ONVIF PTZ状态响应

Question

I'm using the web services provided by ONVIF to communicate with surveillance camera, so far so good. My next objective is to create a FOV, and for that I need a continuous status update from camera.

The ideal situation for me is to receive the absolute PTZ position after each camera movement, but so far didn't find a way to do so. There is the option of sending GetStatus() method which gives me the info, but sending it after each call is expensive and clumsy.

Am I missing anything? WireShark tells me that the response for ContinuousMove for example is ContinuousMoveResponse. Without any status for PTZ position.

Any help or advice would be appreciated.

Thanks

Answer 1

You are correct that you can retrieve the camera's coordinates with GetStatus() and as you can see here , ContinuousMoveResponse is empty. This is because if you don't specify any timeout then the unit keeps the specified speeds for ever. If you specify a timeout, ContinuousMove() may return earlier than the device actually finishes moving.

I don't really get why you complain that GetStatus() is expensive and clumsy. Anyway, this is the only way to know in ONVIF the orientation for every possible ONVIF-certified camera.

Some cameras may (but they are not mandated to) send the PTZ coordinates in the RTSP stream as ONVIF metadata.