VOCORD Tahion can simultaneously process several video streams from one camera. For example, one of the streams can be recorded into the archive, another can be displayed on the operator’s screen. But processing several video streams from one camera requires high network capacity.
When a large number of channels is to be displayed, each channel will be displayed for view in a small window where the details cannot be seen. Tahion solves this problem by supporting several formats of streaming video from the camera in the live video regime. If a large number of channels are displayed, Tahion automatically retrieves from the camera a low resolution video stream; when the channel is maximized, it automatically switches to high resolution not to lose the details.
To improve the quality of video VOCORD Tahion uses several visual filters:
> Contrast increase. This filter will help to obtain an image of proper quality, even if the video was recorded in poor lighting, for example, on the dark parking site.
> Deinterlacing. To avoid the “comb effect”, occurring when the interlaced video is streamed, VOCORD Tahion uses filters of deinterlacing, which considerably enhance the quality of images, obtained from analogue cameras. The high quality is ensured by means of the unique technology of field combination, developed in the Vocord company.
When video fast forward is switched on, the load on hard drives in the video surveillance systems is increased, which might lead to the overload of the equipment. The human eye is not able to follow the number of shots per second displayed in the fast forward regime. VOCORD Tahion automatically “thins out” the video stream, balancing between the possibilities of the human eye, the productivity of the system of storing data and the network, and the tasks of the surveillance system.
In large-scale projects, especially in “Safe city” projects, different parts of the video surveillance system may be administered by various organizations. It implies that every organization can have access only to its part of the system, while the parent organization will have access to all the parts of the system. In such cases the architecture of the video surveillance system can be built on the basis of domain hierarchy.
Every domain is a fully functional system, which can work autonomously, without being connected with the outer world. Several domains can be united into an integral system, whose domains may have hierarchical relationship. The users of higher level domains receive access to low level domains. Low level domains do not have to know about the existence of the higher domains. If connection between the domains fails, each of them will continue working independently; when connection is restored, the system will automatically restore hierarchy.
In most video surveillance systems connection is established directly: a video stream is simultaneously requested by many operators, recorded into the archive, transmitted to the video wall, etc. This results into a heavy load in one communication channel, which can lead to data loss or affect the quality of video shots when transmitting the video stream. The system VOCORD Tahion has a stream router - program component Tahion NetScale. It establishes one connection with the video channel and distributes data on every request.
Tahion NetScale was conceived as a route of the application layer for transmitting video data: it does not only transmit data, but also analyzes their structure. In any video surveillance system, when data are transmitted, every shot is split in IP-packages. When protocols with non-guaranteed delivery (UDP, RTP) are used, part of the packages can be lost, when, for example, the load on IP-network increases locally. As a result, the user receives low quality shots (with “artefacts”). Such video recordings cannot be used, for example, as evidence in court.
Unlike ordinary routers, Tahion NetScale “understands” which IP-packages make up one shot. If the network load is heavy, it will let pass those packages that make up one shot. Thus, the video stream will be with a lower frequency of shots, but all shots in it will remain unbroken – the image will have no “artefacts”.
The maximum amount of data that Tahion NetScale can process is limited by hardware possibilities of the server only.
Cloud architecture of storing data VOCORD Tahion allows to use an unlimited number of remote physical archives, virtually uniting them into a unified system of storing data. Uniting occurs unnoticed by users – they work will all archives as if it was one large archive, without having to connect to different servers in order to see different recordings. This architecture allows to save on video surveillance systems, as it is not necessary to buy expensive professional data storing systems.
Flexible configuration of recording
VOCORD Tahion allows to flexibly configure recording into the archive: different video channels can be recorded into different archives with a different frequency of shots and stored for a different period of time. For example, for many sites it is relevant to record a long-term archive with low fps, but if detectors are triggered, to record into the alarm archive with an increased fps. Working with the archive, the system will automatically switch to recording with a higher fps. It allows to optimize volumes of stored information and reduce expenses on hard drives, which often make up for the largest part of the budget allocated for the entire video surveillance complex.
Metafile system Tahion IntelliStore
Usually video recording systems store metadata either inside files with video data or near these files. But for the system the scenarios of working with video data are considerably different from those of working with metadata. While in the first case it is necessary to process large volumes of stream video, in the second case a small amount of server-based data is dealt with. To accelerate the work of the video recording subsystem VOCORD Tahion the unique technology IntelliStore is used – it employs its own metafile system over the standard NTFS. This technology allows to record meta data on a separate disc and read this type data separately from video data, which considerably accelerates work with the video in the archive. Besides, it ensures zero fragmentation of discs, even if re-recorded multiple times.
Working with a large number of channels in the archive in some video surveillance systems leads to difficulties because of desynchronization of video streams between different channels. In this case the operator will have difficulty reconstructing the actual course of events. The technologies realized in the VOCORD Tahion guarantee synchronous video playback for all the cameras: regardless of their number, in any video format, at any moment of time and for any playback time in any direction.