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-B095 [I. S. Chong, W.-J. Chien, N. Malayath, M. Karczewicz (Qualcomm)] Encoder complexity analysis and performance report on adaptive loop filter

In this contribution, encoder complexity aspects of various proposed Adaptive In-Loop Filter (ALF) algorithms are evaluated along with their coding efficiencies. A performance report according to the ALF method categories mentioned in the AHG report on in-loop filtering JCTVC-B007 was presented, i.e., i) separate QT vs. CU synchronized and ii) filter shapes and types.

It was suggested to establish the following guidelines for the work:

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  Avoid extreme amounts of multi-pass processing for encoding experiments (e.g., 18 pass non-separable and 34-pass separable filter designs), and
  
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  Consider post-filtering in the evaluation of filtering methods.
  

The group agreed with these suggestions.

It was noted that one filtering pass can potentially be avoided in the encoder if the filter is a post filter.

It was reported that there may not be a benefit to using a separate quadtree for the filter, relative to that used for the coding units.

Subjective quality evaluation results were not reported – which are clearly desired.