Overview of AVS Video Standard Kai-Chao Yang

Outline Audio Video Coding Standard (AVS) Audio Video Coding Standard (AVS) AVS Schedule AVS Schedule AVS Architecture AVS Architecture Difference between AVS, H.264/AVC, and MPEG-2 Difference between AVS, H.264/AVC, and MPEG-2 Performance Performance Reference Reference

Audio Video Coding Standard (AVS) - 1/2 Developed by Audio Video Coding Standard Working Group (June, 2002). 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 ) 1 st version of AVS video standard has been finished on December st version of AVS video standard has been finished on December Ratified as the national standard of China on March 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 Focus on high definition and high quality videos Four main technical standards Four main technical standards –System, video, audio, and DRM Features Features – 自主知识产权 RMB 1 dollar for each AVS decoder RMB 1 dollar for each AVS decoder –Backward compatible with MPEG-2 Latest meeting Latest meeting –June 7-11, 2006 –Two new working groups FG-IPTV working group FG-IPTV working group MPEG-C working group MPEG-C working group

AVS Schedule Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3Q 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 Mobile Multimedia AVS-M Video Stage 1 AVS-M Video Stage 2

AVS Architecture - 1/8 Intra Prediction ICT/Q Q -1 /ICT -1 Entropy coding Loop Filter Frame Buffers ME MC Video

AVS Architecture - 2/8 8x8 integer transform 8x8 integer transform Four types of block sizes Four types of block sizes –16x16, 16x8, 8x16, 8x8 ¼ -pel motion estimation ¼ -pel motion estimation Scanning order Scanning order –Progressive and interlacing Adaptive VLC Adaptive VLC –Four types of Exp-Golomb codebooks In-loop deblocking filter In-loop deblocking filter –Automatically adjusted depending on block types, MVs, and QPs 4:2:0 and 4:2:2 8-bit sampling 4:2:0 and 4:2:2 8-bit sampling Weighted prediction Weighted prediction

AVS Architecture - 3/8 16-bit 8x8 integer transform 16-bit 8x8 integer transform – Y = T  ((X  T t + 4) >> 3) y ij  [-2 15, ] y ij  [-2 15, ] – (y ij ) >> 7 Quantization Quantization – x ij = (x ij ’  a(QP) + 2 s(QP)-1 ) >> s(QP) a(QP): inverse quantization table a(QP): inverse quantization table s(QP): shift value s(QP): shift value Guarantee 16-bit

AVS Architecture - 4/8 Intra Prediction Intra Prediction –8x8 luma block 5 prediction modes 5 prediction modes –8x8 chroma block 4 prediction modes 4 prediction modes

AVS Architecture - 5/8 Reference pictures of P-pictures 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 Reference pictures of B-pictures –Four modes Direct Direct Forward Forward Backward Backward Symmetrical Symmetrical –Only one MV is recorded ? nn+1n-1

AVS Architecture - 7/8 Interlacing Coding Interlacing Coding nn+1 Field 1 Field 2

AVS Architecture - 8/8 Profiles and Levels Profiles and Levels –Jizhun Profile For SD/HD broadcast and storage For SD/HD broadcast and storage Containing all techniques in AVS except the Advanced Prediction Mode Containing all techniques in AVS except the Advanced Prediction Mode –Advanced Profile? –Four levels From 720x576 to 1920x1080 From 720x576 to 1920x1080 From 10 Mbps to 30 Mbps From 10 Mbps to 30 Mbps

Difference between AVS, H.264/AVC, and MPEG-2 - 1/2 ToolsAVSH.264/AVCMPEG-2 Intra prediction 8x8; 5 modes for luma and 4 modes for chroma 4x4; 9 modes for luma and 4 modes for chroma DC prediction Reference frames 2222  16 1 Block size 16x16, 16x8, 8x16, 8x8 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, 4x4 16x16, 16x8 for interlace B-frame prediction Coding front MV and computing back MV Coding two MVs

Difference between AVS, H.264/AVC, and MPEG-2 - 2/2 ToolsAVSH.264/AVCMPEG-2 Sub-pel MC 4-tap ½ -pel MC 4-tap ¼ -pel MC 6-tap ½ -pel MC 2-tap ¼ -pel MC 2-tap ½ -pel MC Transform and quantization 8x8 integer transform 4x4 and 8x8 integer transform 8x8 float DCT Loop filter 8x8 based; bS level from 0 to 2; filtered pels (p0, p1, q0, q1) 4x4 based; bS level from 0 to 4; filtered pels (p0..p3, q0..q3) N/A

Performance – HD (1280x720) Higher Bitrate

Performance – HD (1280x720) Lower Bitrate

Performance – SD (720x576) Higher Bitrate

Performance – SD (720x576) Lower Bitrate

Performance – CIF (352x288) Higher Bitrate

Performance – CIF (352x288) Lower Bitrate

Reference Wen Gao, “ AVS – A Project Towards to an Open and Cost-Efficient Chinese Nation Standard, ” ITU-T VICA Workshop, July Wen Gao, “ AVS – A Project Towards to an Open and Cost-Efficient Chinese Nation Standard, ” ITU-T VICA Workshop, July Liang Fan, Siwei Ma, and Feng Wu, “ Overview of AVS Video Standard, ” IEEE International Conference on Multimedia and EXPO, Liang Fan, Siwei Ma, and Feng Wu, “ Overview of AVS Video Standard, ” IEEE International Conference on Multimedia and EXPO, AVS Working Group ( AVS Working Group (