How to use RTSP and multicast streaming?

[#1]

Multicast Options:

There are different ways for a client to receive a multicast stream:

• the client can connect to the camera and request a multicast stream. In this case you would see a connection in the dashboard.
  • If not checked, it requires at least one connected client to have the camera provide the stream into the multicast group. Clients who just joined would receive no stream if there is no client connected.
• the client can join an existing multicast stream without connecting to the camera. It must know the multicast group. You would not see this client on the dashboard.
  • The streaming flag tells the camera if it should feed its stream into this multicast group, regardless of a connected client. This is an option if there are many, many clients possibly connecting to the same camera/stream.

There is no difference in data amount if streaming is checked or not as long as there is at least one multicast client connected to this multicast group.

Below you find a way how to pass a special connection string to request a multicast stream via RTSP from a BOSCH IP camera or IP encoder.

Step-by-step guide

The following string triggers the connection to be multicast stream using the multicast IP and port that were predefined in the configuration before.

• rtsp://192.168.0.1/&multicast_video=1
• see device webpage --> Settings --> Network --> Multicasting
  
  

If you want to get the multicast stream on a specific IP and port (e.g. IP 226.1.2.3, port 1234) you can use following syntax:

• rtsp://192.168.0.1/&multicast_video=1&mc_group_video=226.1.2.3&mc_port_video=1234
  
  You can also use the RTSP SETUP command to enable multicast streaming.
  Note: Forwarding the RTSP port using RTSP SETUP command is supported with firmware 5.50 and later.

There is also a posibility to use SDP file:

• You should configure the encoder to create cyclic I-frames, do not leave it on auto but set e.g. to 30.
• Enter a multicast group address and set the streaming checkbox.
• Then record the connection setup with Wireshark and save the relevant info as SDP file locally. Then, the payload type should be correct.
• If necessary, edit the SDP file to match your intended multicast group address and port, and check the payload type which should be 35 for H.264.
  • There are two locations in the file for the payload type.
• Then open the file in VLC.

The SDP file should look like this:

v=0

o=- 0 0 IN IP4 <ipaddress>

s=LIVE VIEW

t=0 0

m=video 60010 RTP/AVP 35

c=IN IP4 226.1.1.1

a=rtpmap:35 H264/90000 

• Alternativly, there is an undocumented (thus untested and without guarantee that it is fully functional) feature in our devices that allows to download an SDP file:
  • http://<ipaddress>/live.sdp?line=1&h26x=4 via browser and save it locally.
  • Edit the file as nessesary and open in VLC.

PDF: Please see also the attached PDF from year 2016 which is still of help these days