V4L: UVC H.264 bit rate control
VLC is currently unable to select the bitrate of hardware-encoded H.264 stream coming from a webcam (at least not that from Logitech C920).
This is supposedly possible, albeit with an awful and under-documented interface. Low-level UVC controls are documented in kernel sources but that is a very small piece of the puzzle. If someone is interested, consider borrowing code from gst-plugins-bad uvch264 source.