turn by a turbo decoder (1260). The decoder determines how reliably a pixel value was decoded, too. Frame reconstruction module (1290) takes advantage of this and discards unreliably decoded pixels and replaces them with predicted pixel values.

主权项

1. A method of performing distributed video turbo decoding of an input video frame, the method comprising the steps of:
forming an estimate of the input video frame according to received key frame data; determining a reference pixel value, from the estimate of the input video frame, based upon a source pixel of the input video frame; determining a decoded pixel value based upon error correction information associated with the source pixel, the error correction information being applied to the estimate of the input video frame to determine the decoded pixel; determining that a bit of the decoded pixel value is not reliable if a log likelihood value of the bit, produced by the determining of the decoded pixel value based upon error correction information, is oscillating when compared with a previously produced log likelihood value of the bit; determining that the decoded pixel value is not reliable if the determined bit of the decoded pixel value is not reliable; and defining a value of an output pixel depending upon a reliability of the decoded pixel value, wherein if the decoded pixel value is reliable, the output pixel value is based upon the decoded pixel value, and if the decoded pixel value is not reliable, the output pixel value is based upon the reference pixel value.