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Overview of AVS Video Standard. Kai-Chao Yang. Outline. Audio Video Coding Standard (AVS) AVS Schedule AVS Architecture Difference between AVS, H.264/AVC, and MPEG-2 Performance Reference. Audio Video Coding Standard (AVS) - 1/2.
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Overview of AVS Video Standard Kai-Chao Yang
Outline • Audio Video Coding Standard (AVS) • AVS Schedule • AVS Architecture • Difference between AVS, H.264/AVC, and MPEG-2 • Performance • Reference
Audio Video Coding Standard (AVS) - 1/2 • Developed by Audio Video Coding Standard Working Group (June, 2002). • Science and Technology Department of the China Ministry of Information Industry (国家信息产业部科学技术司) • 1st version of AVS video standard has been finished on December 2003. • Ratified as the national standard of China on March 2006.
Audio Video Coding Standard (AVS) - 2/2 • Focus on high definition and high quality videos • Four main technical standards • System, video, audio, and DRM • Features • 自主知识产权 • RMB 1 dollar for each AVS decoder • Backward compatible with MPEG-2 • Latest meeting • June 7-11, 2006 • Two new working groups • FG-IPTV working group • MPEG-C working group
Q1 Q1 Q1 Q1 Q1 Q2 Q2 Q2 Q2 Q2 Q3 Q3 Q3 Q3 Q3 Q4 Q4 Q4 Q4 Q4 AVS Schedule High Definition / Standard Definition Digital TV Broadcasting and Optical Storage Media Applications AVS-1.0 Video Jizhun Profile AVS-1.0 System AVS-1.0 Audio AVS Advanced-profile AVS-M Video Stage 1 Mobile Multimedia AVS-M Video Stage 2 2004 2005 2006 2002 2003
AVS Architecture - 1/8 Intra Prediction Entropy coding ICT/Q Q-1/ICT-1 MC Frame Buffers Loop Filter Video ME
AVS Architecture - 2/8 • 8x8 integer transform • Four types of block sizes • 16x16, 16x8, 8x16, 8x8 • ¼-pel motion estimation • Scanning order • Progressive and interlacing • Adaptive VLC • Four types of Exp-Golomb codebooks • In-loop deblocking filter • Automatically adjusted depending on block types, MVs, and QPs • 4:2:0 and 4:2:2 8-bit sampling • Weighted prediction
AVS Architecture - 3/8 • 16-bit 8x8 integer transform • Y = T ((X Tt + 4) >> 3) • yij [-215, 215-1] • (yij + 26) >> 7 • Quantization • xij = (xij’ a(QP) + 2s(QP)-1) >> s(QP) • a(QP): inverse quantization table • s(QP): shift value Guarantee 16-bit
AVS Architecture - 4/8 • Intra Prediction • 8x8 luma block • 5 prediction modes • 8x8 chroma block • 4 prediction modes
AVS Architecture - 5/8 • Reference pictures of P-pictures • In MPEG-1 and MPEG-2, only one reference picture is allowed, but the buffer size should be two pictures. • In AVS, two previous adjacent pictures can be used as reference.
AVS Architecture - 6/8 • Reference pictures of B-pictures • Four modes • Direct • Forward • Backward • Symmetrical • Only one MV is recorded ? n-1 n n+1
AVS Architecture - 7/8 • Interlacing Coding Field 1 Field 2 n n+1
AVS Architecture - 8/8 • Profiles and Levels • Jizhun Profile • For SD/HD broadcast and storage • Containing all techniques in AVS except the Advanced Prediction Mode • Advanced Profile? • Four levels • From 720x576 to 1920x1080 • From 10 Mbps to 30 Mbps
Reference • Wen Gao, “AVS – A Project Towards to an Open and Cost-Efficient Chinese Nation Standard,”ITU-T VICA Workshop, July 2005. • Liang Fan, Siwei Ma, and Feng Wu, “Overview of AVS Video Standard,”IEEE International Conference on Multimedia and EXPO, 2004. • AVS Working Group (http://www.avs.org.cn/)