High Efficiency Video Coding

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How Efficient is HEVC?
& n1 U+ F8 z7 o/ n+ bThe new High Efficiency Video Coding (HEVC) / H.265 standard is expected to be more efficient than its predecessor, H.264 Advanced Video Coding. Just how much better it will perform is a crucial question. Will it be enough of an improvement to justify widespread industry adoption of the new standard?

* P2 J5 `* @# z' EBin Li, Gary Sullivan and Jizheng Xu published a performance comparison between H.264/AVC and Working Draft 4 of HEVC in November 2011. You can find the full document and results here:
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Document JCTVC-G399
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Table 4 of the document compares the compression performance of the HEVC test model ("HM") and the H.264 test model ("JM"). On average, HEVC out-performs H.264 by 39% for random access scenarios (e.g. broadcast) and by 44% for low delay scenarios (e.g. video calling).

1 r( T# ?9 q9 Q# ^* R" _3 rThis means that the HEVC codec can achieve the same quality as H.264 with a bitrate saving of around 39-44%.

HEVC is still under development and we might expect to see a further increase in performance from future versions of the draft standard.
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High Efficiency Video Coding
High Efficiency Video Coding (HEVC) is a new Standard under development by the ISO and ITU-T. The Moving Picture Experts Group (MPEG) and Video Coding Experts Group (VCEG) have set up a Joint Collaborative Team on Video Coding (JCT-VC) with the aim of getting the new standard ready for publication in 2012/2013. It's likely to be published jointly as a new MPEG standard and a new ITU-T standard, possibly H.265.
The HEVC Test Model
Following the JCT-VC and MPEG meeting in October 2010, a Test Model for HEVC, HM1, was specified. The Test Model defines two broad categories of video coding tools, for (a) High Efficiency and (b) Low Complexity applications.

! {( Z* ^( m2 V" oWhat's in the Test Model?

& x; b! e. b- D; b. T1 LThe main components are as follows:

Coding unit: Block sizes from 8x8 to 64x64 in tree structure
& L. B0 x& `+ [% c; A, FTransform: Quadtree structured block size from 4x4 to 32x32 samples
0 r# E& }' ^5 p+ l  Y1 P9 eIntra prediction: Up to 34 intra prediction directions
! q2 Z- ]' Q( [: P* GInterpolation: 6- or 12-tap interpolation filter, down to 1/4-sample
8 Q$ L, v. v9 |3 NMotion prediction: Advanced motion vector prediction
Entropy coding: CABAC or Low Complexity Entropy Coding (LCEC)
) i/ _; t6 N& e- oLoop filter: Deblocking filter or Adaptive Loop Filter (ALF)
0 T9 X) H& R' X5 ePrecision: Extended precision options
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Many coding tools have been scheduled for further investigation and may be incorporated into the Test Model if they offer suitable compression gains.

How will it compare to H.264/AVC?

Current indications are that the new standard could provide 2x better video compression performance (i.e. around half the bitrate for a similar quality level) at the expense of significantly higher computational complexity, compared with H.264/AVC.
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7 `) `% n. L& w7 `4 V  B" iWhen will it be finished?

The timescale for completing the HEVC standard is as follows:
February 2012: Committee Draft (complete draft of standard)
July 2012: Draft International Standard
January 2013: Final Draft International Standard (ready to be ratified as a Standard)
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$ x. A* S* k/ w2 m7 O  S, P0 rWhere can I find out more?

JCT-VC Meeting Documents : download JCTVC-C405 for a summary of the HEVC test model HM1.
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  The Joint Collaborative Team
From the ITU website:

"The Joint Collaborative Team on Video Coding is a group of video coding experts from ITU-T Study Group 16 (VCEG) and ISO/IEC JTC 1/SC 29/WG 11 (MPEG) created to develop a new generation video coding standard that will further reduce by 50% the data rate needed for high quality video coding, as compared to the current state-of-the-art AVC standard (ITU-T Rec. H.264 | ISO/IEC 14496-10). This new coding standardization initiative is being referred to as High Efficiency Video Coding (HEVC)."
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7 ~* c( X$ x  q- `To find out more:
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Joint Collaborative Team on Video Coding