Video Capture System Based on PXA270 Platform

2. Pxa270 Platform Introduction

The PXA270 processor is the first Intel XScale technology-based processor to include Intel Wireless MMX technology. This enables high-performance multimedia acceleration with an industry proven instruction set. Enabled by Intel Quick Capture technology, the PXA270 provides one of the industry’s most flexible and powerful camera interfaces for capturing digital images and video (Lin, Liu, Xiong, Wang, & Zhang, 2007).

A set of serial devices and general-system resources offers computational and connectivity capability for a variety of applications. Figure 1 shows the development platform of PXA270 processor.

Figure 1.

Development platform of PXA270 processor

The paper introduces a video data capture system based on PXA270 platform.

3. Video Capture System

In Linux, device driver to the application details of shielding concrete implementation of hardware, so the application can operate like a normal file to operate as an external device. In Linux, the normal use of video capture device relies on the support of Video4Linux standards (Liao, Zhang, Peng, & Li, 2010).

Video4Linux (referred to as the V4L) is a Linux kernel on the video device driver that is for video equipment to provide a series of application programming interface functions, these video devices including TV cards, video capture card and USB cameras. The general process of video capture is:

• (1)

  Open the video device;

• (2)

  Read the device information;

• (3)

  Video capture;

• (4)

  On the acquisition of video data processing and display;

• (5)

  Off the video equipment.

Video capture comes from two methods:

• (1)

  Read directly from the device;

• (2)

  Memory map.

The system uses the second method for video acquisition, and the advantage is when using memory mapping, the direct use of mmap () system call allows processes by mapping a regular file with the shared memory.