- By Naveen Siddaraju - Under the guidance of Dr K R Rao Study and comparison of H.264/MPEG4 part10 AVC main profile with AVS P2 Jizhun profile

Contents Introduction Brief overview of H.264 Brief overview of AVS China Comparison Results Conclusion Future work

Introduction

H.264 / MPEG 4 AVC Latest video coding standard Basic design architecture is similar to previous MPEG standards Better compression efficiency

Coding structure Picture  slices  MBs  subMBs  blocks  pixels I, P and B slices Derived slices SI and SP

Different YUV systems in H.264 [16]

Profiles and levels in H.264 Baseline profile Main profile Extended profile High profiles

H.264 Profiles – coding parts [1]

Intra prediction in H.264 Uses adaptive spatial prediction to reduce spatial redundancy. 4 X 4 luma, 8X8 luma( used in high profile) – 9 modes 16 X 16 luma – 4 modes 4 X 4 chroma - 4 modes

H.264 intra prediction modes for 4X4 luma

H.264 inter prediction Uses motion estimation and motion compensation (MC). Used to reduce temporal correlation.

H.264 encoder [1]

H.264 decoder [1]

De-blocking filter Is used to reduce the blocking artifacts. Two sources of the blocking arifacts. - 4 X 4 transform - motion compensated prediction since the filter is present in the loop, it prevents the propagation of the blocking artifacts.

Entropy coding quantized values and other syntax elements into actual bits. CAVLC and CABAC for quantized coefficients. Exp- Golomb codes for syntax elements which are not coded by CABAC or CAVLC.

AVS – China Latest audio video coding standard from China Standardization includes system, audio, video and digital copyright management. Goal – to achieve coding efficiency with reduced complexity.

AVS Parts [3]

AVS layered data structure [3] for 4:2:0 video sequence

AVS video - profiles Jizhun profile (base profile) Jiben profile (basic profile) Shenzhan profile (extended profile) Jiaqiang profile (enhanced profile)

AVS P2 encoder [ 24]

AVS decoder

AVS motion estimation and intra prediction : AVS uses adaptive modes for motion compensation at the picture layer and the macroblock layer. The modes in picture layer are : Forward prediction from the most recent reference frame Forward prediction from the second most recent prediction frame Interpolative prediction between the most recent reference frame and a future reference frame. Intra coding

AVS motion estimation and intra prediction (cont..) At the macroblock layer, the modes depend on the picture mode. In Intra pictures, all macroblocks are intra coded. In Predicted pictures, macroblocks may be forward predicted or intra coded. In interpolated pictures, macroblocks may be forward predicted, backward predicted, interpolated or intra coded.

Predicted pictures (P – pictures):

Interpolated Pictures (B-Pictures):

AVS intra prediction [7]

Comparison H.264 and AVS video

Rate control Block: A rate control algorithm dynamically adjusts encoder parameters to achieve a target bitrate. quantization parameter QP quantization parameter

Encoder with and without rate control block

Bitrate Vs QP

Standards for representing digital video

results: H.264 – JM 16.1 used [9] AVS – RM09.01[10]

JM 16.1 output

AVS ref software output

Input sequence : QCIF Foreman [10] : Bitrates Vs psnr

Plot: PSNR vs. bit rate

Sequence: QCIF car phone [10]

CIF: Foreman sequence [10]

CIF football sequence [10]

4CIF: sequence ( 704 X 576) [20]

Conclusion H.264 always gives better coding efficiency and compression. Advantages of AVS: - Faster encoder - Reduced complexity - reduced costs. Performance difference is mainly due to absence of complex tools such as CABAC and fewer prediction modes.

Future work: comparison between other profiles like extended profiles of AVS and AVC. Comparison between h.264 and other codecs like wmv9 (windows media video), RV10 (real video) etc.

List of acronyms used

Thank you

References [1] Soon-kak Kwon et al. “Overview of H.264 / MPEG-4 Part 10 (pp )”, Special issue on “ Emerging H.264/AVC video coding standard”, J. Visual Communication and Image Representation, vol. 17, pp , April [2] A. Puri et al. “Video coding using the H.264/MPEG-4 AVC compression standard”, Signal Processing: Image Communication, vol.19, pp , Oct [3] W. GAO et al. “AVS - The Chinese next-generation video coding standard” NAB, Las Vegas, [4] X. Wang et.al “Performance comparison of AVS and H.264/AVC video coding standards” J. Comput. Sci. & Technol., Vol.21, No.3, pp J, May [5] L. Yu et al. “An Overview of AVS-Video: tools, performance and complexity”, Visual Communications and Image Processing 2005, Proc. of SPIE, vol. 5960, pp , July 31, [6] D Chang “MPEG 4, H.264 compression standards” ppt, [7] L. Yu et al. “An area-efficient VLSI architecture for AVS intra frame encoder” Visual Communications and Image Processing 2007, Proc. of SPIE-IS & T Electronic Imaging, SPIE vol. 6508, pp , Jan. 29, 2007.

[8]Introduction to codecs: knowhttp://gizmodo.com/ /giz-explains-every-video-format-you-need-to- know [9] H.264/AVC JM Software suehring/tml/download new version of the H.264/AVCreference software [10] AVS reference software, ftp:// /public/avs_docs/avs_software. ftp:// /public/avs_docs/avs_software [11] MPEG website: [12]MPEG-1: ISO/IEC JTC1/SC29, Coding of moving pictures and associated audio for digital storage media up to about ARTICLE IN PRESS A. Puri et al. / Signal Processing: Image Communication 19 (2004) 793– Mbit/s, ISO/IEC , International Standard, November [13] MPEG-2: ISO/IEC JTC1/SC29/WG11 and ITU-T, ISO/IEC : Information Technology- Generic Coding of Moving Pictures and Associated Audio Information: Video, ISO/IEC and ITU-T,1994. [14] MPEG-4: ISO/IEC JTCI/SC29/WG11, ISO/IEC :2000-2: Information on Technology-Coding of Audio-Visual Objects-Part 2: Visual, ISO/IEC, 2000.

[15] H.264 Standard 2007.pdf, [17] JVT ”Draft ITU-T recommendation and final draft international standard of joint video specification (ITU-T rec. H.264– ISO/IEC AVC),” March 2003,JVT-G050 available on [18] R. Schäfer, et al, “The emerging H.264/AVC standard”, EBU Technical Review, Jan [19] Rate Control and H.264, link: [20] UTA digital image processing course website, link: ee.uta.edu/dip/Courses/EE5356/ee_5356.htmhttp://www- ee.uta.edu/dip/Courses/EE5356/ee_5356.htm [21] H.264/ AVC Reference Software Manual link: AE010%29.pdf AE010%29.pdf [22] T. Wiegand, et al, “Overview of the H.264/AVC Video Coding Standard” IEEE Trans.Circuits and Systems for Video Technology, vol. 13, pp , June 2003.

[23] AVS Video Expert Group, “Information Technology – Advanced coding of audio and video – Part 2: Video (AVS1-P2 JQP FCD 1.0),” Audio Video Coding Standard Group of China (AVS), Doc. AVS-N1538, Sep [24] Lu Yu et al, “Overview of AVS-video coding standards”, special issue on “Special issue on AVS and its applications” J. Visual Communication and Image Representation, Volume 24, Issue 4, April 2009, Pages Volume 24, Issue 4