High Efficiency Video Coding

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How Efficient is HEVC?
. B) S( X4 o* B* O- g& DThe 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?

Bin 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:

Document JCTVC-G399

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).

This means that the HEVC codec can achieve the same quality as H.264 with a bitrate saving of around 39-44%.
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4 j9 j4 J2 a/ G/ Z& aHEVC 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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& Z: c9 D" p& l* jHigh 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.
4 S, R9 S1 V0 G5 W, N/ fThe HEVC Test Model
9 `. x/ c; q+ R3 c3 [. MFollowing 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.

# D2 @, a. Q7 ?0 C' C1 Q; PWhat's in the Test Model?
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The main components are as follows:

Coding unit: Block sizes from 8x8 to 64x64 in tree structure
Transform: Quadtree structured block size from 4x4 to 32x32 samples
Intra prediction: Up to 34 intra prediction directions
Interpolation: 6- or 12-tap interpolation filter, down to 1/4-sample
" q, }) g4 Z2 y7 t# sMotion prediction: Advanced motion vector prediction
Entropy coding: CABAC or Low Complexity Entropy Coding (LCEC)
Loop filter: Deblocking filter or Adaptive Loop Filter (ALF)
Precision: Extended precision options

* K1 n' g" g) o2 e# `7 a+ B: ~; bMany coding tools have been scheduled for further investigation and may be incorporated into the Test Model if they offer suitable compression gains.

4 S  [8 z* a  B' E! p; wHow 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.

When will it be finished?

The timescale for completing the HEVC standard is as follows:
- V( T6 _2 W& U4 f7 UFebruary 2012: Committee Draft (complete draft of standard)
July 2012: Draft International Standard
: a( {1 z" a* d  I5 w5 D" b* W4 tJanuary 2013: Final Draft International Standard (ready to be ratified as a Standard)

Where can I find out more?
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JCT-VC Meeting Documents : download JCTVC-C405 for a summary of the HEVC test model HM1.
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November 2010
* c5 c" O" f' }! d0 W2 Y  The Joint Collaborative Team
From the ITU website:
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"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)."

6 q( a: c3 f$ C9 y# s# RTo find out more:

Joint Collaborative Team on Video Coding