Implementation And Optimization Of WMA Decoder On ARM Cortex-A8 Platform

With the development of multimedia technology, more and more multimedia applications have been used in different occasion, thus many multimedia processing technologies have been adopted in all kinds of SOC systems, including ARM core, MIPS core and other platforms. ARM Cortex-A8 is the latest processor developed by ARM Company which using ARMv7 instruction set architecture, contains 13 stages integer pipeline along with 10 stages pipeline in its NEON co-processor, a powerful multimedia engine.WMA (Windows Media Audio) is an audio format developed by Microsoft. `It is one of the most popular music file format used in the internet and storage systems.In this paper, we focus on the WMA10 decoder's optimization at ARM Cortex-A8 platform. Firstly we briefly introduce WMA and some digital audio standards and analyze the target ARM platform, especially for its instruction set architecture, pipeline and its unique NEON multimedia engine (with Parallel processing mechanism), then we introduce modules of WMA decoder. On the basis of which, we apply some optimized algorithms specializing for Cortex-A8 platform. Finally, the performance result of optimized and original code is given. For the worst case, we can get the performance improvement of more than 70% compared with the original C code.