Implementation of H.264 on Mobile Device
This paper introduces the performance and technical features of the new generation international video coding standard H.264, as well as discusses the implementation and optimization of H.264 on mobile device. Our work is to implement H.264 Baseline Projile encoder and decoder on an HP IPAQ hx4700 PDA (Personal Digital Assistant) which has a powerful embedded processor PXA27x produced by Intel. By using the way of system optimization, algorithm optimization and instruction optimization, we have successfully implemented the H.264 codec on mobile device and made great improvement in terms of coding speed with very little performance degradation in terms of PSNR and bit-rate. Experimental results show that the speed of our codec increases significantly after optimization (much more than 25 frames per second). In the QCIF (176times144) resolution, our codec can run in real time on the mobile device. Based on our optimized real-time H.264 codec, a wireless video conferencing system is implemented and is described in this paper.