Our previous work in the corruption model is extended in this research to cover a more general error propagation scenario, and then used to develop a joint AIR/UEP (adaptive intra-refresh/unequal error protection) scheme. Basically, we relate AIR to the importance of packets via the corruption model at the encoder. Once the intra refresh ratio is determined, which is currently assumed to be known either by a priori knowledge or the network feedback, the expected distortion for each macroblock is calculated based on the corruption model and AIR is performed accordingly. The corruption model exploits the initial error strength, which depends on the normative error concealment scheme, and motion vectors of previously coded frames. The expected loss impact of each macroblock is calculated concurrently by recycling the same corruption model in the reverse direction. Furthermore, if there is feedback about packet loss (e.g. ACK/NACK), the stored corruption models for lost macroblocks are updated by error tracking so that the updated models will affect subsequent AIR/UEP accordingly. Finally, packetization of protected data is considered for video transmission over IP networks.

Date Published: 12 November 2001
PDF: 13 pages
Proc. SPIE 4520, Video Technologies for Multimedia Applications, (12 November 2001); doi: 10.1117/12.448233

Published in SPIE Proceedings Vol. 4520:
Video Technologies for Multimedia Applications
Mahmood R. Azimi-Sadjadi; Sassan Sheedvash, Editor(s)