High Efficiency Video Coding

masonchung

How Efficient is HEVC?
9 u+ p; ~0 f. v8 {- PThe 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?
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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:
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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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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
+ U3 W. w+ Q& x5 N7 L: }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.
1 _* T) M8 I% T0 t0 ?9 ]( NThe HEVC Test Model
) M  F* T8 j8 F# k  HFollowing 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.

& p2 b) f# E# G  T3 D- b% AWhat's in the Test Model?
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8 K7 H$ e) e, ?5 }3 y% lThe 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
- K/ L, i9 Q- p! x  H& _0 d9 l! MInterpolation: 6- or 12-tap interpolation filter, down to 1/4-sample
Motion prediction: Advanced motion vector prediction
& e. ^# S" q5 Y, q7 R- x6 OEntropy coding: CABAC or Low Complexity Entropy Coding (LCEC)
Loop filter: Deblocking filter or Adaptive Loop Filter (ALF)
Precision: Extended precision options

7 [& O/ G- `5 gMany coding tools have been scheduled for further investigation and may be incorporated into the Test Model if they offer suitable compression gains.
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/ i9 E/ @# A) IHow will it compare to H.264/AVC?
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1 U0 q3 ]# C0 h7 OCurrent 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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5 \+ h0 F. \6 ]- ], [" v7 ?) N1 aWhen will it be finished?

The timescale for completing the HEVC standard is as follows:
1 `: d( v% ^; o8 P0 U. a7 IFebruary 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)

Where 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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November 2010
  The Joint Collaborative Team
. z9 p( Q/ j' p" A. w) R2 H% QFrom 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)."

+ |% v3 {( M! l% B, o) J+ MTo find out more:
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9 w0 R# X" d7 ^& ^, KJoint Collaborative Team on Video Coding