DevKit8500D/A User Manual - DMCS Pages for Students

3.5.4 Video capture
Video capture application
Use
r
V4L2 LAYER
CAMERA DRIVER
Kernel
CCDC DRIVER
DECODER DRIVER
HARDWARE
Hardware
Figure 3.5.4 Modular structure for video capture
V4L2 Subsystem:
The Linux V4L2 subsystem is used as an infrastructure to support the operation of the Camera
Driver. Camera applications mainly use the V4L2 API to access the Camera Driver functionality. A
Linux 2.6 V4L2 implementation is used in order to support the standard features that are defined in
the V4L2 specification.
Video Buffer Library:
This library comes with V4L2. It provides helper functions to cleanly manage the video buffers
through a video buffer queue object.
Camera Driver:
The Camera Driver allows capturing video through an external decoder. The camera driver is
registered to the V4L2 layer as a master device driver. Any slave decoder driver added to the
V4L2 layer will be attached to this driver through the new V4L2 master-slave interface layer. The
current implementation supports only one slave device.
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