Video server The tvSuite as the output module of system for organization of the off-the-air broadcasting built with application of network technologies

By Rodion Chugunov

Review contents:

Network solutions in TV production Network solutions of company Avid for broadcasting and video production Automation of broadcasting: DIP solutions Networking for live television production Solutions of the JC System Integration Company VSN — all in one Network disk arrays of company Maxtronic Network file-based broadcasting with On-Air Central Video server The tvSuite as the output module of system for organization of the off-the-air broadcasting built with application of network technologies Network solutions for program-making on the basis of Pinnacle Liquid systems Network production from Sony Network solutions Vectorbox

The tendency of the broadcasting transferring to the tapeless technology outlined recently and fast increasing of throughput of local computer networks have resulted to that in Russia not only large broadcast corporations, which annual budget is equal to some hundreds thousand dollars, but also the small regional companies with the budget equal to some tens thousand dollars, try to find such technical solutions which will allow them to solve questions of the automated TV broadcasting, managing without intermediate copying of a ready material to magnetic tape.

It is quite natural, that search of such solutions on the basis of the program and hardware systems developed by the western manufacturers, not always may to be successful. The price in some thousands US dollars for a system for them at times happens simply inaccessible though any west local cable TV studio can spend in 5…10 times more for realization of similar problems.

Inoccupation of the segment of the TV equipment and solutions for the organization of TV broadcasting at the Russian market has resulted to that situation when some Russian manufacturers and suppliers of the software has put the problem to offer to the consumer the hardware-software solution allowing at low cost to organize process of automated TV broadcasting under renunciation of the tape, with the organization of information interchange over local computer networks, having left as the initial stage the operation “pumping” of original video and audio from magnetic media.

The server solutions of off-the-air broadcasting PlayBox and AirBox and also the software “TV”, allowing to automate of off-the-air broadcasting in network version without high expenses, are well-known. However these hardware-software solutions mean an application of the additional equipment, firstly intended for synchronization and switching of external and internal program sources, that in a case of the advertising and news inserts in the reference channel conducts to the significant rising in price of system as a whole, especially in the case when the broadcasting complex is not installed in production studio directly, but territorially removed from it — for example, is located at RTC territory.

The block diagram of a standard complex for the organization of local broadcasting thus will look like, shown on the figure, and in the most cases the presence of the air operator supervising the video server operation is necessary.

Essential cost reduction of the equipment complex for the organization of off-the-air broadcasting is possible with the help of the video server software The tvSuite version 3, specially intended for operation with transmitted video signal. Thus the overall economy due to absence of devices for synchronization of external and internal program sources makes approximately 30…40%, and additional software allows to carry out not only playback of the video information under prepared off-the-air schedule, but also to fit the graphic information into video signal, for example the channel logo, without use of additional devices.

Being a logic development of the previous version of software The tvSuite, version 3 is specially developed in view of the requirements of users which are the regional broadcasters including the information in a signal, receiving from the external channel in certain time according to the broadcasting schedule, and allows to use a mode of the remote access with the help of additional standard software of remote access, for example Remote Admin.

The analysis of the local network operation under transmission of stream video shows, what even in the case of Gigabit Ethernet using there are no guarantee of playback without detriments.

Specificity is in that in the most cases the broadcasting of files over a network is critical to the rate.

So, for example, the transmission over Gigabit Ethernet network of five streams 25 Mbit/sec (codec DV25) simultaneously, that is possible under simultaneous playback of stream video in the air and editing from two NLE stations using a uniform file, results in average bit rate approximately 100 MB/sec, and, that it is more terrible, — to short-term “subsidences” of video transmission rate up to 5…7 Mbit/sec and, as consequence, to detriments in case of the multiuser access over network. Only using of three and less independent streams provides a guarantee of DV25 stream video transmission. It is illustrated by the following figure.

Due to occurrence of short-term “subsidences” even under playback of one DV25 stream the application of the network 100BaseT Ethernet is inadmissible (see fig.)

In view of these restrictions the software of the server of off-the-air broadcasting The tvSuite version 3 means the layout of the playback material on the local array of data storage which are taking place in the server structure. The organization of operative recording of the information in array under multiuser mode is possible, thus the limiting number of streams will be determined only by throughput of the given local array.

The features of the remote editing or creation of the playlists, the same way as the remote control of additional functions, for example, by insert of the graphic information, are depended from network throughput and for Gigabit Ethernet are carried out in a mode of real time.

To the basic advantages of the software it is necessary to attribute, first of all, a mode of dynamic escalating of playlists and high stability at working-off of the large number of off-the-air schedules (up to 1000 clips, 50 blocks and sub-blocks). The mode of dynamic escalating of the playlists allows to use preliminary composed repeating blocks under operative escalating of off-the-air broadcasting playlist without broadcast stopping, and application of the local array into server hardware enables steadily reproduce the stream video even during the exchange of information with server over a network.

Material provided by Ovako Company