PlayBox Video Playout Servers

Tuesday, May 25, 2010

The Ampex Corporation’s invention of the videotape recorder in 1956 changed the television industry. Videotape, in various formats, was the industry’s only large-scale recoding medium for programme delivery into the 21 Century. It survived for 50 years – an amazingly long time. Unlike the hard disc drives that have now largely replaced videotape, it was designed specifically to meet the needs of the industry it served. It recorded television in real time and linearly. Indeed the first VTR format, Quadruplex, the 2-inch wide tape could be cut-edited like film.

The use of hard disc drives to record video was not as straightforward as this storage medium was designed to record and play small, separate chunks of data, not television’s continuous flow of high-speed data. It took considerable research and development effort to learn how to operate the drives and arrange and handle the data storage so that continuous recording and playback could be achieved – not just for low bit-rate home viewing but for broadcasters who absolutely depend on reliability and need high bit rates even for handling compressed video.
Because of the complexity the first reliable professional disc-based recorders and servers were driven by proprietary dedicated hardware. They provided the required high performance, but came with an equally high price. So, ten years ago, PlayBox Technology brand was established by the Bulgarian company Digital Media Technologies to create video playout systems that used the much lower-priced IT hardware platforms. Central to its product range then was the AirBox playout server that provides automation and video replay from a PC platform. That same AirBox is still PlayBox’s playout server, albeit with a multitude for revisions and additions, all the way to HD. The decade of experience and R&D has been used to grow the AirBox platform with features and reliability. But a video playout server has to do much more than play video.
Formats, formats, formats!
Video servers are one of the main places that the IT and video industries meet. Video has lived by industry standards so broadcast television has been ‘plug-and-play’ since long before the PC was invented. The broadcast industry had many concerns when IT technology became involved with television. One of them was that IT used any number of file formats – many ‘de facto’ standards were not standardised at all. Much early digital video equipment used the manufacturer’s preferred ‘pet’ format. They were not so much of a problem as the video inputs and outputs were of broadcast standards. But soon people wanted to exchange video over computer networks, and then those ‘pet’ formats became a problem for another company to handle.
Ten years ago, being a small, new company, Digital Media Technologies (DMT) knew that its systems would depend on file exchange with equipment from other companies, and that no broadcaster wanted another format in the market. So PlayBox developed interfaces for all the major file formats in use... and many of the not-so-major ones too. This effort paid off as AirBox can be plugged straight into just about anyone’s existing digital video store and directly read the files.
This is of great importance to all broadcasters who are using any disc-based video storage – so just about everyone! For example, what happens if a new playout system cannot directly read a TV station’s video archive? The only solution is to play it out as baseband SDI video and re-record it into the new playout system’s format. This prospect was facing one broadcaster, who was concerned that making the transfers of his 1000-hour archive would cost far more than the new equipment. After over a year of searching PlayBox said ‘no problem’. The engineering manager didn’t believe it, so AirBox was plugged into the archive, and, of course, read the files in the ‘pet’ format directly – saving the cost of transfers and the loss of quality in the decode-recode cycle.
Another common situation is that a TV channel, which has nonlinear editing, cannot exchange files with the digital playout system. The solution is to replay the completed programmes from the edit area as SDI, and ingest that into the playout area. This has to be real time, involves staff to log the process and check it’s worked correctly. So it’s expensive and relatively slow.
The ability to handle all common file formats has enabled PlayBox to solve these problems and complete the much sort-after ‘file-based tapeless’ workflow. Some of the benefits are clear from the mentioned examples. Moving media becomes a trivial operation that can happen faster than real time, involves very little operator time and comes free with the system! In addition the media arrives in pristine condition so the best possible quality pictures and sound are broadcasted.
Equally important are control and data interfaces into the stations equipment. Most installations are at existing stations with established ways of working and operations such as traffic management and scheduling already in place. Interfacing with these is often essential and can require a little engineering. 
Boxes or solutions?

For DMT/PlayBox Technology (PBT), the AirBox provides playout for SD, HD and DVB (ASI/IP), as well as automation. It can be used on its own as it includes its own media storage, but what most broadcasters want is a complete playout solution to run their channels on air. AirBox is just one of the many modules available from PlayBox to provide the required services for a complete playout solution. This may be supplied as a compact economic ‘channel in a box’ or as several separate boxes, according to requirements.

The size of storage within the AirBox frame can be chosen according to the volume of programming it is required to hold for days or weeks ahead. Most playout systems also include a larger networked shared storage in the form of a NAS. Again the size is the customer’s choice. In all cases the storage can be protected against single points of failure by using a RAID configuration.
AirBox includes station logo (bug) insertion on its output, but if you want more graphics then the TitleBox graphics server is available. This offers the preparation of graphics templates that define the on-screen look of the graphics, as well as presenting live animated multi-layer graphics, that can include solid 3D objects and text on air. Once again interfaces add to the capabilities such as accepting SMS text message as well as live database feeds allowing, for example, sports scores or financial updates live on screen, and fully automated. AirBox and TitleBox can work closely together, with AirBox automation cuing TitleBox events, and keying the graphics over replayed, or even live video.
CaptureBox is an ingest server that accepts analogue or digital SDI or compressed video in SD, HD or ASI/IP, and converts it into a chosen digital file format. It includes RS422 serial control for video players, and can be run manually, or automatically for batch or scheduled operation.
SafeBox provides automated content management. It orchestrates the movement of media through the playout system to the AirBox for playout. It can examine playlists and check if the required media is in the AirBox at a defined period prior to transmission time. If it is not it searches the system for it. If it does not exist it creates a message warning of the missing media.
DataBox is a universal metadata description tool able to operate with data from archives to run-time copy with all types of categories. This greatly assists searching and finding wanted media. ListBox is for creating programme schedules days, weeks or months ahead and can make use of DataBox to help find the required media.
Subtitling is handled by two modules SubtitlePlus and SubtitleBox. Together these provide for the preparation and, where required, the burning in, of subtitles over a wide range of languages for all common applications, included closed captioning, DVB and DVD authoring. AirBox can accept subtitle files and play them on air in sync with the video.
CaptureBox Compliance offers means to make a full record of channel output and can compress the video to 1 Mb/s to hold up to 90 days of 24/7 recording. Tools help to organise and find required material.
Customers are free to choose the modules that they need and, where appropriate, these and more available modules, all integrated to make a fully operational playout solution. PlayBox also knows that, for many, it is important to integrate with services and file systems at any existing location. Also installations may require third-party products. These can all be included in a turnkey system.
Enhanced reliability

Where required, there are a number of steps that can be taken to make server operation less liable to the effects of component failure. Redundancy is available in several forms. As already mentioned, disc storage can be configured into a RAID so that the failure of one disc drive will not cause the loss of any data. Another step is to add one or two extra power supplies into the equipment chassis to maintain operation if a supply fails.

Often there is a second, fully redundant AirBox and TitleBox server operating in parallel with the main server. These two are identical and have the same media storage and configuration of modules. 
A way to avoid a small problem becoming a big one is to have alarm reporting. AlarmBox can monitor operations and send reports via services such as email and SMS.
Remote operation

Perhaps the clearest illustration of the potential capabilities of PlayBox playout solutions is their use in unattended remote playout applications. The remotes can be fully serviced from their associated broadcast centre by Internet. This saves money by avoiding the costs of dedicated fibre or satellite links and allows the remote to be placed anywhere a good Internet connection is available.

Operation is totally dependant on automation and the system has to be built to work with the Media Assets Management and file formats of the broadcast centre. The systems usually have full redundancy. Such remote stations have been in operation for over a year now and are a clear demonstration of the quality and reliability that has been achieved today. This contrasts sharply with the doubts of ten years ago when some believed that IT-based solutions were not powerful or reliable enough for broadcast professionals. Now, times have changed. Commodity, off-the-shelf IT equipment has enormously increased in power, capacity and speed and many thousands of TV channels are now playing out to air using IT-based platforms from PlayBox. This alone does not mean all IT solutions will work well. Firstly the software has to be proven, easy to use and reliable; and secondly there will always be endless variations in exactly what the PC open platform’s hardware, firmware and software actually is. Turnkey solutions with good software and IT hardware, built to defined specifications and tested before delivery, have proved to be very successful. The resulting ‘broadcast performance at IT prices’ represents a big difference in buying and running costs, and not at the cost of performance capabilities.