Onvif Replay Extension

The VAPIX® Onvif Replay Extension API makes it possible to receive a Real-time Transport Protocol (RTP) header extension with a Network Time Protocol (NTP) timestamp for video and/or audio streams on an Axis device. param.cgi can be used to enable Real-Time Streaming Protocol (RTSP) parameters as a default. Use cases include mapping a metadata object with a timestamp into a video frame within a video stream. The Onvif Streaming specification specifies the RTP header extension.

Identification

• Property: Properties.API.RTP.OnvifReplayExt
• Firmware: 10.11 and later

Example

Check if the feature is supported. On an open terminal, send the following HTTP GET request to param.cgi:

curl --digest --user root:pass 'http://<ip>/axis-cgi/param.cgi?action=list&group=Properties.API.RTP.OnvifReplayExt'

A correct response will contain the property "Properties.API.RTP.OnvifReplayExt=yes".

Use cases

Retrieve video stream

Enable Onvif Replay Extension with the RTSP setup. NTP timestamps will be included in the RTP packets and the client can use them to map frames to metadata objects, synchronize video from different cameras, etc. RTP header extensions are enabled if the RTSP parameter is used.

Example

Open a streaming application, such as VLC, and a network URL (Media -> Open Network Stream):

rtsp://root:pass@<ip>:554/axis-media/media.amp?videocodec=h264&onvifreplayext=1

Check the network with, for example, a wireshark for an RTP header extension. This can also be used if you want to disable the feature in case it was enabled by default:

rtsp://root:pass@<ip>:554/axis-media/media.amp?videocodec=h264&onvifreplayext=0

Retrieve default values

Check if the RTP header extension is enabled by default. If it is, the feature will be used even if the RTSP setup doesn't contain any extra parameters.

Example

Check if the feature is enabled by default. On an open terminal, send the following HTTP GET request to param.cgi:

curl --digest --user root:pass 'http://<ip>/axis-cgi/param.cgi?action=list&group=Network.RTP.OnvifReplayExt'

If the feature is supported, the response will contain Network.RTP.OnvifReplayExt=yes.

Enable Onvif Replay Extension

Enable or disable the RTP header extension by default.

Example

Enable or disable the feature by default. On an open terminal, send the following HTTP GET request to param.cgi:

curl --digest --user root:pass 'http://<ip>/axis-cgi/param.cgi?action=update&Network.RTP.OnvifReplayExt=yes'

API specifications

Check if the feature is supported

Check if RTP with the OnvifReplayExt feature is supported.

Request

GET /param.cgi?action=list&group=Properties.API.RTP.OnvifReplayExt

Parameter	Available values	Description
action=<string>	list	The parameter action.
group=<string>	Properties.API.RTP.OnvifReplayExt	The parameter group name.

Responses

200 OK

Example value

Properties.API.RTP.OnvifReplayExt=yes

Schema

Feature is supported

{
    [
        Properties.API.RTP.OnvifReplayExt=yes
    ]
}

Feature is not supported

{
    [
        # Error: Error -1 getting param in group 'Properties.API.RTP.OnvifReplayExt'
    ]
}

Check if the feature is enabled by default

Check if RTP with the OnvifReplayExt feature is enabled by default.

Request

GET /param.cgi?action=list&group=Network.RTP.OnvifReplayExt

Parameter	Available values	Description
action=<string>	list	The parameter action.
group=<string>	Network.RTP.OnvifReplayExt	The parameter group name.

Responses

200 OK

Example value

Network.RTP.OnvifReplayExt=yes

Schema

Feature is enabled

{
    [
        Network.RTP.OnvifReplayExt=yes
    ]
}

Feature is disabled

{
    [
        Network.RTP.OnvifReplayExt=no
    ]
}

Feature is not supported

{
    [
        # Error: Error -1 getting param in group 'Network.RTP.OnvifReplayExt'
    ]
}

Enable or disable the feature by default

Enable RTP with the OnvifReplayExt feature by default.

Request

GET /param.cgi?action=update&Network.RTP.OnvifReplayExt=yes

Parameter	Available values	Description
action=<string>	update	The parameter action.
Network.RTP.OnvifReplayExt=<string>	yes, no	The new default value for Network.RTP.OnvifReplayExt.

Responses

200 OK

Example value

OK

Schema

Value is updated

{
    [
        OK
    ]
}

Feature is not supported

{
    [
        # Error: Error setting 'root.Network.RTP.OnvifReplayExt' to 'yes'!
    ]
}