多媒體通信傳播品質日漸提升，其中高畫質視訊處理技術更是顯著提升，高效率視訊編碼(HEVC/H.265)即為了處理高畫質視頻需求而制定，但也僅支援解析度2K的視訊。最近幾年來已經出現高解析度4K甚至8K的視訊，高解析度的視訊必定是未來發展的主流，因此聯合視訊探索小組(Joint Video Exploration Team, JVET)，從2015年開始招開會議討論新的視訊壓縮標準FVC/H.266(Future Video Coding)，參考軟體為JEM(Joint Exploration Model)，JEM是在HEVC參考軟體HM(HEVC Test Model)的基礎上發展而來，預計在近幾年發布為國際視訊壓縮的標準。
FVC/H.266與HEVC/H.265相比具有更好的編碼效能，相對的編碼架構複雜度也大大的提升，其中最大的不同在於CU(Coding Unit)使用QTBT(Quadtree plus Binary Tree)的區塊編碼結構，在QTBT結構中消除了多個分割類型的概念，即拋棄了CU、PU(Predict Unit)及TU(Transform Unit)分離的概念，提供更靈活的CU分割類型，且支援大小從最小8×8到最大256×256的正方形區塊，甚至一個CU可以有一個正方形或者矩形的形狀，因此編碼時間也大幅增加，在畫面內編碼增加的更是明顯，所以如何在畫面內編碼單位決策中加速，就是要來探討的問題。針對此問題，本論文提出在QTBT結構中參考鄰近深度資訊，利用鄰近LCU( Largest Coding Unit)區塊平均深度來判斷是否適合提前終止(early termination)CU切割的方法。實驗結果顯示，我們所提出的方法，整體而言在BDBR僅上升0.31%的情況下，編碼時間上可以達到25.423%的加速效果，達到降低FVC/H.266運算複雜度之目的。

Multimedia communication has been widely applied by many with the help of high efficient video coding (HEVC) techniques. The HEVC/H.265 now support mostly for 2K video, but 4K and 8K video will become the mainstream in the near future. The JVET started to develop the FVC/H.266 (Future Video Coding) standard for the ultra-high definition video (UHDV) since 2015, whose reference software JEM (Joint Exploration Model) is developed based on the HM (HEVC TestModel).
The FVC/H.266 performs better than the HEVC/H.265 but requires higher time complexity as well. The FVC/H.266 adopts Quadtree plus Binary Tree (QTBT) structure for Coding Units (CU). It eliminates the complex hierarchical decomposition structure among the CU, Prediction Unit (PU) and Transform Unit (TU), in which the block size can be from 8×8 to 256×256. We study how to speed up the FVC/H.266 intra-frame coding process. We proposed to reference the average depth information of neighboring Largest Coding Unit (LCU) to determine whether to early terminate CU decomposition or not. Experiments showed that the proposed method can save up 25.423% of processing time, while the BDBR rises only 0.31%, as compared to the JEM system program.

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