*Devices - Streaming
Configuration Article | CA-20210521-MH-01 VDG Sense | Setup | Devices | Multi Streaming |
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Introduction
The Streaming tab is used to configure specific Sense settings needed for using different streams (profiles) as configured on the camera. It is very common practice to use high resolution (for recording) and low resolution (for live viewing and VCA) streams simultaneously. Within Sense this concept is called multi streaming.
Also this tab is used to configure multicast settings in case multicast streaming is needed.
Multi Streaming
Multi streaming is used when layouts contain many video panels, such as multi‑monitor Videowall setups in control rooms.
Decoding compressed video (H.264/H.265) is CPU‑intensive, especially at high resolutions. Each system has a maximum number of pixels it can process per second; if this is exceeded, stuttering and frame skips may occur. With many simultaneous Full HD or higher streams, this limit is quickly reached.
To prevent this, low‑resolution streams are typically used when many panels are shown in one layout. Because the image is already downscaled to small panels, the lower resolution is barely noticeable to the viewer.
In Sense, this concept is called “Multi streaming”. It allows recording the high‑resolution stream while using either the low‑ or high‑resolution stream for live viewing, depending on the video panel width in the layout.
When VCA (Motion, SceneR, CarR, Siqura VCA (ObjectR), ObjectC) is used, you can also select which stream it uses. VCA usually works fine on lower‑resolution streams, further reducing CPU load.
All settings related to “Multi streaming” can be found under the “Devices” → “Streaming” tab. See also screenshot below.
Note: For selected camera drivers, triple streaming is supported. This means VDG Sense can use a third stream for either recording, displaying or VCA.
Enable multi streaming
Enables multi streaming for selected device.
Record
Select which stream must be used for recording.
VCA
Select which stream must be used for VCA (Motion, SceneR, CarR, Siqura VCA (ObjectR), ObjectC).
Multi stream settings
Stream Profile
For some cameras it is required that the stream profile is entered here. See this article for more information: https://tkhsecurity.atlassian.net/wiki/spaces/KB/pages/9168946058
Max panel width
This setting determines which stream will be displayed in the video panel on the layout. It is the maximum panel width (in pixels) for which the stream will be used.
In the screenshot below the “Max panel width” for “Stream 2” is set to 800. This means that all video panels that have a width that is 800 pixels or lower will use “Stream 2” as the video stream to display. All video panels that have a width that is bigger then 800 pixels will use “Stream 1” as the video stream to display.
It is advised to set the value for “Max panel width” slightly higher than the actual setting of the video stream as configured in the camera.
For instance if the second stream in the camera is configured as 720x576 resolution, you can set the “Max panel width” to 800. In that case all video panels that have a width that is 800 pixels or lower will use the 720x576 stream to display.
It is possible to check the actual resolution being displayed in a video panel by enabling the “Resolution”-option in the “OSD Style” of the panel. When enabled it will show the actual resolution of the stream in the OSD bar at the bottom of the video panel. See also: OSD Style.
Stream settings
Normally all camera settings (including stream settings) are configured directly in camera. E.g. via camera webpage or some tool. Sense will then ‘follow’ these settings.
However for a limited set of device drivers Sense can read and write the stream settings as shown in screenshot below.
Following drivers currently support this:
TKH Security Solutions 1000/1100
Siqura Megapixel
Skilleye
VDG
Grundig
Dynacolor
Hikvision
These settings are:
Resolution (in pixels)
Resolution of the selected stream. All supported resolutions for that specific camera will be available in the selection list.
Framerate (in fps)
Framerate of the selected stream. All supported framerates for that specific camera will be available in the selection list.
GOV (in frames)
GOV of the selected stream.
Bitrate (in kbit/s)
Bitrate (bandwidth) of the selected stream.
IMPORTANT
For the device drivers as mentioned above the “Framerate”-setting will no longer be available on the Profiles → General tab. It can only be changed on this (Device → Streaming) tab.
Macros
Note that the stream settings as mentioned above can also be set via server or viewer macro action. Macro source type is “Video”.
See example below for setting the Resolution on Stream 2.
** EVERYTHING BELOW THIS LINE IS UNDER CONSTRUCTION **
Multicast settings
Enable Multicast
Enables multicast for the selected stream.
Note: There are 4 variants possible for the multicast settings. What is shown in Sense depends on the selected device driver. See below examples and description of the 4 possible variants.
First it is important to mention that Sense supports 3 multicast modes. See below.
RTSP (auto)
When this option is enabled the “Multicast Address” and “Multicast Port” edit boxes are grayed out (read only). This is because the Sense client will use the RTSP protocol to request multicast settings directly from camera. In this mode Sense ‘follows’ the camera.
RTSP (manual)
When this option is enabled the “Multicast Address” and “Multicast Port” edit boxes must be filled in correctly by the Sense administrator. The Sense client will use the RTSP protocol to ‘write’ these settings into camera. In this mode camera ‘follows’ Sense.
Passive
When this option is enabled the “Multicast Address” and “Multicast Port” edit boxes must be filled in correctly by the Sense administrator. These settings must match the settings as configured inside camera. No negotiation (via RTSP protocol) between Sense client and camera is done in this case. It is assumed that camera multicast stream is active and camera is sending video data to multicast group. Sense will only send IGMP join using the configured “Multicast Address” and “Multicast Port” values. In this mode Sense ‘follows’ the camera.
Based on the 3 multicast modes above Sense can show 4 possible variants. See below.
Variant 1: Only RTSP (auto)
Variant 2: Only RTSP (manual)
Variant 3: RTSP (auto) or RTSP (manual)
Note: “RTSP (manual)” multicast mode is active in this example.
Variant 4: RTSP (auto) or Passive
Note: “Passive” multicast mode is active in this example.