On 10/07/2020 16:18, Lucas wrote: > Hello, how do I obtain the accepted range of values for each V4L2_CID > command? Take V4L2_CID_BRIGHTNESS as an example, how do I know what is > the maximum and minimum values accepted for it? I have tried to use > 'v4l2_ioctl(fd, VIDIOC_G_CTRL, &query);' thinking that would be stored > in the maximum and minimum members for the struct v4l2_queryctrl but > that does not appear to be the case as the values for those members are > always zero. Use VIDIOC_QUERYCTRL for that. See: https://linuxtv.org/downloads/v4l-dvb-apis-new/userspace-api/v4l/vidioc-queryctrl.html Regards, Hans
