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Video Streaming API
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the prior written consent of Axis Communications AB.
4 Always Multicast
Always multicast means starting a multicast stream and letting it run continuously. Enabling always multicast reduces the latency
when connecting to an Axis product. The always multicast streams enabled on the Axis product are presented by a Session Description
Protocol (SDP). Using this information the client can choose to connect to the service.
4.1 Prerequisites
4.1.1 Identication
Property: Properties.API.HTTP.Version=3
Firmware: 5.40 and later.
4.2 SDP
The client makes a request according to the example below. The camera parameter species the desired video source on the
Axis product.
To make a SDP request it is required that Network.RTP.R0.AlwaysMulticastVideo=yes.
4.2.1 Request SDP URL
Request:
http://myserver/axis-cgi/alwaysmulti.sdp?camera=1
4.2.2 Response SDP URL
The Axis product responds the request with a SDP. The SDP is protected by the HTTP authentication of the Axis product and requires
admin access control.
Response:
v=0
o=- 1284464363092904 1284464363092904 IN IP4 axis
s=Multicast presentation
e=NONE
t=0 0
a=range:npt=0.000000-
m=video 50000 RTP/AVP 96
c=IN IP4 239.225.149.138/0
b=AS:50000
a=framerate:25.0
a=transform:1,0,0;0,1,0;0,0,1
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1; profile-level-id=420029;
sprop-parameter-sets=Z0IAKeKQFgJNgScFAQXh4kRU,aM48gA==
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