Usb-based Interface Multi-channel Video Capture Technology Research

In the machine vision measurement system, video data collection and transmission system is a necessary component. The video acquisition system based on USB interface has advantages of low cost and convenient use, thus can meet most of the testing systems. But to the machine visual test system that has multiple video inputs, there is no single USB interface can complete data acquisition system. According to a research task, the goal of this paper is to develop a single interface based on USB, capable of multi-channel video acquisition and transmission system.Fristly, this article introduces something about the video which is mainly related to ITU-R BT.601 protocol, then, it describes how the decoder chip works in this design. This article also detialedly analyzes some important concept about USB2.0 protoctl, such as USB architecture, USB descriptors, USB packet formats, USB transfer mode, etc. Then, the article discusses the characteristics of CY7C68013 (an USB2.0 interface), the characteristics are mainly about the Slave FIFOs, it also describes the core framework of the firmware. As 68013 use its Slave FIFOs, an external data-processing logic is needed, so, author design the appropriate state machine. After this, the experience of hardware design and debugging process was shared in this article. Finally, something about the software design was ayalyzed. Software design includes the driver design and application design. For driver design, WMD driver model was used; for application design, author used MFC for multithreaded programming.The works that has been done for the USB-based multi-channel video capture system are mainly hardware and software design. Hardware design includes schematic design, PCB design, hardware debug, firmware design and state machine design. Software design includes driver design and application design.