KTA employs two concatenating loop filters: the deblocking loop filter and the adaptive loop filter.
The deblocking loop filter, inherited from H.264/AVC, alleviates the blocking artifacts caused by the block-based DCT+MCP video coding framework. It uses a bank of low-pass filters, which are adaptively applied to block boundaries according to the boundary strength (BS), and provides better visual quality and improved capability to predict other pictures.
Adaptive loop filter (ALF; click here for introduction) is placed in the MCP loop after the deblocking process, and is used to restore the degraded picture (caused by compression) such that the MSE between the reconstructed and source frames is minimized. The coefficients of ALF are calculated and transmitted on a frame basis and the minimum mean squared error (MMSE) estimator is used. For each degraded frame, ALF can be applied to the entire frame or to local areas. The former is known as frame-based ALF. In the latter case, additiona[......]
Permanent Link: Two Loop Filters in KTA
Why use interpolation in video coding?
Motion-compensated prediction (MCP) is the key to the success of the modern video coding standards, as it removes the temporal redundancy in video signals and reduces the size of bitstreams significantly. With MCP, the pixels to be coded are predicted from the temporally neighboring ones, and only the prediction errors and the motion vectors (MV) are transmitted. However, due to the finite sampling rate, the actual position of the prediction in the neighboring frames may be out of the sampling grid, where the intensity is unknown, so the intensities of the positions in between the integer pixels, called sub-positions, must be interpolated and the resolution of MV is increased accordingly.
Interpolation in H.264/AVC
In H.264/AVC, for the resolution of MV is quarter-pixel, the reference frame is interpolated to be 16 times the size for MCP, 4 times both sides. As shown in Fig. 1(a), the interpolation defined in H.264 includes two stages, inter[......]
Permanent Link: Adaptive Interpolation Filter for Video Coding
TMuC is the initial test model of JCT-VC, but it is not formally adopted as a test model of the draft standard, as no thorough testing has been performed for such a possible combination of tools. The coding tools in TMuC will be further tested to confirm their effectiveness, before adopted in a formal test model.
TMuC provides more flexibility than H.264/AVC. The basic coding unit, called coding tree block (CTB), which has a similar role to the macroblocks in H.264/AVC, can have variable sizes (a power of 2). The sizes of the largest and smallest CTBs are specified in the sequence parameter set (SPS). A frame is divided into non-overlapped largest CTBs (LCTB), e.g., 128×128, and then each LCTB can be further divided in a recursive tree representation.
Each CTB has its own prediction type (intra/inter) and prediction partition. The partition can be symmetric, just as in H.264/AVC, or asymmetric, e.g., 64×64 block can be partitioned into 64×16/64×48 or 16×64/48&[......]
Permanent Link: Introduction to Test Model under Consideration (TMuC)
During Apr. 15-23, 2010, the first meeting of JCT-VC was held in Dresden, DE. In the meeting, 27 responses to the Call for Proposal, issued in Jan. 2010, were reviewed and the associated video material was evaluated in extensive subjective tests.
Tentative Conclusions from CfP Responses Reviews
Coding tools used in respective proposals are listed in JCTVC-A203. High-level noteworthy aspects from the review of the proposals and the outcome of the subjective tests are outlined:
- Substantial progress in coding efficiency has clearly been demonstrated, compared with H.264/AVC
- There is no indication of a need to change the fundamental architecture of “conventional” hybrid video coding designs to achieve a substantial improvement
- Inclusion of support of larger block sizes in a highly variable (typically tree-structured) block segmentation approach is a major common theme, although large block sizes were not found in all proposals that did well subjectively (and objectively)
- Modif[......]
Permanent Link: The First JCT-VC Meeting, Dresden, DE
The 92nd MPEG meeting is hosted by the Institut für Informationsverarbeitung of Leibniz Universität Hannover.
- The first JCT meeting will be held on 15-23 April, 2010
- AhGs will meet on 18 April, 2010
- The 92nd MPEG meeting will be held on 19-23 April, 2010
All meetings will take place in the art’otel dresden. The official web site is accessible now at http://mpeg.tnt.uni-hannover.de/.
Permanent Link: The 92nd MPEG Meeting in Dresden, Germany
The 100th MPEG Meeting Held in Suzhou, China on April 16-20, 2012?
2010-01-20 News Post Comment Views(1,439)[Update]: Confirmed by MPEG official website, the 100th MPEG meeting will be indeed held in Suzhou, China on April 16-20, 2012!
The China National Body (CNNB) first proposed to hold the 100th MPEG meeting in Suzhou, China on April 16-20, 2012 during this Kyoto MPEG meeting. This proposal has a good chance of being approved by MPEG plenary if there are no other competitors. Good luck to CNNB!
The plan of next eight MPEG meetings (from 92nd to 100th) is listed as follows:
| 100th | Suzhou | China | 2012/04/16-20 |
| 99th | ? | ? | 2012/01/??-?? |
| 98th | ? | U.S.A | 2012/10/17-21 |
| 97th | Torino | Italy | 2011/07/17-21 |
| 96th | Geneva | Switzerland | 2011/03/21-25 |
| 95th | ? | Korea | 2011/01/24-28 |
| 94th | Guangzhou | China | 2010/10/18-22 |
| 93rd | Geneva | Switzerland | 2010/07/26-30 |
| 92nd | Dresden | Germany | 2010/04/19-23 |
Keep updating on the plan of MPEG meetings!
Permanent Link: The 100th MPEG Meeting Held in Suzhou, China on April 16-20, 2012?
Final Call for Proposals on H.NGVC/HVC Issued Jointly by VCEG and MPEG
2010-01-20 News 3 Comments Views(2,525)[Update]: A new email reflector, jct-vc@lists.rwth-aachen.de, is created for discussions of the new team effort. For subscription, you should follow this link: http://mailman.rwth-aachen.de/mailman/listinfo/jct-vc. Only subscribers to the list will be able to send messages to this list.
During the 39th VCEG and 91st MPEG meeting held in Kyoto, Japan on January 17-22, 2010, the call for proposals (CfP) on video compression technology (H.NGVC/HVC) will be finally issued jointly by ITU-T SG16 Q.6 (VCEG) and ISO/IEC JTC1/SC29/WG11 (MPEG) on January 22, 2010. A Joint Collaborative Team (JCT) on Video Coding Standard Development will also be established accordingly between VCEG and MPEG.
Some minor modifications to draft CfP issued in November 2009 are made. The modifications involve the timeline, test conditions and test fees, etc., as follows:
- Timeline
The timeline of the Call for Proposals is changed:
2010/01/22: Final Call for Proposals.
2010/01/22: For[......]
Permanent Link: Final Call for Proposals on H.NGVC/HVC Issued Jointly by VCEG and MPEG
The 91st MPEG Meeting, hosted by Information Processing Society of Japan/ Information Technology Standards Commission of Japan (IPSJ/ITSCJ) , will be held at Kyoto Research Park on 18-22 January 2010, in Kyoto, Japan.
The official web site is accessible now at http://mpeg.espalier.co.jp/, and the registration information is listed as follows:
Delegates are requested to contribute a Facilities fee of JPY 40,000 (about US$400) before or on 2009-12-05.
Delegates who register after 2009-12-05 will be charged JPY 50,000.
Mandatory document handling fee (for the WG 11 meeting website management): JPY 2,000.
Permanent Link: The 91st MPEG Meeting in Kyoto, Japan