雲端多媒體提供了一種有效率地(Efficient)、有彈性地(Flexible) 及具可延展 (Scalable)的資料處理方式，其對今日使用者對於多媒體之高品質及多樣化之需求提供了一種解決方式。另一方面，隨著智慧型手機及無線網路的普及，使用者不再僅能在家中使用網路服務，他們更可透過行動裝置，便可輕易地取得多媒體訊息，享受無所不在(Ubiquitous)的網路服務。然而對於現今行動串流所存在著有限制的頻寬與對於不同行動裝置之硬體條件所能提供之多媒體服務需求。本研究主要針對在雲端多媒體行動網路串流服務中，其多媒體包含數種串流來源可供選擇時，根據硬體與網路環境等條件，選擇最適當的解析度與位元率來進行串流播放。本研究並設計一套動態串流調整機制，該機制將根據現今串流頻寬的使用及穩定度，動態調整預測頻率及輪詢時間，並針對使用者觀賞品質、硬體條件與硬體運算能力等條件進行評估，並決策出對使用者而言較為適當之多媒體來源，並修正整體多媒體串流撥放序列建構無縫動態轉換播放服務，有效提升整體的播放品質。同時以其行動裝置端之系統觀點來規劃整體平行低功耗設計，並於不破壞原本解碼流程的情況下，根據串流傳輸之即時性考量控管系統多媒體暫存區塊，並透過動態電壓及頻率系統調整系統解碼工作排程時間以減少多媒體資料相依的問題。最後本研究實現此架構雛型以驗證本方法之可行性，根據實驗可發現所提出之方法對於變動之頻寬環境將可提供有效率之動態適應多媒體串流服務。

Cloud multimedia services provide an efficient, flexible, and scalable media processing. It also stands a key solution for high quality and various multimedia services. At the same time, mobile phones become more and more popular, and network technology for users are no longer limited to the home. The users can easily enjoy the ubiquitous multimedia service by using mobile devices. However, the delays and lags resulted from the instability of a mobile network will greatly degrade streaming quality for users. Considering the present limited bandwidth available for mobile streaming and different device requirements, this study presented dynamic adaptive approach that provides multimedia data suitable for a terminal unit environment for mobile streaming services, when there are multiple optional streaming sources in the cloud mobile network, the optimal resolution and bit rate cannot be selected for playing, according to the hardware and network status conditions. And it describes a parallel low-power design on the system level. Under the condition of preserving the original decoding process, we manage the size of the system’s multimedia buffer by considering the spontaneous streaming transfer and tuning the decoding process scheduling time by using the Dynamic Voltage Frequency Scaling (DVFS) system in order to decrease the multimedia data dependency and achieve a multi-core embedded system with accurate and low-power detection mechanism. Finally, this study realized a prototype of this architecture to validate the feasibility of the proposed method. According to the experiment, this method could efficiently improve the overall streaming source sequence to dynamically construct seamless converted play service to effectively upgrade overall streaming quality.

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