ONVIF PTZ camera with two streams may display as two different cameras even if “Manage all streams as quality” is checked. This is because the XML is reporting the secondary context as being an independent PTZ which is something generally used for fisheyes where PTZing one stream doesn’t PTZ the other streams.
Multistreaming provides the ability to display or record camera video streams at alternative settings for a number of different use cases. Examples include:
Displaying higher resolution video to users on the local network than those connected remotely to constrain bandwidth consumption. This is achieved through Auto-Context Switching, described below.
Recording high resolution streams while displaying lower resolution to live viewing workstations, ensuring forensic searches provide the greatest level of detail. This is achieved by simply using different recording schedules for each stream.
NOTE: Multistreaming is not available for exacqVision Start users and your cameras must support multistreaming. Refer to the IP Camera Integration database to search for supported camera models.
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Adding Streams
In the cameras Settings page, use the ‘Add Stream‘ button to create a secondary context stream and make any changes to the recording quality or frame rate settings.
The resulting secondary stream will appear nested under the primary stream on the configuration tree. Here, it’s been given a name to indicate it is the lower resolution.
TIP: Cameras typically provide fewer settings options with each additional stream. Typically, you want to select the lowest context number available since most cameras provide less settings options as the stream number increases. As an example, a 4MP camera may provide 4MP for the primary stream, but the secondary stream may not be set above 2MP. Some fisheye cameras may only provide camera-side dewarped options.
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Auto-Context Switching
The exacqVision Client has the built-in capability to select the best stream for your display panel based on the scale of the video display and connection speed. This can be used to help optimize performance in the client.
Example: You have a camera configured with a high resolution primary stream but also have a low resolution secondary stream. Auto-Context Switching by the Client will select whether to display the low or high resolution stream based on the size of the image in the client or connection speed. This results in improved bandwidth utilization and performance when viewing multiple camera streams in Live View or connected over a slower remote network.
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Managing Streams as Quality Streams
Auto-Context Switching takes place automatically if the sub-stream(s) are in the same aspect ratio; e.g. – 16:9 to 16:9, or 4:3 to 4:3. This does not take place automatically if they are of different aspect ratios, such as a 16:9 primary and a 4:3 secondary, or in cases where the FOV has been cropped. However, the exacqVision Client provides some settings for controlling this behavior as well as the appearance.
Navigate to the Client Settings.
Under the Multistreaming dialogue, enabling ‘Manage All Streams as Quality Streams‘ will override the default behavior to perform Auto-Context Switching regardless of aspect ratios. Note, that this could lead to distinguishable changes in the Live display based on the aspect ratio of the camera panel grid when the streams have different dimensions.
In Live View parent devices are shown using a purple icon, with the context streams nested beneath them shown with blue icons if you are using the Light or Dark themes. When using the Classic theme, the parent device will now be shown with a gold asterisk.
Drag the primary device name to a panel. This contains both the high and low resolution streams. The exacqVision Client software will automatically determine which stream to display based on the panel size.
This can be observed by first using a layout in which camera panels are small in size, such as the 5×5 layout shown below. Note that the stream named ‘(Low Res)’ has been selected and view the data rate at the bottom.
When changing the display to the single panel layout, the Client software automatically switches to the full resolution stream and the data rate at the bottom increases.
Besides changing the size of the panels by changing the layout, this can also be observed when resizing the Client window, particularly when viewing the single panel layout.
In addition to panel size as a factor, exacqVision will also consider the connection speed of the Client to the Server. This is manually configured when connecting to a server on the Add Systems page. Located beneath the server address and login credentials, this setting defaults to LAN. But users connected offsite may benefit from selecting the proper setting.
Local – Should be reserved for instances of the Client being run directly on the NVR hosting the exacqVision Server.
LAN – Used by workstations on the same local network, typically within the same building and without routers between the workstation and NVR.
WAN – Used by workstations on a wide area network, say on a municipal or university network, or even across town.
Remote – Used by workstations connected further away over several router hops, or with bandwidth limitations between the Client and NVR. Also encouraged if connected to remote exacqVision Edge applications using a cellular/wireless connection.
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Hiding Quality Streams
By default the Live Cameras tree will display all configured streams, as seen in this example.
Some users may not wish to see the secondary context streams listed under their cameras in the Live Cameras tree. These may be hidden by entering the Client settings page and enabling the ‘Hide Individual Quality Streams‘ setting.
With this enabled, returning to the Live Cameras screen shows only the parent stream, managed automatically by the Client as described above using Auto-Context switching.