H265.net

Two Loop Filters in KTA

Jie Dong — Sun, 01 Aug 2010 02:00:09 +0000

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[......]

Adaptive Interpolation Filter for Video Coding

Jie Dong — Wed, 21 Jul 2010 10:10:13 +0000

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[......]

Introduction to Test Model under Consideration (TMuC)

Jie Dong — Sun, 27 Jun 2010 04:37:19 +0000

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&[......]

The First JCT-VC Meeting, Dresden, DE

Jie Dong — Sat, 19 Jun 2010 08:51:43 +0000

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[......]

The 92nd MPEG Meeting in Dresden, Germany

Yu Liu — Fri, 22 Jan 2010 07:57:22 +0000

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/.

The 100th MPEG Meeting Held in Suzhou, China on April 16-20, 2012?

Yu Liu — Wed, 20 Jan 2010 13:37:33 +0000

[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!

Final Call for Proposals on H.NGVC/HVC Issued Jointly by VCEG and MPEG

Yu Liu — Wed, 20 Jan 2010 08:23:09 +0000

[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[......]

The 91st MPEG Meeting in Kyoto, Japan

Yu Liu — Wed, 28 Oct 2009 04:33:30 +0000

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.

Delay the Submission of Responses to CfP on HVC, or not?

Yu Liu — Mon, 26 Oct 2009 08:31:57 +0000

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,[......]

Vote for Your Favorite Name of Next Generation Video Coding Standard

Yu Liu — Sun, 11 Oct 2009 02:31:52 +0000

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.