Chapter 8
Video for Linux Two (V4L2) Driver
8.1 Introduction
The Video for Linux Two (V4L2) drivers are plug-ins to the V4L2 framework that enable
support for camera and preprocessing functions, as well as video and post-processing
functions.
The V4L2 camera driver implements support for all camera related functions. The V4l2
capture device takes incoming video images, either from a camera or a stream, and
manipulates them. The output device takes video and manipulates it, and then sends it to
a display or similar device.
The features supported by the V4L2 driver are as follows:
• Direct preview and output to SDC foreground overlay plane (with synchronized to
LCD refresh)
• Direct preview to graphics frame buffer (without synchronized to LCD refresh)
• Color keying or alpha blending of frame buffer and overlay planes
• Streaming (queued) capture from IPU encoding channel
• Direct (raw Bayer) still capture (sensor dependent)
• Programmable pixel format, size, frame rate for preview and capture
• Programmable rotation and flipping using custom API
• RGB 16-bit, 24-bit, and 32-bit preview formats
• Raw Bayer (still only, sensor dependent), RGB 16, 24, and 32-bit, YUV 4:2:0 and
4:2:2 planar, YUV 4:2:2 interleaved, and JPEG formats for capture
• Control of sensor properties including exposure, white-balance, brightness, and
contrast
• Plug-in of different sensor drivers
• Link post-processing resize and CSC, rotation, and display IPU channels
• Streaming (queued) input buffer
• Double buffering of overlay and intermediate (rotation) buffers
• Configurable 3+ buffering of input buffers
• Programmable input and output pixel format and size
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc.
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