Looks as You need to know the default user and password fot that device.
You can try in the user manual, contacting SAT or googling.
Ah, “Onvif Manager” software (I have it for windows) can detect compatible onvif cameras and the stream url !
The URL would be as rtsp://user:pass@camera_ip:554/rtsp_live0
I hope this help to help you 
I have just advertise that You wrote:“camera_ip:8554/rtsp_live0”
:8554 ? Is correct or a mistake?