A low complexity encoding scheme for coarse grain scalable video coding

Sun

Zhu

et al. 2020

IEEE Trans. Multimedia

Section: B Expected Values Based Non-square Mode Prediction (Evb-nsmp)mentioning

confidence: 99%

Fast Depth and Inter Mode Prediction for Quality Scalable High Efficiency Video Coding

Sun

Zhu

et al. 2020

IEEE Trans. Multimedia

“…As mentioned above, the residual coefficients obey a Gaussian distribution. Suppose that the residual coefficients of two parts in each division can be respectively modeled as [40]…”

Section: Significant Difference Based Depth Early Termination (Sdbmentioning

confidence: 99%

Efficient Multi-Strategy Intra Prediction for Quality Scalable High Efficiency Video Coding

IEEE Trans. on Image Process.

Zhu

Sun

et al. 2019

As an extension of High Efficiency Video Coding (HEVC), the Scalable High Efficiency Video Coding (SHVC) introduces multiple layers with inter-layer predictions, which greatly increases the complexity on top of the already complicated HEVC encoder. In Intra prediction for Quality SHVC, Coding Tree Unit (CTU) allows recursive splitting into four depth levels, which considers 35 Intra prediction modes and interlayer reference (ILR) mode to determine the best possible mode at each depth level. This achieves the highest coding efficiency but incurs a substantially high computational complexity. In this paper, we propose a novel Intra prediction scheme to effectively speed up the enhancement layer Intra-coding in Quality SHVC. The new features of the proposed framework include: First, spatial correlation and its correlation degree are combined to predict most probable depth level candidates. Second, for a given depth candidate, based on the probabilities of the ILR mode, we check the ILR mode by examining the residual distribution based on skewness and kurtosis to determine whether the residuals follow a Gaussian distribution. In that case, the Intra prediction comparisons, which require a high complexity, are skipped. Third, during Intra prediction selection from 35 Intra prediction modes, spatial and inter-layer correlations are combined with the local monotonicity of the Hadamard costs associated with the modes in a small neighborhood, to examine only a portion of Intra prediction modes. Finally, a hypothesis testing on the currently selected depth level is performed to examine whether the residuals present significant differences within their block to early terminate depth selection. The proposed multi-step multistrategy scheme aims to minimize the number of depth selections while greatly reducing the mode decision complexity for a depth candidate in a hierarchical fashion. Our experimental results demonstrate that the proposed scheme can achieve a speedup gain of more than 75% in average on the test video sequences, while maintaining almost the same coding efficiency. .

“…For benchmark comparison, the original JSVM 9.19 with R-D optimization is also evaluated. The block size is constrained to be no less than intra enabled ← f alse 5: else // colocated BL blk = INTRA 6: inter enabled ← f alse 7 8x8 for INTER modes, and forced inter-layer motion prediction are enabled, for both default JSVM and with proposed algorithm implemented. The hierarchical B structure with GOP (group of picture) length of 16 is used with intra-picture period of 64.…”

Section: Performance Evaluationmentioning

confidence: 99%

“…There are many research works focusing on SVC encoding complexity reduction (with slight coding efficiency sacrifice) [7,8], where macroblock mode correlation for intercoded blocks between adjacent layers is modeled to directly determine the mode at EL without going through the expensive rate-distortion optimization. Low complexity mode decision for intra-coded blocks has also been studied in [9].…”

Section: Introductionmentioning

confidence: 99%

One-pass mode decision for low-complexity and high-efficiency encoding of quality scalable video

2013 IEEE International Conference on Multimedia and Expo Workshops (ICMEW)

2013

This paper presents a novel one-pass mode decision algorithm for encoding multiple quality layers, following the coarse grain scalability coding structure in the H.264/SVC standard. In our solution, motion estimation (ME) is carried out only once at the base layer using the reconstructed picture from the highest enhancement layer. The same motion vectors are used for all layers to not only avoid multiple ME processes at different layers, but also save the overhead bits. In addition, early SKIP/DIRECT mode decision is introduced to further boost the encoding speed. The encoder produces fully compliant SVC bit streams. Although the method is applicable to both coarse grain scalability (CGS) and medium grain scalability (MGS), we have examined its performance over CGS only. We demonstrate that more than 2x speedup for three-layer coding against the conventional H.264/SVC encoding using the reference software over 7 test sequences. Significantly, this complexity saving is achieved simultaneously with increase in the coding efficiency! Although the base layer requires slightly higher bit rate (2.5% in terms of the BD-Rate), the enhancement layers enjoy lower rates (5.7% and 2.2% reduction for the total of two and three layers, respectively), on average of 7 test sequences.