Sapporo JCT-VC and MPEG Meetings - Jun/Jul 2014
NGCodec was at the JCT-VC/MPEG Meeting in Sapporo to help the industry to continue with the development of the HEVC standard. This was a busy meeting where we did substantial work over 9 days. JCT-VC finished the work on the 2nd version of the HEVC text covering the enhancements related to scalability (SHVC), completed the work on HEVC Test Model (HM15) software and text, the version 1 conformance and accelerated the work in relation to the coding of screen content (SCC). They were a number of additional MPEG activities that were conducted outside JCT-VC, mostly in relation to High Dynamic Range video (HDR) and royalty free codecs.
HEVC/H.265 Version 2 (SHVC)
The 2nd version of the specification was finalised at this meeting. This is a new version of the HEVC specification including some small errata, some new SEI messages and some scalable profiles based on HEVC (SHVC). We made some small changes on some of the techniques that were present at the previous working draft and finished the profile definition. The work was mostly in relation the the colour gamut scalability (CGS), up-sampling and phase offset (needed for interlace to progressive scalability) and high level syntax work. It was adopted at the output of the meeting to create two profiles, Scalable Main Profile and Scalable Main 10 Profile. This will be suitable for applications that required scalability (resolution, frame rate, quality, color gamut, bit dept, hybrid, interlace to progressive, etc) and offers substantial gains in compression efficiency compared with Simulcast. Final work was also performed on a Hybrid approach, where the base layer could be AVC/H.264 and the enhancement will be based on HEVC.
Screen Content Coding (SCC) Version 3
JCT-VC evaluated a number of techniques for Screen Content Coding (SCC) under consideration, those include: Intra Block Copy, Adaptive Colour Transform, Palette Mode Coding, Intra Line Copy, Intra String Copy, Vector Entropy Coding and Inter-component Prediction . The results were considered very encouraging and offering substantial compression efficiency gains for this type of content compared with current 4:4:4 profiles standardised in HEVC RExt (version 2). JCT-VC created the first version of the working draft (WD) for the SCC that included Intra Block copy, Adaptive Colour Transform and Palette Mode coding, the goal of this work is delivering a new standard for efficient encoding of Screen and Mixed Content video that are envisioned to reach FDAM (Final Draft) stage in February 2016 (previously Oct 2015).
New 4:4:4 16 Intra Profile
An additional 4:4:4 16 Intra Profile was defined at this meeting (High Throughput 4:4:4 16 Intra), that allows higher bit rates being supported, specially for very high quality applications like high end professional content creation cameras and archiving allowing nearly lossless operation at a guarantee 2:1 compression ratio and the coding of visually lossless video at around 8-16:1 compression ratio. Allowing to use HEVC in high quality production environments.
HDR and WCG
Further work was conducted in relation to the support of HDR and the XYZ colour space in HEVC. There were very active work on defining the requirements and the way to technically address them. This is an area of great interest to several markets (i.e. broadcasting), it was decided at this meeting to prepare a Call for Evidence on this area to have a better understanding of the technology available at the moment. Based on the current conversations it seems to be two options to deliver HDR, the first option is to use Main 10 (or Main 12) with some transfer function adapted for HDR displays and the second options is to deliver a scalable approach that can support the legacy displays and the new HDR displays.
Royalty free video
MPEG continued the work on a royalty free video standards. MPEG decided to move to Final Draft of International Standard on WebVC the format based on based on AVC/H.264 CBP at the previous meeting. It continued working on the Video Coding for Browsers, based on the previous work done by Google on VP8, it was decided to achieve Committee Draft at this meeting with the goal of producing Draft text for DIS at the end of this meeting.
There were a number of 3D/multiview related activities, including AVC+depth, MVC+depth, Multiview HEVC, those were worked on by JCT-3V.