Why the ONVIF driver does not send PTZ Stop command?

There are two ways in ONVIF to stop Continuous PTZ movement:

• Using Stop command

• Using ContinuousMove command with velocity set to zero.

The ONVIF driver uses the second option. This is perfectly OK as specified in the PTZ Service specification:

Section 5.3.3 ContinuousMove

“A device shall stop movement in a particular axis (Pan, Tilt, or Zoom) when zero is sent as the ContinuousMove parameter for that axis. Stopping shall have the same effect independent of the velocity space referenced. This command has the same effect on a continuous move as the stop command specified in section 5.3.5.”