H.NGVC / H.265

H.265 or H.NGVC (Next-generation Video Coding) is a hypothetical future ITU-T recommendation for video compression coding under study for potential development by the ITU-T Video Coding Experts Group (VCEG). The study of potential technology advances which will enable creation of H.265 is a major part of the current work of VCEG. H.265 is a long-term video coding standard, launched by VCEG. As indicated in ITU-T SG16’s homepage, VCEG plans to complete the requirement definition and begin the detailed algorithm design for H.265 in the study period 2005-2009, and if the progress in contribution technology is sufficient, H.265 is expected to be finalized in 20010-2012.

Currently, H.265 hasn’t been formalized and VCEG keeps seeking proposals and information regarding the possibility of a major gain in performance to justify the step from H.264 to H.265. Though the necessary scope of H.265 is yet to be determined, it is agreed that among the goals will be [AA01]:

• simplicity and “back to basics” approach
• high coding efficiency, e.g., two times compared with H.264
• computational efficiency, considering both encoder and decoder
• loss/error robustness
• network friendliness
• other considerations as necessary

Backward/forward compatibility is not assumed to be required for H.265, as H.265 is a brand new standard instead of an extension of H.264. Although some agreements about the goals of an H.265 project have been reached, e.g. computational efficiency and high compression performance, the current state of technology does not yet seem mature for creation of an entirely new H.265 standard, and all contributions are modifications to KTA JM11, a reference H.264 encoder by the MPEG/VCEG Joint Video Team. In April 2009, the scope of the project was changed to H.NGVC, with a H.264+ standard being the most likely outcome.
The preliminary requirements for NGVC are bit rate reduction of 50% at the same subjective image quality and computational complexity comparing to H.264 High profile, with computational complexity ranging from 1/2 to 3 times as that of H.264. NGVC should be able to provide 25% bit rate reduction along with 50% reduction in complexity at the same perceived video quality as H.264 High profile.

Features:

1. 2-D non-separable adaptive interpolation filter (AIF)
2. Separable AIF
3. Directional AIF
4. "Supermacroblock" structure up to 64x64 with additional transforms
5. Adaptive prediction error coding (APEC) in spatial and frequency domain
6. Adaptive quantization matrix selection (AQMS)
7. Competition-based scheme for motion vector selection and coding
8. Mode-dependent KLT for intra coding

References:

1. http://www.h.265.net/
2. http://tvbeurope.com/index2.php?option=com_content&do_pdf=1&id=358