The Joint Collaborative Team on Video Coding (jct-vc) of itu-t wp3/16 and iso/iec jtc 1/sc 29/wg 11 held its second meeting during 21-28 July, 2010 at the itu-t premises in Geneva, ch

JCTVC-B091 [H. Zhu (Zhu)] Improvement of arithmetic coding based on probability aggregation

This proposal is a proposed improvement version of the JCTVC-A027. The two improvements are as follows:

1. 
   Word based input and output
   
2. 
   Improved logProb table of logprobaddvl[64][2].
   

The proponent was not available to present the contribution.

JCTVC-B098 [M. Karczewicz, P. Chen, W.-J. Chien, X. Wang (Qualcomm)] Variable length coding for coded block flag and large transform

This contribution presents a coding scheme for coded block flag using variable length code. According to the scheme, coded block flags at coding unit level from all Y, U and V components are grouped and coded together. For each component, coded block flags at block level are also grouped and coded together. In both cases, coded block flags from neighboring coding unit or neighboring blocks are used as context in selecting a VLC table. Simulation results show that an average gain of 2.6% can be achieved in coding efficiency.

Large transform (i.e. transform larger than 8x8) coding using variable length code is also presented in the contribution. For large transforms, this contribution proposes that only the first 64 coefficients based on scan order are kept and coded. Simulations show that such a solution provides a coding gain over interleaved transform for both intra and inter predicted blocks.

Proposal to group and code CBF of Y, U and V together, and use neighbored CBF as context.

Report average BR reduction of 2.6% in both cases of CS1 and CS2.

Further proposes to apply the interleaving technique on large transforms differently for first 64 coefficients. Gain reported 2.2% for all-intra, 2.7% for IPPP (no results on hierarchical B).

Gain of CBF and transform claimed to be additive

Establish TE (Nokia, Tandberg participate).

A participant remarked that the current implementation of VLC in TMuC software appears to be not optimum in RDO. Wait with the experiment until this is fixed (mid September according to work plan).