Dahua cameras should work with the following URL (set to Other IP Camera > RTSP):
rtsp://<ipaddress>:554/cam/realmonitor?channel=1&subtype=0
or
rtsp://username:password@<ipaddress>:554/cam/realmonitor?channel=1&subtype=0
Cameras have only one channel, but other devices (NVRs) have multiple channels. The subtype defines the stream: 0=main stream (high quality), 1=sub stream (lower quality).
I hope Sighthound could make a camera definition "Dahua Generic" as there are tons of them out there right now, plus many more rebranded models. It would be great to select the channel and stream from the interface and not mess around with the URL.