在嵌入式數位訊號處理器核心的系統平台上，為了讓應用程式能夠及時執行在數位訊號處理器核心上，必須要將軟體做最佳化處理。本論文採用的應用程式為H.264/AVC，是ITU-T提出的一種新的影像編碼標準，主要是利用一些新加入的特徵以及功能，可以達到高壓縮率的效果。但是因為如此，所以會增加一些運算的時間以及運算複雜度。正因如此，本系統平台無法及時播放H.264的原始程式碼，所以必須用軟體分析的方法將原始程式最佳化，加快程式執行速度與減少程式大小，以符合本系統平台所能提供的系統效能與記憶體資源，進而將程式載入平台上執行。
我們先用Visual C++此整合開發環境將H.264原始程式做統計數據分析，找出函式執行次數最多次與執行時間最長的一些函式，配以系統提供之內建函式庫，與刪除不必要的函式與變數，針對其執行次數最多與執行時間最長的程式將之做軟體最佳化處理，以減少數位訊號處理器的運算量。另外，為配合此H.264應用程式能夠在此嵌入式數位訊號處理器開發平台上正確執行，伺服器必須在軟體開發環境與硬體開發環境上交互模擬，如此才能確認軟體開發環境產生的二位元碼能夠在此數位訊號處理器核心上正確執行。最佳化之後，我們可以估計達到即時播放所需的DSP時脈，和真實的DSP硬體時脈做比較，朝能及時播放的目標邁進。

In order to execute the application programs in the embedded Digital Signal Processor (DSP) core system platform in real-time, we need to do the software optimization. In the thesis, we adopt H.264/AVC source code as our application program. H.264/AVC is a new video coding standard proposed by ITU-T, which can achieve high compression efficiency by adding new characteristic coding functions. Therefore, the H.264/AVC program will increase computation time and computation complexity. Due to the fact, the system platform can’t display H.264/AVC video in real-time. We need to optimize the source code by software analysis and optimization methods to increase the program speed and code size to meet the system platform performance and memory resource.
First we use Visual C++ to profile the H.264/AVC open source code to make the statistics about the hit counts of functions and the longest execution time by a function. We integrate the intrinsic libraries and remove unnecessary functions and variables and perform software optimization methods to optimize the H.264 source code. In additional, we have to co-simulate the software development environment and hardware develop environment to make sure that the DSP core can run the H.264 binary code generated by the software toolchain correctly. After optimizing the H.264 source code, we can estimate the required real-time DSP clock rate simulated by software and compare the actual DSP core to achieve the real-time objective.

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