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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/8891

    Title: 應用於MPEG-4即時視訊平台中以線性模型為基礎的可調適性速率控制機制;SARS : A Linear Source Model Based Adaptive Rate Control Scheme for TCP-friendly Real-time MPEG-4 Video Streaming
    Authors: 張中原;Chung-Yuan Chang
    Contributors: 資訊工程研究所
    Keywords: 即時MPEG-4視訊;可調適性速率控制;線性模型;Real-time MPEG-4 Video;Adaptive Rate Control;Linear Source Model
    Date: 2004-07-01
    Issue Date: 2009-09-22 11:37:11 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 隨著在Internet上或者無線網路中提供視訊串流服務的需求量大增,一個可以幫助視訊串流服務適合於隨時在變動的可用頻寬現制下的可調適性速率控制機制必須要被發展設計出來。隨時在變動的可用頻寬和視訊串流在網路上傳送的延遲時間讓即時視訊串流服務難以達到很高的頻寬使用率,並且也無法提供好的視訊品質給收看的使用者。MPEG-4是目前最被廣為接受採用的一個視訊串流的標準格式,而一個採用MPEG-4來作為視訊編碼解決方案的即時視訊串流系統中必須要提供一個能夠調整視訊壓縮位元率的控制機制來適應這個隨時隨地在改變的網路狀態。 在這篇論文中,我們分析了當一個即時視訊串流服務傳送端採用了TCP-friendly的傳輸協定在Internet中傳送MPEG-4視訊時所產生的問題。而這篇論文主要著重在提供軟體層和壓縮層上問題的解決方案。根據這樣的目標,我們提供了一套解決方案叫做SARS。SARS是一個具有平滑而且可調適性的速率控制機制,而且它包含了三個主要的元件,分別為TFRS模組、LD模組和RSF模組。TFRS模組提供了視訊壓縮時比較平滑的速率,讓產生的視訊畫面間的畫質變動比較小,提供比較平滑的畫質。LD模組可以幫助視訊壓縮時讓壓縮位元率逼近它的目標位元率來減少傳送的延遲時間。RSF模組則提供了一個可調適性的速率控制機制,根據變動的頻寬來分配目標位元率,並且降低了被略過的畫面數目。最後,我們評估了SARS在做CBR和VBR壓縮時的效能,並且也針對不同的TCP-friendly傳輸協定進行模擬實驗。 The increasing demand for streaming video applications on the Internet or wireless motivates the problem of building an adaptive rate control scheme which is adapted to the time-varying network condition. The time-varying available bandwidth and latency make the real-time streaming applications difficult to achieve high bandwidth utilization and video playout rate at receivers. MPEG-4 is now a widely accepted standard streaming format and a video streaming system which encodes the video sequence with MPEG-4 should provide an adaptive rate control mechanism to adapt to these changing conditions. In this thesis we analyze the problem of transmitting MPEG-4 video over IP when senders use a TCP-friendly rate control protocol. This thesis is focused on solving the challenging issues in application layer, compression layer. With this aim, we provide a solution called ”SARS” (Smoothed and Adaptive Rate-control Scheme) in compression layer and application layer for an MPEG-4 video transmission system and discuss the characteristics of each its elements. The SARS contains three main components, including TFRS module, LD module, and RSF module. The TFRS module provides a smoothed rate and helps the video encoder to generate smoothed video quality. The LD module helps the video encoder to meet its target closer and lowers the transmitting delay. The RSF module provides an adaptive rate control scheme, reduces the number of skipped frames, and makes a smoother presentation. The overall performance of SARS will be evaluated in the CBR scenarios or VBR scenarios. We also evaluate the performance of SARS over several rate based congestion control protocols such as RAP, TFRC and TMRC.
    Appears in Collections:[資訊工程研究所] 博碩士論文

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