Abstract: In the design and development of USB camera drive based on embedded system, it should make full use of USB bus bandwidth and ensure a high and stable data transfer speed between memory and peripherals. In order to meet the real-time video capturing requirements, reference is made to open-source projects GSPCA/SPCA5xx, recommendation of Linux kernel is adopted, and using double-URB strategy and MMAP mapping mechanism to maximize the video capturing speed, eventually realizes this USB camera drive in line with Video4Linux on the S3C2440AL_ARM development platform and provides a functional verification and performance analysis.

Key words: embedded Linux, USB camera, double-URB strategy, MMAP mapping mechanism

摘要： 在嵌入式系统中开发USB摄像头驱动需要充分利用USB总线带宽并保证内存与摄像头之间数据的高速稳定交换。为满足该要求，参考开源项目GSPCA/SPCA5xx，采纳Linux内核建议并遵循Video4Linux标准，提出双URB分配策略和MMAP内存映射机制以最大限度地提高视频采集速度。在S3C2440AL_ARM开发平台上设计并实现USB摄像头的嵌入式Linux设备驱动，对该驱动程序进行功能验证和性能分析。

关键词: 嵌入式Linux, USB摄像头, 双URB策略, MMAP映射机制

CLC Number: 

• TP301.6