| The digital multimedia technology has been developing rapidly,and the digital video industry is rapidly moving towards the era of 4K ultra high definition.With the increasing number of hardware devices that support 4K ultra high definition resolution,many kinds of signal interfaces that support 4K signal transmission are also came into being.As the standard interface of 4K TV and multimedia device,HDMI signal interface has been widely applied to various consumer electronics,SDI signal interface is widely used in professional broadcast video production equipment.Due to different interfaces are supported by different transmission standards,different signal sources can not be directly transmitted to devices with different interfaces.The diversity of interfaces makes it difficult for a single display device to have all the interfaces to be compatible with different signal sources.The interface signal conversion in the ultra high definition video field has become a problem that needs to be solved.Therefore,HDMI to 12G-SDI format conversion technology supporting 4K resolution will have important research and design significance and wider market application value.Based on the HDMI decoder chip and FPGA,this signal conversion technology combined with pixel data splicing,image division,data stream mapping,audio data encapsulation,data embedding and data stream multiplexing technology,to designed and implemented the signal format conversion system,which can meet the needs of HDMI signal input by professional4K video production equipment with SDI interface.,this paper mainly includes four modules:4K HDMI signal receiving and decoding module,12G-SDI video signal coding module,12G-SDI audio signal embedding module and 12G-SDI serial output module.In this paper,the nmain contents are as follows:(1)On the basis of HDMI2.0protocol standard and 12G-SDI related SMPTE standard,the implementation is studied in depth,including HDMI decoding,12G-SDI signal coding and 12G-SDI audio embedding.(2)From the perspective of the application of signal format conversion system,the function and performance requirements of signal format conversion are analyzed in detail.Considering the complexity and hardware cost of various design schemes,we have draw up the design plan of this project and selected the related chips,and use the layer architecture to design system overall scheme and module division.(3)Each module of the system is specifically designed and implemented.(4)Test the function and perfonnance of the designed signal format conversion system.The actual test results show that the designed signal format conversion system can convert the HDMI video source of 4K resolution to 12G-SDI video signal output correctly and the physical layer characteristics of 12G-SDI conform to the SMPTE standard.The 4K image after the conversion is clear and smooth,and the audio and video can be synchronized,which achieve the desired design goals.In this paper,the 4K HDMI to 12G-SDI signal format conversion system based on FPGA has the characteristics of clear module function division,low conversion delay,high conversion stability and low hardware design cost.The research results of this subject have practical application value for the HDMI to SDI signal format converter in the field of 4K,and also have some reference for the design of othe type of signal format converter. |
