In the beginning plenary of 90th MPEG meeting on Oct. 26, several national bodies, such as USNB, FRNB, SGNB, and CNNB, recommended to delay the submission date of responses to the Call for Proposal (CfP) on HVC from December 2009 to March 2010. The major concerns from the national bodies are:
- the need of sufficient time to finalize the establishment of collaborative team with VCEG and only then issue a joint CfP;
- the need of sufficient time to determine the cost of the subjective evaluation tests after the CfP is finalized;
- the need of sufficient time to refine the CfP test conditions/materials and only then generate the proposed bitstreams;
- the need of sufficient time to define the complexity evaluation criterion in an objective method for quantitative analysis,
- the need of sufficient time to perform the subjective evaluation tests but currently planned in the year-end holidays period.
This recommendation aroused controversy between the delegates of national bodies and the convenor,[......]
Permanent Link: Delay the Submission of Responses to CfP on HVC, or not?
Vote for Your Favorite Name of Next Generation Video Coding Standard
2009-10-11 News 14 Comments Views(2,909)As mentioned in the previous post, MPEG/VCEG has launched a new video coding standardization project, which is tentatively named as High-performance Video Coding (HVC). The formal name is still under discussion. A short list of candidates most supported in MPEG-newvid mailing list are summarized by Ken McCann from ZetaCast,
- HVC – High-efficiency Video Coding (Note: not High-performance Video Coding? I prefer the latter)
- EPVC – Enhanced Performance Video Coding
- HEVC – High Efficiency Video Coding
- HCEV – High Coding Efficiency Video
An online poll was set up at Doodle [Poll: Name of new MPEG/VCEG Standard]. Your opinion is very important. Please vote with your real name to keep the process transparent.
Permanent Link: Vote for Your Favorite Name of Next Generation Video Coding Standard
The intra prediction in H.264/AVC is a type of spatial domain directional prediction, which means different intra prediction modes represent different prediction directions, such as horizontal, vertical, and diagonal. An intra-coded MB can be partitioned into 4×4, 8×8, or 16×16 intra prediction blocks. The 4×4 and 8×8 intra prediction blocks have nine prediction directions, respectively, and the 16×16 block has four. Hence, totally 22 (9+9+4) intra prediction modes are used in H.264/AVC. The residue usually has high energy along the direction of prediction, as edges are more difficult to be predicted than smooth areas.
Mode-dependent directional transform (MDDT) was proposed to compact the residue produced by intra prediction. It consists of a series of pre-defined separable transforms; each transform is efficient in compacting energy along one of the prediction directions, thus favoring one of the intra modes. The type of MDDT is coupled with the selected[......]
Permanent Link: Mode-Dependent Directional Transform (MDDT) in JM/KTA
3. Adaptive Loop Filter
As far as adaptive loop filter (ALF) is concerned, there are three types of ALF: frame-based, block-based and quadtree-based ALFs. All of them are based on wiener filter, but with different filtering control basis. In frame-based ALF [VCEG-C437/AI14, C402], only one picture level flag is used to signal the decision of filtering or non-filtering.
Although wiener filter can restore the reconstructed picture to the original picture globally, there are degraded pixels locally. Since the degraded area reduce the filtering efficiency, if these areas are not filtered, the capabilities of picture restoration and loop filtering are improved. Therefore, block-based ALF [VCEG-AI18/AJ13] use explicit flags for filtering on-off on block by block basis, while quadtree-based ALF [VCEG-C181/AK22] introduces a quadtree data structure to carry out the variable-size block filtering.
3.1 Block-based Adaptive Loop Filter
Block-based ALF is an improvement of frame-based ALF. Figure 2[......]
Permanent Link: Adaptive Post/Loop Filters in JM/KTA – Part 2
1. Introduction
The basic idea of adaptive post/loop filter is the same. Both of them use adaptive wiener filtering technique to improve the quality of reconstructed picture which is degraded by compression. The difference between them is whether the filtering process is applied in or out of the core coding loop, as shown in Figure 1, to improve the quality of reconstructed picture or just displayed picture.
Figure 1. Block diagram of JM/KTA
2. Adaptive Post Filter
In H.264/AVC, there is already an existing post-filter hint SEI message [JVT-S030/T039/U035] which provides the coefficients of a post-filter or correlation information for the design of a post-filter for potential use in post-processing of the output decoded pictures to obtain improved displayed quality.
To find the coefficients of adaptive wiener filter, the following cost function based on the whole frame is minimized:
(1)
where R is the reconstructed picture, R’ is the filtered picture, and I is the original pic[......]
Permanent Link: Adaptive Post/Loop Filters in JM/KTA – Part 1
The 90th MPEG/50th JPEG Meeting, hosted by Xidian University, will be held at Sheraton Hotel on 26-30 October 2009, in Xian, China.
The official web site is accessible now at http://see.xidian.edu.cn/conference/mpegjpeg/, and the early bird registration date is 30 September 2009.
Permanent Link: The 90th MPEG Meeting in Xi’an, China
As well-known, JVT (a joint video team between MPEG and VCEG) has achieved great success in the standardization of the state-of-the-art video compression, including H.264/AVC, SVC, and MVC. The academic and industry want to continue the success in the collaboration between MPEG and VCEG. Some proposals from VCEG suggest the H.NGVC (or H.265) standardization should be collaboratively done with MPEG to produce a significantly advanced video coding standard and to avoid producing multiple similar standards, which confuse the market. VCEG agrees that conducting this work jointly with MPEG will be beneficial to avoid duplication of efforts in this area. Therefore, in this MPEG London meeting, a joint meeting between MPEG and VCEG discusses the future collaboration. However, the collaboration method arouses a lot of controversy, focusing on which one of the following practical experiences should be chosen:
- Practical experience 1: MPEG-2, a integrate part of video subgroup when under WG 11 a[......]
Permanent Link: Future Collaboration between MPEG and VCEG
Current Status of HVC (High-Performance Video Coding) in MPEG
2009-07-03 News 11 Comments Views(7,642)In the last MPEG meeting, MPEG issued a Call for Evidence (CfE) on High-performance Video Coding (HVC). Nine responses to the CfE are received in this meeting (89th MPEG London). Those reponse proposals adopt typical coding tools in KTA, such as adaptive loop filter (ALF), extended macroblock size (EMS), larger transform size (LTS), internal bit depth increasing (IBDI), adaptive quantization matrix selection (AQMS), as well as new tools, such as modified intra prediction, modified de-block filter, decoder-side motion vector derviation (DMVD).
The objective experimental results show that 20% average bit reduction is achieved compared with H.264/AVC High Profile for all classes of test video sequences (Class A: 19%, Class B:25%, Class C:22%, Class D: 15% bit reductions, respectively). Subjective evalution is also conducted during this meeting. The purpose of subjective evaluation is identifying examples that give the best evidence and assessing whether the evidence is large enough. The s[......]
Permanent Link: Current Status of HVC (High-Performance Video Coding) in MPEG