[GithubPages] 本篇文章写一下 V4L2 里面的众多 control 的组织方式,也就是它的数据结构。主要就是新建的 control 是如何存放的,以及在需要用到的时候如何查找。里面用到了类似于「桶」的概念,没错就是「桶排序」里面的那个桶,这种比较特殊的小优化为查找速度提供了不少的帮助。 话不多说,直接进入正题,本文章...
v4l2_subdev_core_ops中所有的核心控制行动如下: .queryctrl = v4l2_subdev_queryctrl, .querymenu = v4l2_subdev_querymenu, .g_ctrl = v4l2_subdev_g_ctrl, .s_ctrl = v4l2_subdev_s_ctrl, .g_ext_ctrls = v4l2_subdev_g_ext_ctrls, .try_ext_ctrls = v4l2_subdev_try_ext_ctrls, .s_ext_ctr...
V4L2 can not handle implemented controls, example: root@user:~# v4l2-ctl --verbose -L VIDIOC_QUERYCAP: ok root@user:~# v4l2-ctl --set-ctrl brightness=192 unknown control 'brightness' It is a bit known issue, but hope someone will help me to find solution faster.How to fi...
The v4l2-ctl tool is used to control video4linux devices, either video, vbi, radio or swradio, both input and output.
v4l2-ctl[-h] [-d<dev>] [many other options] DESCRIPTION The v4l2-ctl tool is used to control video4linux devices, either video, vbi, radio or swradio, both input and output. It is able to control almost any aspect of such devices convering the full V4L2 API. ...
unable to open control device '/dev/v4l2loopback': No such device Steps to replicate: Build and install non-dkms v4l2loopback with its utilities on Ubuntu 20.10 $ sudo v4l2loopback-ctl add -n "Webcam 1" /dev/video1 It succeeds at first After some time and doing ??? (maybe rebo...
RTSP video stream shown in the video window with DeepStream 6.2 installed. Current Behavior RTSP video stream is not working when DeepStream 6.2 is installed. It adds new decoder type callednvv4l2decoder, which is not handled by QGroundControl and fails to be linked to the sink element. It ...
V4L2 can not handle implemented controls, example: root@user:~# v4l2-ctl --verbose -L VIDIOC_QUERYCAP: ok root@user:~# v4l2-ctl --set-ctrl brightness=192 unknown control 'brightness' It is a bit known issue, but hope someone will help me to find solution faster.How to f...
v4l-utils_1.22.1-5build1_amd64 NAME v4l2-ctl - An application to control video4linux drivers SYNOPSIS v4l2-ctl[-h] [-d<dev>] [many other options] DESCRIPTION The v4l2-ctl tool is used to control video4linux devices, either video, vbi, radio or swradio, both input and output. It ...