A Low Complexity Intra Texture Coding Algorithm and Architecture Design for H.264 Video Coding Targeting at HDTV Applications
| Autor: | Yi-Huan Ou Yang, 歐陽亦桓 |
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| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 In H.264 video standard, intra coding is one of the most important components to increase the data compression ratio, and it also accompanies lots of computation complexity. Mode decision has the largest portion of computation in H.264 intra coding. There are still not many search algorithms of mode decision at present. In this thesis, we propose a new search algorithm and architecture design of H.264 intra texture coder targeting on HDTV applications. First, in the system architecture design, the complexity of intra coding system is analyzed. We target at mode decision and try to optimize it. We utilize the spacial correlation and smooth variation in real image. Then we propose three search methods including all the prediction cases and have implemented them in H.264 reference software JM 9.3. The proposed methods contain condition-correlation search, half-full search, and context-correlation search. The experimented result shows that the proposed methods can reduce 43% of computational complexity in Intra4x4 prediction modes as 26% in system and keep the PSNR degraded by only 0.01 dB. Then we measure the amount of computation and decide the parallelism of the intra frame coding system according to the different computational complexity between mode decision and texture coding loop. We also modify some operating algorithms of intra frame coder to make hardware design efficient. The proposed algorithms contain exchanging IQ/IT routine and simplifying chroma DC transform. Then the proposed frame coder architecture is proposed with the former properties, and a texture decoder for our H.264 decoder is also proposed according to the system requirements. The proposed intra frame coder for H.264 video encoding and texture decoder for H.264 video decoding both have lower hardware cost than the existing designs. Comparing the proposed intra frame coder with others from the rate-distortion curves, we indicate that the proposed intra frame coder possesses the better performance in terms of the data quality and computational complexity than the other designs. The proposed hardware design can achieve the real-time processing for H.264 video decoding targeting at HD1080i format video@30Hz and H.264 video encoding targeting at HD720p format video@30Hz. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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