| With the our government promotion for telecommunications network, Broadcast television network and internet three network fusions and the development of WLAN, LTE and other wireless mobile communication technology, using ultra-high-speed mobile communication systems transmit high-definition real-time broadcast television signals not only be allowed from the policy, but also provides a technical basis. The system of mobile HD codec will greatly reduce the use of live television costs and increased flexibility.The system of mobile HD codec is an embedded system terminal that based on embedded Linux operating system, therefore, in this thesis, the embedded system has been exhaustive analyzed. The system supports Ethernet, WLAN and TD-LTE three kinds of transmission mode. WLAN and TD-LTE mode can meet the demand for mobility.Because of high-definition television signal (HDTV) enormous amount of data and the transmission network bandwidth is limited, the HDTV signals must be compressed and encoded by H.264 standard, and then transmission. H.264 is a digital video compression coding standard of ITU development, with very high compression ratio and better performance of wireless channel. In this thesis, the H.264 standard has been exhaustive analyzed, and in this system, the H.264 standard has been implemented by MB86H56 chip.In this paper, the SIP protocol has been exhaustive analyzed, SIP protocol is a signaling protocol of IETF establishment, and it can complete building, modification and release function of multimedia session. SIP protocol has been implemented by the oSIP and eXosip open source protocol stack. Therefore, in this article, it has been exhaustive analyzed that the structure, development and design of the oSIP and eXosip open source protocol stack.In this paper, we propose RTP protocol to improve real-time voice service transmission performance over IP network, and RTP protocol has been exhaustive analyzed. RTP protocol has been implemented by the oRTP open source protocol stack. Therefore, in this article, it has been exhaustive analyzed that the structure, development and design of the oRTP open source protocol stack, and multimedia management is implemented through the technology of multi-thread.Finally, the system of mobile high definition codec has been tested, by analyzing, SIP signaling interaction is normal, the HDTV signal can be transmitted through Ethernet, WLAN and TD-LTE network, and the quality of signal transmission is fine. |
PDF Full Text Request