Abstract
With the growing development and popular exercise of wireless network, multimedia applications provided on mobile devices have increased gradually, including voice, music, image, video, and the interaction by the communication network. It is now an important issue to accomplish a system architecture with multi-processors to deal with different requests from multimedia applications. Today, heterogeneous dual-core architecture has been a popular research and implementation on mobile devices. It refers to a Main Processor Unit(MPU) cooperates with a Digital Signal Processor(DSP), which takes charge in complex numerical computation procedures, to meet the requests of communication and multimedia applications on mobile devices. When porting multimedia applications on different platforms, developers usually need to re-design and re-write those codes, which will be time-consuming. To solve this problem, the Khronos Group has defined a set of standards and Application Programming Interfaces (APIs), called OpenMAX(TM), to provide portability for multimedia applications. With two main interfaces: Integration Layer and Development Layer, OpenMAX(TM) APIs enables effective development of media codec implementations, regardless of underlying hardware architecture[4]. The main research of this thesis is to implement H.264 baseline profile decoder on a Dual-Core platform, combined with an ARM processor as the MPU, and a PACDSP developed in STC of ITRI. We adopt PACDSP Assembly language and follow the definition of OpenMAX(TM) DL to design a set of libraries for developers to easily invoke H.264 decoder functions. Then we discuss the influence of function allocation using OpenMAX(TM) definition, and analysis the efficiency of the H.264 decoder on both Single-Processor and our Dual-Core platform. Finally, we discuss the impact that the communication mechanism between MPU and DSP has brought to the system implementation.