M P E G MPEG 1 Overview 제어인식연구실 이 찬 우 10월 19일 1998년

Overview MPEG Moving Picture Experts Group Known as ISO/IEC Standard , ISO 11172 System, Video, Audio 1.2Mbits/sec, 352 x 240 resolution at 30Hz is often used Video quality is comparable to VHS Random access, GOP(group of pictures) Realtime decoding For storage media; CDROM, DAT(Digital Audio Tape) 2019-05-07 제어인식연구실

MPEG Decoding System MPEG System : Synchronization Video Audio Figure 1 : MPEG Decoding System 2019-05-07 제어인식연구실

MPEG digital video coding Technique Intra-frame coding technique Spatial correlation between nearby pels within same image DCT on image blocks of 8x8 pels Inter-frame coding technique Temporal prediction, motion compensated prediction between frames Sub sampling and Interpolation 4:2:0 format 2019-05-07 제어인식연구실

Intra-frame coding technique DCT Quantize Zigzag scan Figure 2 : Variance distribution of DCT-coefficients Figure 3 : Zigzag scan order 2019-05-07 제어인식연구실

Inter-frame coding technique Block size : 16 x 16 Search Window Motion Vector Figure 4 : Block matching approach for motion compensation 2019-05-07 제어인식연구실

Subsampling and Interpolation The human eye is more sensitive to changes in brightness than to chromaticity changes Divide the images into YUV components 4: 2: 0 format Figure 5 :B picture encoding procedure 2019-05-07 제어인식연구실

Picture type I Picture (Intra) P Picture (Predictive) 프레임 내 부호화 영상 GOP(Group of Pictures)의 독립성 확보 P Picture (Predictive) 프레임간 순방향 예측 부호화 원화상과 같은 순서로 부호화 B Picture (Bi-directionally) 쌍방향 예측 부호화 D Picture DC only, Fast Forward & Fast Rewind 2019-05-07 제어인식연구실

I Picture Figure 6 :I picture encoding procedure 2019-05-07 제어인식연구실

P Picture Figure 7 :P picture encoding procedure 2019-05-07 제어인식연구실

B Picture Figure 8 :Test picture (previous/current/future) Figure 9 :B picture encoding procedure 2019-05-07 제어인식연구실

Picture coding/display order Figure 10 : A group of consecutive pictures in video sequence 2019-05-07 제어인식연구실

Figure 11: (A) Frame at time instance N to be coded. 2019-05-07 제어인식연구실

Figure 11: (B) Frame at instance N-1 used for prediction of the content in frame N (note that the motion vectors depicted in the image are not part of the reconstructed image stored at the encoder and decoder). 2019-05-07 제어인식연구실

Figure 11: (C) Prediction error image obtained without using motion compensation - all motion vectors are assumed to be zero. 2019-05-07 제어인식연구실

Figure 11: (D) Prediction error image to be coded if motion compensated prediction is employed. 2019-05-07 제어인식연구실

MPEG video sequence Figure 12 :MPEG Video sequence Figure 13: Macroblock 2019-05-07 제어인식연구실

Reference 정제창, 그림으로 보는 최신 MPEG, 1997 http://www.image.cityu.edu.hk/~stshchu/project/ProgressReports_1.htm http://wwwam.HHI.DE/mpeg-video/papers/sikora/mpeg1_2/mpeg1_2.htm http://www.c-cube.com/technology/mpeg.html http://bmrc.berkeley.edu/projects/mpeg/faq/mpegfaq.html ISO 13818-2 2019-05-07 제어인식연구실