What is Real Time Video Overlay?
What is real time video overlay?
Displaying live video information is an important job in demanding AV projects. Video information may come from multiple sources (such as media players, satellite receivers, video cameras, different PCs) that are directly connected to the monitors or a device managing the visualization.
The live video must be displayed on a single monitor, over multiple monitors or over the large coherent screen of a video wall. In case of multiple video sources and multiple monitors splitters, selector devices, matrix switchers or video processors handle the video inputs and drive the output monitor screens.
What is the definition of real time video?
The real time video definition means immediate display of live video information, without any delay, meaning no latency in time and no quality dropping. This is critical for control and supervision projects, regardless of video format, frame rate or number of outputs where content is displayed.
Even scaling up of video signal cannot result in delayed visualization. If in the given application, only pre-recorded content is being displayed, real time video is not required – as these applications generally give room to a couple seconds of delay in terms of their displayed video content.
Where do we meet real time video in the pro AV industry?
AV system integrators must serve different customer needs in each AV project so must carefully select input devices, video processing equipment, connections and the output monitors. Large variety of projects may need video visualization for board rooms, show rooms, university halls, conference centers, traffic supervision, mission critical control room applications. But the customer requirements definitely differ and need different solution for the video visualization.
The most demanding AV projects and applications need video display in real time. This means no delay between the event and the video display about the event. This is called real time display and must be applied for applications where the operators must be informed about status or changes immediately. This is a general requirement in control rooms or traffic control centers where the operators must react to process changes or to important alerts immediately. There is no room to lose seconds in these critical situations.
What is real time video overlay?
In AV projects serving control rooms with video wall the video information must be combined with other graphics information that are the background to be displayed over the video wall. The graphics information may contain mapping application that displays a certain map of a selected area or may display statistical information about an industrial process by a SCADA system.
This graphics information forms the background. The video information usually displays the live video content over this background in the selected positions and in the required size.
We call this as video overlay that displays real time video information as addition to the background graphics. This quite advanced service is a must in demanding AV projects and gives perfect service for the operation. DEXON Systems offers video wall controller solutions that complete this task unprecedentedly.
How does real time video overlay work in practice?
Basically, there is a controller or a video processor in the center of this process. All video sources are connected to such a device that is capable to display the graphics background and live video overlays. Such video contents can originate from directly connected HDMI, HDBaseT, composite video, component video and SDI input connections.
The inputs signals must be processed, format converted scaled, cropped and displayed in the desired position and size. These overlay inputs can overlap with the graphics windows as well as each other. This function allows operators to share content over a video wall from multiple sources and despite of these inputs coming from different sources, a well-designed video wall controller is capable of handling the overlay of these contents.
This means that we can display media players, satellite receivers, Blu-ray players or even PC outputs displaying operator workstations’ screens. Thus, the video wall has a combined function displaying Windows graphics and overlays from different inputs simultaneously.
For example, a device contains two output signal scaling engines for each of the output channels. The scaling operation has no limit so the scale up from any input resolution as for example 640x480 or 1024x768 to any output resolution up to 1920x108, 3840x2160 or even 4098x2160 are possible.
Scaling down from any input resolution as for example 3840x2106 can be performed to any output resolution as 1290x720 is possible. One of the scaling engines serves the main output while the second one supports the PIP channel. The scaling operation results in crystal clear image in real time with no drop of frames over the video wall.
DEXON’s presentation matrices perform all operations in real time. Thus, the output signals are displayed in real time from the inputs regardless of the signal resolution, scaling, PIP and number of signals controlled. No drop of frames, nor black frames or transitions can be experienced.
DEXON also provides video wall controller solutions to the AV market that drive multiple screens to form a large Windows graphics desktop where graphics and live video overlay windows are displayed in real time.
Where do we use real time video overlay?
This function is widely used in mission critical control rooms, crisis centers, network operation centers, traffic, police and command control centers. In these application areas, there is generally a large video wall displaying an enormous amount of data that come from locally running applications or different operator PCs. These operators all have different accesses to display information over the video wall, usually from different sources.
Therefore, it is vital for a controller to allow multiple operators to share critical content on a common video wall. In such control rooms, quick information handling, most importantly real time content sharing, is rather important to allow decision makers to have a great overview of critical information. This information needs to be excellent quality and real time display.
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