指導教授：周承復臺灣大學：資訊工程學研究所孫傳煒Sun, Chuan-WeiChuan-WeiSun2014-11-262018-07-052014-11-262018-07-052014http://ntur.lib.ntu.edu.tw//handle/246246/261446隨著大量的異質性手持裝置以及數位影音的廣泛使用，為了要提供不同解析度的影音傳輸要求，Scalable Video Coding (SVC)被設計出來以提供空間，時間或是品質可適性。然而由於手持智慧型裝置有限的計算能力，這些手持裝置並不支援SVC的編碼器，反而絕大多數的影片資訊都被編碼成非可適性的影片格式，例如H.264/AVC ，H.263或是MPEG-2/4等等。在這篇論文當中，我們試圖去設計一個轉碼機制使得H.264/AVC轉碼到H.264/SVC以提供空間可適性，更明確的說，在某些空間層中，我們利用了原本的H.264/AVC編碼模式資訊以決定出一個較小的候選者編碼模式集合。實驗結果顯示出，相比於重新解碼-重新編碼，我們可以達到多達95%編碼時間的減少以及幾乎可忽略的PSNR損失。As huge numbers of heterogeneous devices and digital videos are getting widely used, Scalable Video Coding (SVC) is designed to provide spatial scalability to meet the multi-resolution requirements. Nevertheless, due to limited computing capability, these handheld devices do not support SVC encoder. Instead, most video content is encoded in non-scalable video fashion, e.g. H.264/AVC or H.263, MPEG-2/4, etc. In this work, we try to design a transcoding mechanism from H.264/AVC to H.264/SVC to support spatial scalability requirements. Specifically, we make use of the coding mode information of original H.264/AVC bitstreams together to determine a small set of candidate modes of other layers to speed up the transcoding process. Experimental results show that up to 95% encoding time reduction and almost without PSNR loss can be achieved compared with re-decode and re-encode approach.中文摘要 I Abstract II Content III List of Figures IV List of Tables V Chapter 1. Introduction 1 Chapter 2. Background 6 2.1 Temporal Scalability 6 2.2 Spatial scalability 8 2.2.1 Base_mode_flag 10 2.2.4 Residual_prediction_flag 13 2.2.5 Motion_prediction_flag 14 2.3 Cascaded Pixel Domain Transcoder: 15 2.4 Open-Loop Transcoder 17 2.5 Closed-Loop Transcoder 18 2.6 Motion Vector Refinement 19 Chapter 3. Observations and Motivation 21 Chapter 4. Proposed Schemes 24 4.1 Macroblock Mode-Based Transcoding Scheme 24 4.1.1 Base Layer 25 4.1.2 Intermediate Layer 25 4.1.3 Top Layer 28 4.2 Motion-Based Transcoding Scheme 28 4.2.1 Spatial and Temporal Base Layer 29 4.2.2 Intermediate Layer 30 4.2.3 Top Layer 38 Chapter 5. Experiment Results 40 5.1 Experiment Parameters 40 5.2 Experiment Results 42 Chapter 6. Conclusions 50 References 51724607 bytesapplication/pdf論文使用權限：不同意授權影像轉碼H.264/SVC可適性視訊編碼模式選擇thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/261446/1/ntu-103-R01922119-1.pdf