Channel Explosion Turns Broadcast Monitors On Their Head
Grass Valley Kaleido-IP multiviewer.
When most people think of broadcast video monitors, they think of a very expensive, precision television display used to view and judge the quality of broadcast images. Engineers — often nicknamed “Golden Eyes” — assess the TV signal based on years of skill, knowledge and human intuition.
Such video monitors still exist, especially in the network and cinema production environment. However, in a world with an exploding number of broadcast channels, single monitors are no longer adequate in many control rooms to check the quality of broadcast signals.
In today’s studio, single monitors have been largely replaced by a video monitor wall, with displays for program feeds, preview, video servers, cameras, graphics and other sources. In some facilities, the monitor wall is a series of racks containing physical television and computer monitors; in others, it has been replaced with a virtual monitor wall — often called a "glass cockpit." Such walls consist of one or more large video screens, each capable of displaying multiple channel sources in a simulation of a traditional monitor wall.
Because of the large number of video sources in a typical control room, stations are increasingly moving to monitor walls. These display systems are user-configurable and support the display of many video signals, often with overlaid audio and data information.
Such walls are necessary due to a constantly growing number of channels. The “eyeballing” of picture monitors is no longer an adequate method for determining network performance. Today’s multichannel environments process far too much information — whether it be video, surround audio, language options and data services (or combination thereof) — for operators to properly monitor the quality of the signal and integrity of program feeds.
Human observers might be able to pick out video impairments while watching several monitors. However, even if they can find an error among hundreds of channels, identifying the root cause of the impairment is impossible through visual inspection alone.
Along with the technology used to break televisions signals into multiple virtual monitors on walls, another technology is required to detect and automatically alert operators to problems such as bit rate loss, picture artifacts, frozen images, audio mix-ups and missing subtitles. Monitoring also must be available at remote locations, such as in central casting models, and easily interpreted by non-technical staff members whose responsibility covers a myriad of tasks.
Several companies now make products that can detect protocol errors and measure statistics within the MPEG transport stream. Modules are used to measure PID bandwidth, PCR Jitter, T-STD buffer statistics and SI table compliance.
Video quality monitoring can detect freeze frames, momentary picture changes, blockiness, loss of color and overall video quality through the use of an algorithm. Audio is measured for technical defects, as well as human mistakes such as having the wrong language playing on the air. Logs are generated from errors so documentation is available in case of contractual disputes.
Single monitors now used in television facilities may or may not be broadcast quality. Some broadcasters purchase low-cost LED monitors to view the output of a video-generating device, such as playout from a video server, IRD, video camera, VCR or DVD player. They may not be professional quality and simply are used for confidence checking of analog signal and digital signals throughout a system.
The other side of the coin are high-quality single monitors like Sony’s BVME250A 25-inch Trimaster EL OLED master monitor, which is priced at $26,000. OLED (organic light-emitting diode) monitors are now often used for high-end monitoring applications.
The Sony BVME250A Trimaster EL OLED master monitor provides precision and high resolution imaging along with a menu of options including, multiple scan modes, assignable key functions and user LUT ingest.
As well as offering specs superior to CRT monitors, this monitor almost completely eliminates any shading or off axis color shift. These units have accurate black representation and color reproduction, precision imaging without artifacts, stability, consistency and quick response with virtually no motion blur.
Panasonic also has a professional reference 4K monitor for broadcasting and cinema production. The model BT-4LH310, priced at $22,995, is a 31-inch monitor suitable for use both in the studio and on location.
The Panasonic BT-4LH310 reference monitor supports both 4K (4096 x 2160) and QFHD (3840 x 2160). In addition to meeting the DCI (P3) color gamut standards, the monitor's new LUT upload function supports high-precision color management in a digital cinema workflow.
The Panasonic monitor features a 10-bit, 31-inch LCD panel that is LED backlit. It will accept 4K sources through SDI, HDMI and DisplayPort. In addition to DCI 4K, it will accept QFHD/UHD 4K (3840 x 2160), 2K and high definition video sources along with up to 16 channels of embedded audio.
For studio wall applications, several companies take large LED/LCD panels, add custom I/O and software, creating full configurable displays. For instance, Evertz makes the MVP Multi-Image Display and Monitoring System. The MVP offers a comprehensive approach to virtual wall monitor applications. It can display any input signal to any output monitor and can used without the need for DAs or upstream monitor routers.
The Evertz MVP system can expand in size from 8 inputs with a single output, to as large as 1000+ inputs feeding more than 50 displays.
The system also integrates monitoring functions into the video wall. Its signal monitoring includes loss of video, active picture levels, EDH errors, frozen or black video, motion detection, video format detection, loss of audio channels, mono audio detection, phase reversal, audio too loud or too quiet, loss of closed captioning, loss of closed cap waveform, loss of program rating, source ID missing and VITC missing.
Other companies making video wall components include Wohler, Orad, Vizrt, VisionFrame, CubeX Video, Marshall Electronics, Planar, Samsung, Vista Systems, Zandar Technologies, Mitsubishi, Barco, Prysm, eyevis, NEC, LG, NanoLumens, Orion, MediaGrid, SiliconCore, EMS, Grass Valley and Imagine Communications.
Control technology for video walls is available from a variety of sources including; Vista Systems, Ross Video, Matrox Graphics, Blackmagic Design, TV One, Gefen, Christie, Seneca, VideoPlex and others.
Remote production trucks can require dozens of video source monitors. Increasingly what used to be a mass of individual monitors is being replaced by several large monitor panels, which can display many sources and yet be quickly reconfigured to a virtually any layout.
NEP, one of the world’s largest studio and remote truck companies, has even launched its own software called The Wall. It’s an app for the Apple iPad that enables quick pre-configuration of complex monitor walls in mobile production units. Monitors need to be reconfigured for each show, often with only hours from the time the mobile unit parks until it goes on-the-air live.
NEP has developed an Apple iPad app that enables the quick reconfiguration of multiple monitor panels. A task which used to take hours can now be done in minutes.
This app allows engineers, technicians and members of a production team to set up their own monitor walls and make changes on the fly whenever they want without having to wait for the mobile unit engineer to go through a long configuration process. Because trucks may have more than 150 individual monitors displaying as many as 32 video sources each, this app can be a huge time saver.
“Compared to our previous manual processes, The Wall was like going from a rotary dial phone to an iPhone 5 overnight,” said Kris Castro, a beta user and technical director for a major sports broadcaster. “A configuration that used to take at least three hours now takes maybe 15 minutes.
“In addition to being a tremendous time-saver, The Wall has given me much more flexibility. Without having to involve an engineer, I can log in to the system and make necessary changes, or configure the monitor wall offline and then save the configurations under my name. If I want to use a configuration from last week, it’s there and ready to load. And if I want to create a layout for a director I’m working with in three weeks, I can do it in advance and then just walk right onto the truck and patch the monitors in a matter of minutes. NEP has created an incredibly smart way of approaching this task.”
Software-based diagnostics and virtual channels on single large LED wall displays have fundamentally changed monitor technology in the studio. However, on original productions for television or cinema, a single high-quality monitor with a pair of “golden eyes” to check quality remains as essential as ever.
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