Camera Operation
In general the streamer in Arecont cameras works by splitting the total encoder FPS by the number of concurrent streams consumed by clients. If the encoder in the camera is able to provide 12 FPS then this number will be divided by the number of clients, e.g 2 clients connected to a camera set to 12 FPS will each receive 6 FPS. As the number of clients increases the FPS will continue to split, e.g. 4 clients would each receive 3 FPS and so on. Per Arecont their cameras support a maximum of 8 concurrent streams. In a ViconNet system this becomes a burden on the camera since in ViconNet; Workstations, NVRs, VMDCs, and DVRs would each make an independent connection to the camera. This means that 1 NVR and 1 Workstation would each receive only 6 FPS from a camera capable of delivering up to 12 FPS. Arecont cameras do not provide a way via the web GUI to adjust FPS or GOP as it is done dynamically by the camera. The encoder's capability varies by model so it is recommended to first verify the FPS capability of the camera.
Operation in ViconNet
The ArecontVision driver in ViconNet streams via HTTP by default. The VnUtils configuration tool can be used to change the communication method to multicast which will then switch the streaming to RTSP. Versions of ViconNet prior to 8.1 did not support streaming via multicast for the ArecontVision driver. The change can also be done manually via the ThirdParty.ini file the entry must be as follows:
[Arecont]UseHttp=0
UseMulticast=1
In systems where it is required to record/view a high FPS stream from the camera it would be recommended to configure the network for multicast traffic and then configure all ViconNet systems to stream via multicast for all Arecont cameras.
Operation in Valerus
In an Valerus system the burden on the camera should be minimal as in Valerus the NVR will pull one stream from the camera and then handle the streaming to all clients. The only scenario in which the FPS limitation can become a problem is if the NVR goes offline causing all of the clients to pull streams directly from the cameras. In Valerus it is recommended to use ONVIF but GenericRTSP can also be used. Onvif operation of ArecontVision cameras is completely dependent on the model and firmware version in the camera. For further info please check with ArecontVision to determine what each camera supports.
Custom RTSP streaming operation
ArecontVision cameras have the capability of providing different streams depending on the stream URI. Parameters can be passed to the camera's encoder via the RTSP URI. For further info please review the ArecontVision documents in regards to the specific camera model in use.
General RTSP URI format:
RTSP://IpAddr/video(C).sdp?res=(R)&x0=(X)&y0=(Y)&x1=(X2)&y1=(Y2)&qp=(Q) where the variables equal the following:
C = channel number (e.g. 1,2,3, or 4)
R = resolution (e.g. full, or half)
X, Y = Width & Height origins (e.g. 50px)
X2, Y2 = Final Width & Height (e.g. 1920px)
Q = stream quality (e.g. 16)
Below is an URI sample for model AV12176DN.
RTSP://IPaddress/video1.sdp?res=full&x0=0&y0=0&x1=2048&y1=1536&qp=16&5000&snapstream=off&ssn=205&doublescan=1&bitrate=3000&fps0&mic=off
RTSP://IPaddress/video2.sdp?res=full&x0=0&y0=0&x1=2048&y1=1536&qp=16&5000&snapstream=off&ssn=205&doublescan=1&bitrate=3000&fps0&mic=off
The ArecontVision API docs cover this info, please refer to Arecont's docs for a complete guide.
Page 126 of the manual in the link below contains the RTSP API information.
API document (may be outdated)