tmp_摄像头控制接口#

V4L2应用程序开发#

参考资料：

  • mjpg-streamer：https://github.com/jacksonliam/mjpg-streamer

  • video2lcd：这是百问网编写的APP，它可以在LCD上直接显示摄像头的图像

  • 这2个源码都放在GIT仓库里： image-20230617173258521

1.#

To be able to manipulate the physical properties of a video function, its functionality must be divided into addressable entities. The following two generic entities are identified:

  • Units：Selector Unit 、Processing Unit 、Encoding Unit 、Extension Unit

  • Terminals ：Input Terminal (IT) 、Output Terminal (OT) 、Camera Terminal (CT)

  • A Camera Terminal is always represented as an Input Terminal with a single output pin. It provides support for the following features

    • Scanning Mode (Progressive or Interlaced)

    • Auto-Exposure Mode

    • Auto-Exposure Priority

    • Exposure Time

    • Focus

    • Auto-Focus

    • Simple Focus

    • Iris

    • Zoom

    • Pan

    • Roll

    • Tilt

    • Digital Windowing

    • Region of Interest

Controls have attributes, which might include:

  • Current setting

  • Minimum setting

  • Maximum setting

  • Resolution

  • Size

  • Default

Processing Unit

  • User Controls

    • Brightness

    • Hue

    • Saturation

    • Sharpness

    • Gamma

    • Digital Multiplier (Zoom)

  • Auto Controls

    • White Balance Temperature

    • White Balance Component

    • Backlight Compensation

    • Contrast

  • Other

    • Gain

    • Power Line Frequency

    • Analog Video Standard

    • Analog Video Lock Status

Extension Unit

对于每一个entity(IT,PU,SU,OT等)

  • IT: input terminal

  • OT：output terminal

  • VC: video control

video function：含有几个interface，每个video function含有一个VC(video control)、多个VS(video streaming)，它们被称为VIC。

参考资料：

https://www.php1.cn/detail/CSS_YangShiGuiZe_218a96fe.html