High Efficiency Video Coding (HEVC) provides superior coding efficiency than previous video coding standards at the cost of increasing encoding complexity. The complexity increase of motion estimation (ME) procedure is rather significant, especially when considering the complicated partitioning structure of HEVC. To fully exploit the coding efficiency brought by HEVC requires a huge amount of computations. In this paper, we analyze the ME structure in HEVC and propose a parallel framework to decouple ME for different partitions on many-core processors. Based on local parallel method (LPM), we first use the directed acyclic graph (DAG)-based order to parallelize coding tree units (CTUs) and adopt improved LPM (ILPM) within each CTU (DAGILPM), which exploits the CTU-level and prediction unit (PU)-level parallelism. Then, we find that there exist completely independent PUs (CIPUs) and partially independent PUs (PIPUs). When the degree of parallelism (DP) is smaller than the maximum DP of DAGILPM, we process the CIPUs and PIPUs, which further increases the DP. The data dependencies and coding efficiency stay the same as LPM. Experiments show that on a 64-core system, compared with serial execution, our proposed scheme achieves more than 30 and 40 times speedup for 1920 × 1080 and 2560 × 1600 video sequences, respectively.

Efficient Parallel Framework for HEVC Motion Estimation on Many-Core Processors

High Efficiency Video Coding (HEVC) uses a very flexible tree structure to organize coding units, which leads to a superior coding efficiency compared with previous video coding standards. However, such a flexible coding unit tree structure also places a great challenge for encoders. In order to fully exploit the coding efficiency brought by this structure, huge amount of computational complexity is needed for an encoder to decide the optimal coding unit tree for each image block. One way to achieve this is to use parallel computing enabled by many-core processors. In this paper, we analyze the challenge to use many-core processors to make coding unit tree decision. Through in-depth understanding of the dependency among different coding units, we propose a parallel framework to decide coding unit trees. Experimental results show that, on the Tile64 platform, our proposed method achieves averagely more than 11 and 16 times speedup for 1920x1080 and 2560x1600 video sequences, respectively, without any coding efficiency degradation.

A Highly Parallel Framework for HEVC Coding Unit Partitioning Tree Decision on Many-core Processors

The Range Extensions (RExt) of the High Efficiency Video Coding (HEVC) standard have recently been approved by both ITU-T and ISO/IEC. This set of extensions targets video coding applications in areas including content acquisition, postproduction, contribution, distribution, archiving, medical imaging, still imaging, and screen content. In addition to the functionality of HEVC Version 1, RExt provide support for monochrome, 4:2:2, and 4:4:4 chroma sampling formats as well as increased sample bit depths beyond 10 bits per sample. This extended functionality includes new coding tools with a view to provide additional coding efficiency, greater flexibility, and throughput at high bit depths/rates. Improved lossless, near-lossless, and very high bit-rate coding is also a part of the RExt scope. This paper presents the technical aspects of HEVC RExt, including a discussion of RExt profiles, tools, applications, and provides experimental results for a performance comparison with previous relevant coding technology. When compared with the High 4:4:4 Predictive Profile of H.264/Advanced Video Coding (AVC), the corresponding HEVC 4:4:4 RExt profile provides up to $\sim 25$ %, $\sim 32$ %, and $\sim 36$ % average bit-rate reduction at the same PSNR quality level for intra, random access, and low delay configurations, respectively.

Overview of the Range Extensions for the HEVC Standard: Tools, Profiles, and Performance

A moving picture coding apparatus includes an intra-inter prediction unit which calculates a second motion vector by performing a scaling process on a first motion vector of a temporally neighboring corresponding block, when selectively adding, to a list, a motion vector of each of one or more corresponding blocks each of which is either a block included in a current picture to be coded and spatially neighboring a current block to be coded or a block included in a picture other than the current picture and temporally neighboring the current block, determines whether the second motion vector has a magnitude that is within a predetermined magnitude or not within the predetermined magnitude, and adds the second motion vector to the list when the intra-inter prediction unit determines that the second motion vector has a magnitude that is within the predetermined magnitude range.

Moving picture coding method, moving picture coding apparatus, moving picture decoding method, moving picture decoding apparatus, and moving picture coding and decoding apparatus

A video coding or decoding method operable to generate blocks of quantised spatial frequency data by quantising the video data according to a selected quantisation step size and a matrix of data modifying the quantisation step size for use at different respective block positions within an ordered block of samples, the method being operable with respect to at least two different chrominance subsampling formats; comprises for at least one of the chrominance subsampling formats, defining one or more quantisation matrices as one or more predetermined modifications with respect to one or more reference quantisation matrices defined for a reference one of the chrominance subsampling formats.

Data encoding and decoding

The lossless coding mode of the High Efficiency Video Coding (HEVC) main profile that bypasses transform, quantization, and in-loop filters is described. Compared to the HEVC nonlossless coding mode with the smallest quantization parameter value (i.e., 0 for 8-b video and -12 for 10-b video), the HEVC lossless coding mode provides perfect fidelity and an average bit-rate reduction of 3.2%-13.2%. It also significantly outperforms the existing lossless compression solutions, such as JPEG2000 and JPEG-LS for images as well as 7-Zip and WinRAR for data archiving. To further improve the coding efficiency of the HEVC lossless mode, a sample-based angular intra prediction (SAP) method is presented. The SAP employs the same prediction mode signaling method and the sample interpolation method as the HEVC block-based angular prediction, but uses adjacent neighbors for better intra prediction accuracy and performs prediction sample by sample. The experimental results reveal that the SAP provides an additional bit-rate reduction of 1.8%-11.8% on top of the HEVC lossless coding mode.

HEVC Lossless Coding and Improvements

A video codec comprising a processor configured to compute a reconstructed pixel based on a residual pixel and a first prediction pixel and compute a second prediction pixel in a directional intra prediction mode based on the reconstructed pixel, wherein the first and second prediction pixels are located in a same block of a video frame. A method for intra prediction comprising computing a prediction pixel adaptively based on a plurality of reconstructed neighboring pixels, wherein a distance between the prediction pixel and each of the plurality of reconstructed neighboring pixels is one.

Differential pulse code modulation intra prediction for high efficiency video coding

A video codec comprising a processor configured to compute a difference between an original pixel and a prediction pixel to generate a prediction residual, and binarize an absolute value of the prediction residual. A method for video coding comprising computing a difference between an original pixel and a prediction pixel to generate a prediction residual, and binarizing an absolute value of the prediction residual. A video encoder comprising a processor configured to set a number of syntax elements to indicate lossless encoding of some or all coding units (CU) in a video frame, a transmitter configured to transmit a bit stream comprising the syntax elements. A method for video encoding comprising setting a number of syntax elements to indicate lossless encoding of some or all coding units (CU) in a video frame, and transmitting a bit stream comprising the syntax elements.

Binarization of Prediction Residuals for Lossless Video Coding

A method comprising computing predicted values for a plurality of border pixels in a prediction unit (PU) using corresponding left, upper, and upper left adjacent neighboring pixels in the PU, and computing predicted values for a second plurality of pixels in the PU using sample based angular prediction (SAP), wherein the second plurality of pixels comprises all other pixels in the PU besides the plurality of border pixels.

Intra prediction in lossless coding in HEVC

In this paper, we first review the lossless coding mode in the version 1 of the HEVC standard that has recently finalized.
We then provide a performance comparison between the lossless coding mode in the HEVC and MPEG-AVC/H.264
standards and show that the HEVC lossless coding has limited coding efficiency. To improve the performance of the
lossless coding mode, several new coding tools that were contributed to JCT-VC but not adopted in version 1 of HEVC
standard are introduced. In particular, we discuss sample based intra prediction and coding of residual coefficients in
more detail. At the end, we briefly address a new class of coding tools, i.e., a dictionary-based coder, that is efficient in
encoding screen content including graphics and text.

Minqiang Jiang

Papers

HEVC Lossless Coding and Improvements

Differential pulse code modulation intra prediction for high efficiency video coding

Binarization of Prediction Residuals for Lossless Video Coding

Intra prediction in lossless coding in HEVC

On lossless coding for HEVC