Design And Implementation Of DVR In Fighter

VTR is a device installed in the fighter aircraft cabin, which is employed to record the display picture and the conversation sound in flight for ground analysis. VTR adopts the analog recording method, taking the magnetic tape as the recording medium. In view of the fact that the aseismatic design of the domestic magnetic head mechanism has been lagged behind, this equipment has long been relying on importation. With the vigorous development of the electronics and computer technology, the digital video compression technology has been made progress unceasingly, which has already been universally applied in domains such as defense and traffic control. Its general document management way and clearer video effect is recognized by the avionic electronics system. DVR has already been used abroad as the aircraft-borne recording equipment, therefore,it has become an urgent need for DVR to replace VTR as a new member in the avionic electronics system to promote the domestic plane battle effectiveness.The article designs a DVR in light of actual demand of some fighter, which can record one channel standard video, three channel XGA video and one channel audio for three hours.This article mainly includes two parts: the system analysis and design and the system realization. This article carries on the system analysis and the design chapter from four aspects: the video compression plan, the video compression algorithm, the video gathering and the data storage, and particularly introduces many design processes such as the system structure, the system application and video playback and so on in the system realization chapter. Various parts of primary coverage are as follows:1) For the video compression plan, the article enumerates two prevalent realization plans at present, and carries on analysis and contrast between ASIC and the DSP plans. Although both have advantages and disadvantages, the article finally chooses DSP plan for its high flexibility and extendibility, and further introduces the relating technical information in detail.2) Until now, there are many algorithms and standards for image and video compression. This article introduces JPEG, MPEGx and H.26x. through contrasting their technical characteristics and the serviceability. H.264, the newest and also the most promising compression standard, is chosen and optimized contraposing the aircraft-borne video characteristic in practical application, in particular the XGA high resolution video compression first in use in the domestic aviation domain.3) For the video gathering aspect, this article discusses the standard video and the XGA video gathering plan respectively, introduces the correlative realization technology in detail. XGA video gathering was applied for the first time in domestic, previously limited by lack of decoder chip. At first, the XGA video can only be transformed to standard video before gathering. Until the high resolution decoder chip came out later, XGA video gathering has adopted the direct processing mode.4) On the data storage aspect, based on using features and from the practical application, this article suggests that data storage equipment should employ the inserting and pulling design in the card structure. The article also analyzes and computes the video bit stream in combination with the optional scope at that time, so as to determine the storage capacity and interface, finally chose 16GB flash disk as memory part.5) Regarding the system structural design, this article carries out a comprehensive argumentation from the CPU selection, the bus, the data transmission and storage as well as the operating system, the file system and so on, then proposes a concrete system structure realization plan, and divides the function module for elaboration of the plan.6) In light of the actual using situation in fighter, this article explains the concrete design process of the system application, especially the synchronized design, file management and algorithm optimization.7) Video playback is the most direct-viewing way to examine DVR's function and performance, also it is a extended function of DVR. This article combines the characteristics of multi-channel sound and video synchronization playback, uses the dual processor workstation as hardware platform, together with multi-channel video play software to realize the playback.The significance of the article lies in the point that it not only succeeds in designing the first native aircraft-borne video recording equipment, but also becomes the first domestic XGA video compress recorder system with high resolution. The entire design flow, especially the XGA high resolution video gathering and compression plan and the system structure designing, demonstrates general reference value and guidance to correlation application.