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 tenth meeting during 11-20 July 2012 at the City Conference Centre (ccc), a k. a

JCTVC-J0258 Interlaced coding performance and chroma consideration [Jérôme Viéron, Pierre Larbier, Jean-Marc Thiesse (Ateme)]

This contribution reports on an assessment of both objective and subjective performance on interlaced material coding with HM 7.0. Objective performance is reported against H.264/AVC, and visual degradations on chroma components are highlighted when encoding at low bitrates.

This degradation reportedly results from the misalignment of chroma samples locations of top field with regard to bottom field. An update of previous proposal JCTVC-I0502 is consequently evaluated while considering an SEI modification. Objective improvements associated with chroma artifact correction are reported.

For AVC, both PicAFF and MBAFF were checked.

The previously proposed SEI message for pre- and post-processing of the chroma positions was also discussed in the contribution. It was asserted that this was beneficial in PSNR terms even when the decoding post-processing was not performed. A participant commented that multiple cascaded stages of this (without the post-compensation) might result in substantial degradation.

It was commented that the current signalling in VUI may actually be able indicate what the SEI message is indicating.

The HEVC was not optimized to adjust the picture coding order for optimized field coding performance. It was commented that this would be important to do for a more proper assessement of the situation, as any real encoder design would compensate for this.

No action was taken on the SEI proposal part.