Android自2007年由Google釋出以來，以開放式原始碼應用於各種嵌入式平台之上，Android-based相關產品也如雨後春筍般林立，如手機、機上盒等行動裝置，目前Android的發展受到各界矚目，將成為未來嵌入式系統研究主流。

本研究於TI OMAP3530硬體平台之上建置Android嵌入式作業系統，並設計一可運行於DSP之上的多媒體播放處理環境，以提升多媒體服務之品質，並導入省電機制進行電源管控以提升手持裝置的續航力。本研究系統架構包含：開放性的Android作業系統平台、DSP多媒體播放環境建置、多媒體串流影音服務、Android 電能控管機制等四大研究主軸。

本研究以Android 2.1作業系統、DVSDK多媒體框架以及0xLab所釋出的0xdroid開放式原始碼作為基礎。根據OMAP-3530之硬體平台規範，修改Android所需之環境變數，進而將Android系統掛載於OMAP-3530平台之上。並結合DVSDK多媒體開發模組，建構本案所提出的Android/DVSDK多媒體運作環境，藉由DSP數位訊號處理器，提升多媒體檔案編、解碼速率，提供使用者高品質的多媒體播放服務。系統功能包含接收來自伺服器的多媒體串流，進行影音編、解碼服務，並將處理完畢的封包傳送至使用者端進行播放。另一方面，隨著使用者對手持裝置的多媒體服務需求的增長，手持裝置電源的續航力將成為嵌入式系統發展的重要議題。本研究將Dynamic Voltage and Frequency Scaling省電機制導入於本案所建置的Android/DVSDK系統中，根據系統運作情形，動態調控ARM 及DSP工作頻率，並針對無須使用到的硬體電源裝置進行管控。透過本研究所提出之多媒體播放架構，每秒處理畫面可由原本的24 Frame Per Second提升至28 Frame Per Second，並降低1.5%的電能消耗，實現高品質多媒體播放環境及電源有效利用之目標。

Since Google released Android source code in 2007, on the market, Android based product implementation has increased rapidly on digital converged devices such as mobile phone, set-box, etc. Obviously Android System development is broadly attracting ICT industry sectors, as in the future, Android will keep continue its domination on embedded system technology.

This study proposed an Android/DVSDK platform by embedding Android version 2.1 on TI OMAP-3530 and designing a Multimedia service system based on Digital Signal Processor. It achieves two main functions simultaneously: a high quality multimedia service and power saving control mechanism to extend hand-held device life-time simultaneously for multimedia streaming server application.

On the implementation, this study combines Android System, Digital Video SDK module and 0xlab release Android open source code base on the OMAP-3530 hardware platform specification to modify parameters and implement Embedded Android/DVSDK Multimedia System. Through Digital Signal Processor, the decoding process is enhanced effectively to provide user a high-quality multimedia service. Meanwhile by the increment of Multimedia service accessed by mobile devices, power management issue became important. Respond to that issue, this study enables Dynamic Voltage and Frequency Scaling power control mechanism in Android/DVSDK architecture. This mechanism enables CPU Frequency adjustment to reduce devices power consumption depends on system state. Through the proposed Android/DVSDK Platform, the multimedia services frame rate is increased from 24 Frame Per Second to 28 Frame Per Second and achieves the mitigation power consumption by 1.5%.

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