For rate-distortion optimized rate allocation in JVT Scalable Video Coding (SVC), the distortion impact of every FGS NAL unit on the global reconstruction quality is calculated by repeatedly bitstream decoding, which leads to high complexity. In this paper, a fast rate allocation algorithm by modeling distortion estimation is proposed. Based on the hypothesis that DCT residual coefficients follow Laplacian distribution, we establish the distortion estimation model by calculating quantization error of each FGS NAL unit and analyzing the prediction in hierarchical B coding structure. Besides, the parameter in the model is updated according to the distribution of residual coefficients decoded at the base layer within every frame. Experimental results show that compared to the existing method of R-D optimized rate allocation in SVC, the proposed method results in a reduction in decoding time of nearly 50%, and save the runtime of rate allocation by 45.3%, while the PSNR loss of decoded sequence is only 0.04 dB on average.
The coding efficiency of Wyner-Ziv frames relies considerably on the quality of side information and the capability to
model the statistical dependency between the original frame and side information. In the field of distributed multi-view
video coding (DMVC), there are two kinds of side information, namely temporal side information (TSI), which is
generated by exploiting the temporal correlation, and inter-view side information (IVSI), which is generated by
exploiting the inter-view correlation. This paper proposes a new fusion method to get better side information by the
region-based combination of TSI and IVSI. Besides, an improved statistical model of "correlation channel" is proposed
to estimate the statistical dependency between the original frame and side information at the decoder. We call it Region-based
Correlation Channel Model (RCCM). The RCCM models the "correlation channel" between original frame and
side information at a fine granularity level by detecting the spatial quality variation of side information within each
Wyner-Ziv frame. Experimental results demonstrate that the RCCM can more accurately model the "correlation channel" between the original frame and side information and thus, less bits are required for decoding a Wyner-Ziv frame.
Bit rate adaptation is one of the basic problems in universal multimedia access. Therefore, in many cases, there exists a
strong requirement for a very fast transcoding implementation. Usually, open-loop transcoding architecture is the desired
solution with the lowest computational complexity. However, severe drift error makes it infeasible to most applications.
In this paper, we propose a drift-compensated coding optimization scheme, by which generated bitstreams can be
effectively transcoded into lower bitrate by open-loop transcoder with little drift propagation. The encoder integrates a
virtual open-loop transcoder, in which drift error is effectively compensated by suitably adjusting the RD based mode
selection and motion estimation for each macroblock. Simulation results show that compared with traditional coding, the
proposed mode selection scheme can yield better coding efficiency when rate reduction transcoding to low bitrate
occurs. And meanwhile, it does not degrade the coding efficiency in comparison with the normal single layer coding in
For low-delay applications in Scalable Video Coding, there are two alternative coding strategies based on AR-FGS for
compressing multiple FGS layers. However, their coding efficiencies both suffer largely from the inherent drifting errors.
In this paper, a more efficient multiple FGS layers coding structure is presented, which can provide higher coding
performance within wide bitrate range and stronger error resilience. This is achieved by incorporating the partial-reconstructed
enhancement layer references, instead of the complete-reconstructed ones, into the motion-compensated
prediction loop of the FGS layers. Thereupon the prediction drift can be effectively decreased, especially for the middle
bitrate points. Further, through selecting different-quality enhancement layer references generated with cycle-based
reconstruction mechanism, more flexible video quality can be supported to be more suitable for varied practical
This paper presents a new Base Layer coding scheme which introduces the rate-distortion optimization mode decision into hierarchical-fashion B-picture coding with open-loop structure. It can not only achieve high coding performance for Base Layer bit-rate point and meanwhile, but the scheme also keep the strong correlation between Base Layer and Enhancement Layer implemented by 3D subband scalable video codec, because they share the similar lifting based Motion-Compensated Temporal Filtering (MCTF) decomposition structure. In addition, how to exploit the correlation between Base Layer and Enhancement Layer is also investigated. Experimental results show this method improves the coding performance and visual quality at both low and high bit-rate points.