基于ARM926EJ-S的MPEG-4软解码器的优化与实现

MPEG-4解码器的软件实现是嵌入式应用领域的热门研究课题。但是由于MPEG-4解码系统庞大的数据处理量和嵌入式微处理器处理能力不高的矛盾致使软解码的速度非常低。对此,根据MPEG-4软解码系统的特性及当前嵌入式领域主流微处理器ARM核的特点,研究了一种基于ARM9微处理器上实现MPEG-4软解码的算法优化方法和实现方案。详细介绍了优化的三个方面,包括软件结构优化;对数据处理较多模块编写ARM汇编函数替换;对关键模块寻找快速算法和并行处理算法等。实验结果表明优化后的算法在ARM9微处理器平台上对QVGA格式的MPEG-4码流播放速度由优化前的10 f/s提高到了37 f/s,完全实现了流畅播放,具备很高的实用价值。

Optimization and Realization of MPEG-4 Soft Decoder Based on ARM926EJ-S

nowadays,the software realization of MPEG-4 decoder is the hotspot of the embedded application research.However the speed of soft-decoder is very low because of MPEG-4 decode systematic huge data treating and embedded micro-processor limited process capability.For this,according to the property of MPEG-4 soft decode system and characteristic of the ARM micro-processor nucleus,introduces a kind of algorithm optimization method that realizes MPEG-4 soft decode on ARM9 micro-processor.Mainly involves optimizing software architecture,programming ARM assembly function for modules which handle much data,seeking the fast and parallel algorithms for the key module.Through the optimization,the decoding speed increases from 10f/s to 37f/s when the decoder running on the ARM9 with QVGA format,which has met the real-time decoding requirements.