High Efficiency Video Coding

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How Efficient is HEVC?
) U9 d; P/ q& C! k* a# R! hThe 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:
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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).
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* q' J9 C# u9 x0 h$ J/ WThis 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
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
. o2 p' P7 o8 d1 X2 N! [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.

" s! O9 t( q, b+ D) T( ]( PWhat's in the Test Model?

The main components are as follows:
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$ t! Q* p" D3 Q' L" t. V; b- ~$ XCoding unit: Block sizes from 8x8 to 64x64 in tree structure
Transform: Quadtree structured block size from 4x4 to 32x32 samples
) K  _5 G4 {) T6 f+ G0 h" G* FIntra prediction: Up to 34 intra prediction directions
2 d4 |6 ~6 q# t# M$ z& T% nInterpolation: 6- or 12-tap interpolation filter, down to 1/4-sample
Motion prediction: Advanced motion vector prediction
7 n! W: @$ j9 G5 F/ {3 ZEntropy coding: CABAC or Low Complexity Entropy Coding (LCEC)
7 ~2 @! e' W. u# L' pLoop filter: Deblocking filter or Adaptive Loop Filter (ALF)
" J% n" Z0 U- q8 r' TPrecision: Extended precision options
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: G& F# T6 a/ j  T; P/ \Many 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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How will it compare to H.264/AVC?
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& H/ o4 [" I1 H8 T/ WCurrent 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.

; }' @, {/ \$ ^7 x+ \' U- sWhen will it be finished?
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; r; y9 X6 j0 wThe timescale for completing the HEVC standard is as follows:
; I. \3 N- L8 _: u' V! O! ZFebruary 2012: Committee Draft (complete draft of standard)
$ d' [) B0 \" N4 k; K9 uJuly 2012: Draft International Standard
1 `5 U8 I" T$ I1 L- K6 [5 AJanuary 2013: Final Draft International Standard (ready to be ratified as a Standard)
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) Z& w/ `% s, `) }* k# B' dWhere 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
+ p7 Q1 L( S* d: ^  k6 R- w  The Joint Collaborative Team
From the ITU website:
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' v) _5 {8 _0 e8 |# r"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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0 T+ Y+ ^& |* E0 H! N8 ~To find out more:

Joint Collaborative Team on Video Coding