Mohammad Kazemi Varnamkhasti

Multiple Description Video Coding Based on Base and Enhancement Layers of SVC and Channel Adaptive Optimization

Supervisor(s) and Committee member(s): Khosro Haj Sadeghi (supervisor), Shervin Shirmohammadi (co-supervisor)


Multiple distortion coding (MDC) is a promising solution for video transmission over lossy channels. In MDC, multiple descriptions of a source are generated which are dependently decodable and mutually refinable. When all descriptions are available, the corresponding quality is called central quality; otherwise it is called side quality. Generally, there exists a trade-off between side and central quality in all MDC schemes. MDC methods which provide better central-side quality trade-off are of more interest to designers.

In this thesis a new MDC scheme is introduced which has better trade-off between side and central quality compared to existing schemes. In other words, for the same central quality, it provides higher side quality; or equivalently for the same side quality, it has higher central quality. This method is based on the mixing of the base and enhancement layers of Coarse-Grain Scalable (CGS) coding and hence is called Mixed Layer MDC (MLMDC). At the central decoder the layers are separated and we have two-layer quality, such as in the CGS decoder. At the side decoder, some descriptions are not available and hence we cannot separate the layers, directly. We propose to use estimation for this purpose. MLMDC for two-description coding and four-description coding is implemented in JM16.0, H.264/AVC reference software. The experimental results show that for videos which have dynamic enough content (texture and motion activity), MLMDC in comparison to the conventional MDCs provides higher side quality for the same central quality. In addition, for video transmission over channels with packet loss (such as the Internet), MLMDC provides higher average video quality, in particular for four-description coding.

In error prone environments, we need to have higher side quality while in less noisy conditions higher central quality is more important. Therefore, in order to have the best quality in different channel conditions, optimization is needed. For this purpose, a new model for end-to-end distortion is introduced which takes into account both quantization and transmission distortions for predicting the quality at the receiver side. The transmission distortion is the result of error propagation which in turn originated from the mismatch between side and central decoder outputs. The derived model is applicable for all DCT-domain MDCs. With experimental results, the model is verified first and then used for MDCs optimization. The results show the performance of the optimizer and also MLMDC higher video quality compared to that of conventional MDCs when they are designed optimally.

While the thesis is in Farsi, its first part is available in English in the following paper:
Kazemi, M.; Sadeghi, K.H.; Shirmohammadi, S., “A Mixed Layer Multiple Description Video Coding Scheme”, IEEE Transactions on Circuits and Systems for Video Technology, Volume: 22 Issue:2, Feb. 2012, pp. 202-215,

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