Fast Motion Estimation Based on Diamond Refinement Search and Mode Decision Algorithm for High Efficiency Video Coding Standard

• Main Authors: Lee-Sheng Lien, 連李勝
• Other Authors: Yeong-Kang Lai
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/uer9up

碩士 === 國立中興大學 === 電機工程學系所 === 106 === With the advancement of science and technology, the demand for high-definition video is constantly increasing both in professional video, online video and daily consumer videos, and HD quality has been fully popularized. With the gradual maturation of 4K technology , will meet the 4K era of higher quality advent. HEVC can support a wide range of video formats from CIF (320 × 288) to HD (1920 × 1080), high resolution 4K (3840 × 2160) and up to 8K UHD (7680 × 4320). The encoding unit is increased from the size of (4 × 4) and (16 × 16) of H.264 to the maximum (64 × 64) to the minimum (8 × 8) of HEVC, and different size blocks are configured according to different requirements. HEVC mainly in three important units, the introduction of a larger coding unit CU (Coding Unit), the prediction unit (Prediction Unit) and the conversion unit (Transform Unit), HEVC compared with H.264 can save 50% of the compression In the video compression, in order to find the matching block with the smallest RD-Cost, the motion estimation often takes a relatively high amount of computation. Therefore, this paper presents a new HEVC algorithm for fast motion estimation and reduces the computational complexity improve compression efficiency. In this paper, a new fast search motion estimation algorithm is proposed contains changes to the three parts of Diamond Refinement Search, Mode Decision, and Inter Prediction Min Block Size. In the diamond refinement search, the motion vector IMV predicted by the AMVP is used as the starting point of the search, the origin zero vector is compared with the IMV, and the smaller RD-Cost is selected as the starting point of the first search, using the first 4 round diamond Search to obtain the minimum RD-Cost position. When the distance between the origin and the best point is not 0 or 1, the distance is determined to be greater than 4. If the distance is greater than 4, the Diamond Refinement Search solution is matched with the Concentric Diamond. Search refines the search; if the distance is less than or equal to 4, use the Small Diamond Search method for a quick search. In the mode selection, using statistics only 2N x 2N Mode, and the highest N x N Mode usage rate, can save the less used Mode, which can greatly accelerate the overall operation time , However, Inter Prediction Min Block Size reduction, the original 8 x 8 is changed to 4 x 4. The original block size can be cut into smaller blocks to improve the image quality after only using 2N x 2N Mode and N x N Mode. Experimental results This paper proposes a high-speed video coding standard fast motion estimation algorithm based on diamond refinement search and mode decision. After adding the Inter Prediction Min Block Size modification, the overall coding time can be saved by 46.15% with a 1.45% increase in Bit-Rate and a -0.03 drop in PSNR.