| With the rapid development of the network and communication technologiesand the increasingly maturity of the multimedia and audio/video codec technologies, a large number of multimedia communication services emerge in Internet. VoIP enable PC to communicate with phone with voice and video on the Internet, and may also exchange text content and image files, which can be further expanded in the actual application scene such as telemedicine, distance education. As the maturing of VoIP market and technology and the popularity of mobile Internet, simply running telemedicine applications on a PC will not meet users’ needs in terms of mobility and portability, so it is necessary tolaunch the research to embedded mobile devices.Based on Freescale i.MX6 multimedia processor, in order to solve the high CPU usage and the discontinuous sound and the less smooth video problems caused by it. Through studing and analyzing the embedded remote medical assist system and the open source projects Linphone which is a SIP VoIP, we design the system solution that taking advantage of the hardware codec features of i.MX6’s VPU software, and integrating it into the Linphone. Then apply it to the telemedicine assist system.Finally, after lots of rigorous testing, H.264 codec performs well at remote dedical assistance system, user experience and performance improvements in audio and video have achieve the demand and the expected results. When the resolution is set CIF 352*288 and limit bandwidth is between 350-380Kbit/s at LAN environment, the CPU usage is controlled at 30% or less, the delay is less than Is, audio and video calls perform smoothly. It also shows the feasible of our solution of using hardware features of i.MX6 of VPU to optimize codec, and it also has a certain reference value for other similar systems. |
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