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Distributed video coding with feedback channel constraints This publication appears in: IEEE Transactions on Circuits and Systems for Video Technology Authors: J. Slowack, J. Skorupa, N. Deligiannis, P. Lambert, A. Munteanu and R. Van De Walle Volume: 22 Issue: July 2012 Pages: 1014-1026 Publication Date: Jul. 2012
Abstract: Many of the Distributed Video Coding (DVC) systems described in the literature make use of a feedback channel from the decoder to the encoder to determine the rate. However, the number of requests through the feedback channel is often high, and as a result the overall delay of the system could be unacceptable in practical applications. As a solution, feedback free DVC systems have been proposed, but the problem with these solutions is that they incorporate a difficult trade-off between encoder complexity and compression performance. Recognizing that a limited form of feedback may be supported in many video streaming scenarios, in this paper we propose a method for constraining the number of feedback requests to a fixed maximum number of N requests for an entire Wyner-Ziv (WZ) frame. The proposed technique estimates the WZ rate at the decoder using information obtained from previously decoded WZ frames, and defines the N requests by minimizing the expected rate overhead. Tests on eight sequences show that
the rate penalty is less than 5% when only 5 requests are allowed per WZ frame (for a GOP of size four). Furthermore, due to improvements from previous work, the system is able to perform better than or similar to DISCOVER even when up to 2 requests per WZ frame are allowed. The practical usefulness of the proposed approach is studied by estimating end-to-end delay and encoder buffer requirements, indicating that DVC with constrained feedback can be an important solution in the context of video streaming scenarios. External Link.
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