陳文進臺灣大學：資訊工程學研究所殷圖駿Yin, Tu-ChunTu-ChunYin2007-11-262018-07-052007-11-262018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/53897本論文論述一個可用來評估MPEG-4視訊串流錯誤復原技術的系統發展與實作。這個系統由幾個模組構成：錯誤復原編碼器，錯誤復原轉碼器，錯誤復原解碼器，優先權式錯誤保護編碼器，優先權式錯誤保護解碼器，以及網路錯誤模擬器。無線網路在網路層可能產生三種不同的錯誤型態，包括：封包遺失錯誤、隨機錯誤、以及連續錯誤。網路錯誤模擬器只要設定適當的組態參數，就可以模擬不同網路的錯誤模型，進而幫助我們評估不同錯誤復原技術在不同網路的效能。為了讓MPEG-4視訊串流可以在高錯誤率的無線網路上平順的傳輸，我們提出了一個錯誤復原策略。這個策略整合三個在這篇論文中新提出的錯誤復原技巧，分別是優先權式錯誤保護機制、資料分隔保護技術以及Intra修補技術。此外，這個策略還整合三個MPEG-4標準中所定義的錯誤復原工具，分別是視訊封包結構、延伸標頭碼以及NEWPRED。解碼器實作了一個對傳輸錯誤具有高度敏銳度的錯誤偵測機制。此外，有三個錯誤隱藏技術在解碼器這邊實作出來，分別是時域取代法、移動向量取代法、以及估測式移動向量取代法。最後，我們利用WCDMA網路的組態設定，來評估我們所提出的錯誤復原策略的整體效能。WCDMA網路是下一代行動通訊協定，它的主要應用之一就是視訊串流。實驗結果顯示，在高錯誤率的WCDMA無線網路進行視訊傳輸並且不增加太多額外頻寬負擔的情況下，視訊品質成它a被保護在可接受的範圍內。An MPEG-4 video error resilient evaluation system is developed in this thesis. The system comprises an error-resilient encoder, an adaptive error-resilient transcoder, an error-resilient decoder, a network error simulator, a PLBP encoder and a PLBP decoder. Wireless channels may cause three types of error in the output of network layer, namely packet loss error, random error and burst error.　With appropriate configuration set on the network error simulator, performance of various error-resilient techniques can be evaluated over the simulated wireless channel. To facilitate MPEG-4 video communication over error-prone wireless channel, an Error-Resilient Strategy is proposed in this thesis. In order to provide protection on the MPEG-4 bitstream, the ER strategy integrates three proposed novel error resilient techniques, namely Prioritized-Level Bitstream Protection (PLBP), Protected Data Partitioning (PDP) and Restorative Intra Adoption (RIA), and, in addition, error resilience tools defined in MPEG-4 video standard, namely Video Packet Structure, Header Extension Code (HEC) and NEWPRED. In the decoder side, three error concealment techniques are implemented in the decoder, namely Temporal Replacement, Motion Replacement, and Predictive Motion Replacement. The decoder also implements a powerful error detection mechanism that has high sensitivity to detect errors. Finally, the performance of the proposed ER strategy is evaluated in the system with WCDMA configuration. WCDMA is the next generation mobile communication protocol and one of its killer-application is video streaming. The experimental results show that in error-prone conditions of WCDMA network, acceptable video quality is successfully retained without incurring much overhead.致 謝 3 摘 要 5 ABSTRACT 7 CHAPTER 1 INTRODUCTION 17 1.1 BACKGROUND 18 1.2 MOTIVATION 20 CHAPTER 2 ERROR MODEL OF WCDMA NETWORKS 23 2.1 OVERVIEW 23 2.2 WCDMA RADIO INTERFACE CHARACTERISTICS 24 2.3 ERROR MODEL OF WCDMA NETWORKS 30 CHAPTER 3 MPEG-4 VIDEO CODING STANDARD 33 3.1 FUNCTIONALITIES AND APPLICATION SCENARIOS 33 3.2 HIERARCHICAL STRUCTURE OF CODED BITSTREAM 34 3.3 CODING ALGORITHMS AND TECHNIQUES 35 3.3.1 Hybrid DPCM / DCT Transform Coding 35 3.3.2 Motion-Compensated Prediction 36 3.3.3 Transform Domain Coding 37 3.3.4 Temporal Predictive Coding 38 3.3.5 Quantization 39 3.3.6 AC/DC Prediction 39 3.3.7 Motion Estimation 41 3.3.8 Predictive Motion Vector Coding 43 3.3.9 Zig-Zag, Run-length and Huffman Coding 45 3.4 VULNERABILITY OF MPEG-4 CODED BITSTREAM 46 3.4.1 Visual Object Sequence Header 46 3.4.2 Visual Object Header 47 3.4.3 Video Object Layer Header 48 3.4.4 Group of VOP Header 52 3.4.5 Video Object Plane Header 53 3.4.6 Macroblock 55 3.4.7 block 58 3.4.8 Video Packet Header 58 3.4.9 Video Packet with data partitioned 59 CHAPTER 4 AN ERROR RESILIENT CODING STRATEGY 61 4.1 THE ERROR RESILIENT STRATEGY 61 4.2 ERROR RESILIENT TECHNIQUES 64 4.2.1 Video Packet Structure 66 4.2.2 Protected Data Partitioning 69 4.2.3 Header Extension Code 72 4.2.4 Adaptive Intra Refresh 73 4.2.5 New Predictive VOP Adoption 73 4.2.6 Prioritized-Level Bitstream Protection 75 CHAPTER 5 IMPLEMENTATION OF A HYBRID AND ADAPTIVE ERROR RESILIENCE EVALUATION SYSTEM 81 5.1 SYSTEM ARCHITECTURE 81 5.2 NETWORK ERROR SIMULATOR 83 5.3 THE ERROR RESILIENT ENCODER 84 5.4 PLBP ENCODER/DECODER 86 5.5 THE ERROR RESILIENT TRANSCODER 88 5.6 THE ERROR RESILIENT DECODER 90 CHAPTER 6 EXPERIMENTS AND RESULTS 93 6.1 EXPERIMENT 1 93 6.2 EXPERIMENT 2 95 6.3 EXPERIMENT 3 96 6.4 EXPERIMENT 4 97 CHAPTER 7 CONCLUSION AND FUTURE WORKS 99 BIBLIOGRAPHY 1011118296 bytesapplication/pdfen-US高錯誤率無線網路串流錯誤復原技術MPEG-4WCDMAError-Resilientthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/53897/1/ntu-93-R91922057-1.pdf