Smartest and cleanest way to see if there's a process capturing v4l2loopback a device

Question

I have a gstreamer pipeline where I am pushing data to a v4l2loopback device and then picking it up from browser.

From gstreamer's C code what is the smartest way to see if browser is actively capturing from the device or not ?

I have used popen making a fuser call, but was hoping on something cleaner :)