Intra Prediction Efficiency and Performance Comparison of

HEVC and VP9Interim Report

Multimedia Processing (EE5359)Shruti Sukumaran

UT ID – 1000870264University of Texas Arlington

Introduction

HEVC – or H.265 – is the direct successor to mpeg4 (H.264) and jointly developed by MPEG and VCEG[6].

VP9 is the successor to VP8 and developed by Google, after they acquired VP8 from On2 Technologies [6]

Is it a Codec War?

AbstractIntra-prediction is one of the main feature -

determines the compression efficiency of the whole codec.

HEVC JCT-VC HM [16] [17] VP9 WebM VP9 encoders[19]Focus on intra frame coding and different

image performance metrics like MSE[23], PSNR ,BD-PSNR [22], bit rate, SSIM[25],Computational Complexity[27] and hence the video quality will be evaluated for high resolution videos.

HEVC

Which is Better?The first thing to say is we are greatly

simplifying these formats, but – despite similar file sizes - initial reports suggest H.265 has higher image quality while VP9 is more reliable for streaming.

The greater prediction modes in H.265 are what give it the edge visually, while VP9 enforces stricter rules on decoding which appears to make streams more consistent and reliable

HEVC ENCODER

HEVC encoder block diagram [11]

HEVC DECODER

HEVC decoder block diagram [11]

HEVC – Intra Prediction

Available prediction directions in the unified intra prediction in HM 1.0 [11]

HEVC intra frame coding

Subdivision of a CTB into CBs [and transform block (TBs)].

Solid lines indicate CB boundaries and dotted lines indicate TB boundaries

(a)CTB with its partitioning(b) Corresponding quad tree[3].

VP9 intra Prediction

Superblock splitting example with solid lines for block split

a) with prediction splitting depicted as dotted linesb) with transform splitting depicted as dotted lines [10]

VP9 Angular Intra Prediction modes [10]

VP9 intra frame Coding

VP9 Intra-prediction [13]

Measurement of Image QualityCriteria to evaluate the compression qualityObjective quality measure- PSNR[22], MSE[23]

Where ‘o’ is the original image and ‘r’ is the reconstructed image. M and N are the width and height of an image and ‘L’ is the maximum pixel value in the NxM pixel image.

M

m

N

n

nmrnmoNM

MSE1 1

2,,*

1

MSE

LPSNR

2

10log10

8/6 VUY PSNRPSNRPSNRPSNRYUV

Video Test Sequences [9]Sequence Resolution Frame Rate(fps)

BlowingBubbles 416x240 30

Cactus 1920x1080 30

Environment SetupHEVC compression efficiency is measured

with HM Test Model.Key-frame compression efficiency estimation

HM encoder is tested in “All Intra – Main” configuration.

Estimation of VP9 performance is carried out with the VPX encoder from The WebM Project - the only implementation of this standard.VP9 Encoder is configures manually.

Blowingbubbles_30fps_416X240

QP QP=22 QP=27 QP=32 QP=37

PSNR(db) 43.839 43.839 42.868 40.992

Bitrate(kbps)

9753.64 7384.384 6861.776 5969.36

Time(sec) 137.60 126.30 104.22 117.48

QP QP=22 QP=27 QP=32 QP=37

PSNR(db) 41.51 37.69 34.38 31.567

Bitrate(kbps)

9227.245 9227.45 8441.844 6992.448

Time(sec) 17.38 14.50 11.94 10.144

VP9

HEVC

BlowingBubbles_30fps_416X240 RD Graph

5000 5500 6000 6500 7000 7500 8000 8500 9000 9500 1000020

25

30

35

40

45

50

HEVCVP9

Bitrate (kbps)

PSN

R(d

b)

Cactus_30fps_1920×1080

QP QP=22 QP=27 QP=32 QP=37

PSNR(db) 41.122 39.123 37.84 33.0641

Bitrate(kbps)

56539.664 40335.68 31092.576 17030.568

Time(sec) 1934.44 1791.77 1754.22 1536.0

QP QP=22 QP=27 QP=32 QP=37

PSNR(db) 41.202 40.567 39.568 36.167

Bitrate(kbps)

55357.09 48748.65 40239.89 17090.58

Time(sec) 1478.92 1392.193 1303.896 1245.952

VP9

HEVC

Cactus_30fps_1920×1080RD Graph

900 10900 20900 30900 40900 5090033

34

35

36

37

38

39

40

41

42

HEVCVP9

So far. . . Future Work

Setup Environment for both codecs- HEVC and VP9

Research the specific parameter set required for “Intra-prediction mode” in both HEVC and VP9.

Collect data- running Test Sequences.

Analyzed how these parameters affect the test sequences with different resolutions.

Trade off Analysis of parameters in VP9 and HEVC.

BD-Bitrate analysis(Bjøntegaard-Delta bit-rate )[29]

Analyse the variation of PSNR with respect to the bit-rate with sequnces of different resolutions.

Analyze difference between codecs - If a constant target quality has to be achieved irrespective of bitrate by varying parameters.

ObservationsDifficult to compare in a fair way

many implementation specific variables - all implementations do not support everything

VP9 only has a 2-pass encoder right now, a basic constant quality mode, but many sophisticated features are not supported yet.

HEVC HM11.0 1-pass, gives best PSNR results in fixed Q mode[28]

List of Abbreviations AVC Advanced Video Coding CABAC Context Adaptive Binary Arithmetic Coder CTB Coding Tree Blocks CTU Coding Tree Units HEVC High Efficiency Video Coding ISO International Organization for Standardization ITU-T International Telecommunication Union -Telecommunication

Standardization Sector JCT-VC Joint collaborative team on video coding JM Joint model software MC Motion Compensation MI Mode Info MPEG Moving Picture Experts Group MSE Mean square error MV Motion Vector NAL  Network Abstraction Layer PSNR Peak signal to noise ratio SSIM Structural similarity index TU Transformation Units TM True Motion VCEG Video Coding Experts Group

References [1]G.Sullivan, J.Ohm, W.Han and T.Wiegand, “Standardized Extensions

of the High Efficiency Video Coding (HEVC) Standard”, Selected Topics in Signal Processing, IEEE Journal of Volume: 7, Issue: 6, Pages: 1001-1016, 2013.

[2]Iain Richardson/Vcodex.com “HEVC An Introduction to High Efficiency Video Coding” 2013

[3]M. Goldman “High Efficiency Video Coding (HEVC) Next Generation Compression technology” SMPTE Vol. 121 No. 5 pages: 27-33, July-August 2012

[4]M.Shafique and J.Henkel “Low Power Design of the Next-Generation High Efficiency Video Coding” IEEE Automation Conference (ASP-DAC), 19th Asia and South Pacific, Pages: 274 – 281, 2014.

[5]D.Grois and D.Marpe “Performance Comparison of H.265/MPEG-HEVC, VP9, and H.264/MPEG-AVC Encoders” IEEE Picture Coding Symposium (PCS) Pages: 394 – 397, 2013.

[6] Access website http://forum.doom9.org/ “How HEVC/H.265 works, technical details & diagrams”

[7] http://forum.doom9.org “How VP9 works, technical details & diagram” [8] D.Mukherjee et al, “The Latest open-source video codec VP9- An

overview and Preliminary results” IEEE Picture Coding Symposium (PCS) Pages: 390 – 393, 2013.

[9] J.Bankoski et al, “Towards a Next Generation Open source Video Codec” SPIE Vol. 8666 Page 2, 2013.

[10]P.Sharabayko et al, “Intra Compression Effciency in VP9 and HEVC” Applied Mathematical Sciences, Vol.7 pp no.137, 6803 – 6824, 2013.

[11] K.R.Rao , D. Kim and J.J. Hwang ,” Video coding standards: AVS China, H.264/MPEG-4 Part10, HEVC, VP6, DIRAC and VC-1"´, Springer, 2014.

[12]Access the website http://www-ee.uta.edu/Dip/Courses/EE5359/ for Thesis Proposal on “Multiplexing/Demultiplexing of main profile of HEVC/H.265 video stream with AAC Audio bit stream, and achieving lip synchronization” Mridula Warrier, 2014.

[13] Access website http://www.webmproject.org/vp9/ PPT on “WebM and the new Open Video Codec” S. Bultje, M.Frost.

[14] Access the website http://www-ee.uta.edu/Dip/Courses/EE5359/ Project on “Implementation and performance analysis of H.264 intra frame”, A.G.Solanki, 2012

[15]A.Grange, Internet draft from Network Working Group “A VP9 Bitstream Overview” August 2013.

[16]HEVC JCT-VC HM reference software https://hevc.hhi.fraunhofer.de/svn/svn_TMuCSoftware/tags/HM-1.0. HM-1.0 [17] F.Bossen, D.Flynn and K.Suhring (July 2011), “HEVC reference

software manual” http://phenix.int-evry.fr/jct/doc_end_user/documents/6_Torino/wg11/JCTVC-F634-v2.zip

[18]JCT-VC documents are publicly available at: http://ftp3.itu.ch/av-arch/jctvc-site, http://phenix.it-sudparis.eu/jct/ .

[19] WEBM-VP9 http://www.webmproject.org/code/, http://git.chromium.org/webm/libvpx.git.

[20] I.Richardson, “H.264 and MPEG-4 video compression: video coding for next generation multimedia”, Wiley 2nd edition, Aug. 2010.

[21]Access the website http://www-ee.uta.edu/Dip/Courses/EE5359/ for Thesis on “Complexity Reduction for VP6 to H.264 Transcoder using motion vector reuse” Jay R Padia, May 2010.

[22]PSNR http://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio. [23]MSE http://en.wikipedia.org/wiki/Mean_squared_error [24]SSIM http://en.wikipedia.org/wiki/Structural_similarity [25]X.Li et al, “Rate-complexity-distortion evaluation for hybrid video

coding” IEEE ICME Pages: 685 – 690, 2010.

[26] H.Schwarz et al “Overview of the Scalable Video Coding Extension of the H.264/AVC Standard” Volume: 17, Issue: 9, Pages: 1103 – 1120, 2007. 

[27]Computational Complexity http://en.wikipedia.org/wiki/Computational_complexity_theory.

[28] Presentation on the Comparison of HEVC and VP9 http://files.meetup.com/Overview.pdf

[29] BD-Bitrate http://en.wikipedia.org/wiki/High_Efficiency_Video_Coding Special Issues on HEVC [30] Special Issue on emerging research and standards in the next generation video

coding , IEEE Transactions on circuits and Systems for Video Technology (CSVT), Vol.22, pp 1646-1909, Dec 2012.

[31]Special Issue on emerging research and standards in the next generation video coding , IEEE Transactions on circuits and Systems for Video Technology (CSVT), Vol.23, pp 2009-2142, Dec 2013

[32]IEEE Journal of Selected Topics in Signal Processing, Vol.7 pp 931-1151 Latest Paper on HEVC [33]H.Zhang and Z. MA, “Fast Intra mode decision for high efficiency video coding

(HEVC)”, IEEE Trans. On CSVT, vol.24, pp. 660-669, April 2014