1 / 16

Time Optimization of HEVC Encoder over X86 Processors using SIMD

This study focuses on optimizing the time efficiency of the High Efficiency Video Coding (HEVC) encoder on X86 processors by leveraging Streaming SIMD Extensions (SSE) instructions. With the goal of achieving significant bit-rate reductions while maintaining perceptual video quality, the HEVC standard poses increased computational complexity, impacting encoding speed. By exploring the use of SIMD instructions, particularly SSE, the study aims to enhance the processing speed of the HEVC encoder. The text delves into the block diagram of the encoder, time analysis of HEVC encoding, macroblocks in HEVC, motion estimation techniques, and the role of SIMD instructions for motion compensation. By utilizing SSE instructions, such as PMADDUBSW and PMADDW, parallel processing capabilities are harnessed to streamline motion compensation calculations. The study also explains how SIMD allows for operating on multiple data simultaneously, thereby accelerating motion estimation tasks. With an overview of SSE instructions and their applications, this research sheds light on optimizing the time efficiency of HEVC encoding on X86 processors.

keiki
Download Presentation

Time Optimization of HEVC Encoder over X86 Processors using SIMD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Time Optimization of HEVC Encoder over X86 Processors using SIMD Spring 2013Multimedia Processing EE5359 Advisor: Dr. K. R. Rao Kushal Shah 1000857252 kushal.shah7@mavs.uta.edu

  2. Objective • With a lot of enhanced coding tools introduced, HEVC is expected to achieve 50% bit rate reductions at similar mean opinion score (MOS) compared with the previous standard H.264/AVC. • However, the computational complexity of HEVC has greatly increased, making encoding speed a serious problem in the implementation of HEVC.[2]

  3. Overview of HEVC[1] • High Efficiency Video Coding (HEVC) is the newest video coding standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. • The main goal of the HEVC standardization effort is to enable significantly improved compression performance relative to existing standards—in the range of 50% bit-rate reduction for equal perceptual video quality.

  4. Encoder Block Diagram[1]

  5. Macroblocks in HEVC[5]

  6. Time Analysis of HEVC Encoder[2][3]

  7. Time Analysis of HEVC Encoder[2][3] • HEVC utilizes a quadtree structure [4] to support large and flexible block sizes. • The size of a coding unit (CU) can be 64x64, 32x32, 16x16 and 8x8. Each CU is split into one or more prediction units (PU) and transform units (TU). • For PU, the width and height of a PU varies from 4 to 64, indicating that the blocks to be processed in motion compensation (MC) can be as large as 64x64.

  8. Time Analysis of HEVC Encoder[2][3] • In motion estimation (ME), sum of absolute differences (SAD) and sum of absolute transformed differences (SATD) of different block sizes are calculated. • Due to the flexible block structure, each 4x4 block will be calculated several times from 4x4 to 64x64 ME, which can be quite time-consuming.

  9. Motion Compensation • 8-Tap Interpolation Filter:

  10. Intel SSE Instruction[6] • Streaming SIMD Extensions (SSE) is the SIMD instruction set extension over the x86 architecture. It is further enhanced to SSE2, SSE3, SSSE3 and SSE4 subsequently. • SSE contains eight 128-bit registers originally, known as XMM0 through XMM7. And the number of register is extended to sixteen in AMD64. • Each 128-bit register can be divided into two 64-bit integers, four 32-bit integers, eight 16-bit short integers or sixteen 8-bit bytes. • With SSE series instructions, several XMM registers can be operated at the same time, indicating considerable data-level parallelism.

  11. Intel SSE Instruction[6] • The PMADDUBSW instruction takes two 128-bit SSE registers as operands, with the first one containing sixteen unsigned 8-bit integers, and the second one containing sixteen signed 8-bit integers. With this instruction, we only need to sum the values in the result register to get the final results.

  12. Intel SSE Instruction[6] • The PMADDW instruction takes two 64-bit SSE registers as operands, with the first one containing eight unsigned 8-bit integers, and the second one containing eight signed 8-bit integers. This instruction adds and concatenates values of this two operands.

  13. Calculating MC Vectors

  14. Abbreviation • SIMD : Single Instruction Multiple Data • ME: Motion Estimation • SAD: Sum of Absolute Differences • SATD: Sum of Absolute Transformed Differences (SATD) • CTU: Coding Tree Unit • CB: Coding Block • PB: Prediction Unit • TB: Transform Unit

  15. References [1] G. J. Sullivan, J.-R. Ohm, W.-J. Han, and T. Wiegand, “Overview of the High Efficiency Video Coding (HEVC) standard,” IEEE Trans. Circuits Syst. Video Technol., vol. 22, no. 12, pp. 1648–1667, Dec. 2012. [2] Keji Chen, YizhouDuan, Leju Yan, Jun Sun and ZongmingGuo, “Efficient SIMD Optimization of HEVC Encoder over X86 Processors ,” Institute of Computer Science and Technology, Peking University, Beijing 100871, China. [3] JCT-VC, “HM6: High Efficiency Video Coding (HEVC) Test Model 6 Encoder Description,”JCTVC-H1002, Feb. 2012. [4] D. Marpe et al., “Video compression using nested quadtree structures, leaf merging, and improved techniques for motion representation and entropy coding,” IEEE Trans. Circuits Syst. Video Technol., vol. 20, no. 12, pp. 1676 –1687, Dec. 2010. [5] http://codesequoia.wordpress.com/2012/10/28/hevc-ctu-cu-ctb-cb-pb-and-tb/ [6] Intel Corp., Intel® 64 and IA-32 Architectures Software Developers Manual

  16. THANK YOU

More Related