[libcamera-devel] Accessing all available framesizes to display in qcam

[Your Name]

Hello,
 I am trying to access all the frame sizes that are available in order
 to list it out in qcam as a drop down menu. When I try to add the
 following code in v4l2_device.cpp inside int V4L2Device:open()  
 
	struct v4l2_frmsizeenum v4l2frmsizeenum = {};
	ret = ioctl(fd_,VIDIOC_ENUM_FRAMESIZES,&v4l2frmsizeenum);
 The ret value comes out to be -1 indicating an error with ioctl.

 The standard 
	ret = ioctl(fd_, VIDIOC_QUERYCAP, &caps_);
 seems to work just fine. 

 Is there something specific in v4l2 that I am missing to query all the
 frame sizes? It would be better if it's located somewhere else in the
 libcamera repo.

 I am learning how to help with open source development. I can reformat
 the message if you think it is more appropriate. 

 I am using Logitech HD Pro Webcam C920 on ubuntu 18.04.

 Thanks,
 H