近幾年手持行動裝置的功能越來越多元化，許多人使用手持行動裝置來播放音樂，影片或是儲存圖片，行動多媒體顯然已是消費者在選購手持裝置時的重要考量之一。然而，多數嵌入式系統仍為單核心處理器架構，且由於省電的考量，其時脈也受到嚴格的限制。異質多核心架構提供較佳的效能表現但又可保持低功耗，目前成為嵌入式系統最主流的架構。
但現階段的Android是以單核心架構設計，此作業系統完全都以MPU（main processor unit）執行所有程序，而嵌入式系統中MPU的運算效能及系統搭載的記憶體效能不彰，在處理複雜的影音解碼運算時，多媒體框架無法負荷龐大的資料運算，導致影音解碼無法流暢的播放。因此如何善用異質多核心架構提升多媒體資料的運算已成為嵌入式系統上重要的議題之一。
本論文採用的平台是工研院晶片中心開發的異質多核心平台－PAC Duo Platform，組成為一個ARM926EJ-S作為MPU，加上兩個PACDSP。PACDSP是一個高效能、低耗電率的數位訊號處理器，可將需大量運算的多媒體應用工作交由PACDSP處理。本論文並將PACDSP平行化之H.264解碼器整合至Android多媒體框架，其中包含Android 2.1版以前預設使用的多媒體框架－OpenCORE以及Android 2.2版以後預設的多媒體框架－Stagefright。並將此結果移植於工研院自主開發之PAC Duo平台驗證其正確性及效能表現，由於MPU的運算負載降低，實驗結果顯示H.264解碼效能於OpenCORE可增進53%~81%，在Stagefright效能可增進31%~83%，經由適當的工作分配，異質多核心平台可提升多媒體播放的效能且保持負載平衡。

In recently, the function of handheld mobile devices become increasingly diverse, many people use handheld devices to play music, video, or picture, clearly the multimedia function is one of the important considerations in purchase handheld devices. However, most embedded systems are still single-core processor architecture, and because of the power considerations, clock rete has also been strictly restricted. Heterogeneous multi-core architecture provides high computation power and also maintains low energy cost. It has become the mainstream embedded systems architecture nowadays.
But Android is based on single-core architecture at present stage, the operating system use MPU （main processor unit） to execute all procedures. And the MPU and memory in embedded system device are mostly not effective. When dealing with complex audio and video decoding operations, the multimedia framework can not handle with large data operations. The decoding of video and audio is not smooth. Therefore, how to make improve the utilization of heterogeneous multi-core architecture to enhance multimedia computing has become an important issue on embedded systems.
In this paper, we use the platform which is developed by the ITRI. It is a heterogeneous multi-core platform named PAC Duo Platform, composed of an ARM926EJ-S as the MPU, with two PACDSP. PACDSP is a digital signal processor with high performance, low power consumption. It is sufficient to deal with a large number of operations required by multimedia applications work. This paper integrated PACDSP parallel H.264 decoder into Android multimedia framework, including the default multimedia framework- OpenCORE of Android 2.1 versions and the default multimedia framework-Stagefright of Android 2.2.

We verify it correctness and performance with Android on PAC Duo Platform. Because the MPU computing load is reduce, experimental results show that H.264 decoding performance can be improve. Our experiment results enable PACDSP decoder-based multimedia framework processes of up to about 53% to 81% faster compared to the original OpenCORE. And 31% to 83% faster compared to original Stagefright. It means through the appropriate distribution of work, decode performance can be enhanced and can maintain the load balancing.

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