Event Multi-camera Production Challenges & Solutions with NDI
Approximate 10 minute read
Providing multi-camera video production services supporting weekly church services from a recurring location with an integrated AVL system can be challenging. If the AVL system is not permanently installed – as in portable-church applications – the challenges to maintain high production value content and execution increase exponentially.
If then the event is a “one-off,” occurring in a venue nearly 125 years old with little to no permanently integrated AVL infrastructures, the challenge to produce a contemporary concert/teaching event with a “one-day-wonder” schedule (load-in, set-up, rehearse, show, strike, load-out; all in the same day) can be daunting.
This article is about implementing multi-camera video production services staged a venue which has no existing video production infrastructure. The example venue is from the late nineteenth century and besides offering electrical power tie-in, has very few facilities for implementing a contemporary concert.
This creates a unique opportunity to transform a 19th century venue into a 21st century concert experience. My church (Calvary Chapel Old Bridge) and its radio station (Bridge FM), have an annual outreach event in Ocean Grove, New Jersey called Bridgefest, a multi-venue event offering adult and youth teaching services, a surf clinic, an ocean baptism and a concert featuring (this year) performances by The Afters, Citizens & Saints, Jonny Diaz; and a message by Pastor Tony Clark of Calvary Chapel Newport News (CCNN) in Virginia.
The concert event is held in the Great Auditorium, which currently seats about 6,000 people (originally designed to hold 10,000) and completed in 1894. Modern events require all of the equipment to be brought into the venue, including lighting, sound, projection and video production services. This article provides some insight into challenges and solutions for implementing video production for this event.
There were four fundamental parts of the event as it relates to video production. These were the “walk-in”, live music, teaching and recorded video clip play-out.
The walk-in starts when the doors open to the attendees and it lasts for about an hour. The design goal is to provide information about the radio station and the sponsors of the event. For the live music portion the goal is to provide image magnification (IMAG) of the musicians on stage as well as to provide a method for either lyrics or visual media to be presented while the bands are playing. During the teaching portion video projection provides image magnification and lower-third graphics. Finally, pre-recorded video play-out is simply playing videos to the projection screen with its associated audio.
The “walk-in” was the part of the event that had both the most flexibility as well as an opportunity to utilize many features of the TriCaster. What has been displayed during “walk-in” has changed over the years. For example, the radio station has six different frequencies and call-letters, depending on which geographic region the listener is in. The radio station also has a website, which has an Internet address to be promoted. Each of these frequencies and the website address is visually implemented as an animated graphic or “bug”. Each bug starts from the extreme left off-screen, moves towards the right on-screen as it builds to complete the image. After a few seconds the completed graphic fades and a new animated bug appears. There is also a static graphic bug on the right-hand side of the screen with the name of the event.
Each bug was implemented in an animation buffer. There are ten of these available in the TriCaster 8000 AE production switcher.
Each animated bug is created in Adobe After-Effects and exported as an (H.264) MP4 video with an Alpha channel. Each movie file is then loaded into a TriCaster tool called Animation Store creator, which takes small video files and creates an output that can be loaded into the TriCaster’s animation buffer. Animation Store creator preserves the Alpha channel, which allows animated graphics to be keyed on top of a live video with high quality. This is generally accomplished in a production switcher with a down-stream key (DSK), which is mapped to a specific animation buffer. The TriCaster 8000 AE has four downstream keys on the main bus, four downstream keys on each ME (Mix Effects bus) and four upstream keys on each ME. That is a lot of keys! However, the problem is not having enough keys, but having enough hands to implement the keys.
The walk-in video layout also had two active video sources, one being a loop of about 60 static image slides and the second is live video from any one of three video cameras we were using. As the technical director, I needed to be able to loop the various animated “bugs” as well as switch cameras for walk-in projection of attendee “candids”. It is possible to manually loop the bugs using a couple of the down-stream keys, but that is really not a practical solution.
Here is an example of the static and animated bugs over a motion background:
The TriCaster has macros which can provide automation to the operator workload problem, but I chose instead to use the remote-control SDK as a solution. The remote-control SDK allows me to have a software program automatically change the animated bug on a periodic basis. This program was running on a laptop which connected to the TriCaster via Ethernet. Since changing the animated bugs was now automated, this allowed me to focus on switching the camera shots.
Another important element on these events are lower-third lyrics and titles. Our lower-third graphics were generated by a computer running ProPresenter 6 software. The connection from graphics computer to the TriCaster was accomplished using NDI.
NDI is an IP based real-time video protocol developed by NewTek. This connection allows the graphics computer to appear as an input source on the TriCaster via an Ethernet connection. Once connected, both NDI and SDI sources can be selected by the production’s Technical Director. Full screen outputs from the graphics computer don’t require any special attention, however lower-thirds assume that there is an alpha-channel, allowing the graphic output to appear keyed cleanly on-top of the live video. Both NDI and alpha-channel capabilities are available from ProPresenter, but the cost for the alpha-channel option is often cost-prohibitive just for a single day church-sponsored non-commercial outreach event. For previous Bridgefests the alpha-channel license was transferred to the on-site event computer from another computer at the church. This solution was acceptable since the event happened on Friday and there were no church services Saturday. However, this year Bridgefest occurred on Saturday and there was church services on Sunday, making any transferring of licenses and computers a potential risk.
The TriCaster can chroma-key any input source. This allows the Technical Director an alternative solution to keying images versus alpha-channel.
Most recently the Bridgefest event provided an opportunity to experiment with some new gear and features of the TriCaster. The new product is called the Newtek Connect Spark, and it provides live wireless video via WiFi and NDI|hx. The Spark also provides tally light functions to the camera operator, with both on-air red as well as a green preview indicators. There are two versions of the device subject to the input format of the source video signal, HDMI and SDI.
We tested Spark using a Nikon D810 DSLR and the Connect Spark HDMI. The Nikon D810 will output full HD 1080p at 29.97 frames per second. The Connect Spark was attached to the D810’s flash hot-shoe and connected via the HDMI output port on the camera. Using a consumer grade WiFi solution we saw about a second delay in the video, so not every type of shot could be taken using this wireless solution due to latency. It is important to note that the excessive latency was not caused by the Tricaster switcher itself, but was instead inherent in the WiFi / Spark solution.
One of the biggest challenges noted was ensuring the WiFi network access points were in close proximity to the camera. Our experiment used a single consumer grade WiFi solution which didn’t provide the signal range required. Our next experiment will be to utilize enterprise grade access points, wired through-out the venue. The back-haul for each access point will be using CAT5 cable, aggregated onto an enterprise grade Ethernet switch. Each access point will have a dedicated one gigabit connection to the switch. The TriCaster will then be connected via one gigabit Ethernet to the switch which should reduce the excessive latency and improve the range of our Connect Spark device.
The recorded video play-out, combined with the requirement to record audio/video portions of the event, created some interesting challenges. At a previous Bridgefest event the TriCaster was being used both as a DDR video clip playback device and as our video recorder, and we accidently caused a feed-back signal loop between the PA system audio console and the Tricaster. Having learned a lesson, this year the problem was solved by implementing four connections to the PA system (two dedicated inputs, two dedicated outputs) ensuring the Tricaster internal DDR used for video clip play-out was the only audio source routed to the inputs of the PA audio console. This worked well and did not require muting/unmuting channels on the Tricaster during the clip playback.
When preparing for a live one-day-wonder event outside of a modern venue complete with integrated AVL facilities, the following list are items one may want to consider:
Testing power with a volt-meter at each point where video gear will be plugged in may help prevent hum-bars in the video signal (and audible hum in the sound). If the venue has an electrician, ideally the house electrician would test the power before allowing you to plug-in. However even when doing a show in venues with an electrician, often house electricians don’t test the power daily, or before each show. Therefore it is up to the visiting AVL technician to perform rudimentary tests before plugging in and powering up. Since you may not know if the house electrician has tested the power, it’s always advisable to test the power before plugging in.
If the power distribution is single phase, or three-phase broken out to multiple legs of 120v services (and in the United States) checking voltage with a volt-meter across hot and neutral of the 120v (or single leg) service should read between 110-120 volts. If the reading is a few volts higher or lower that may be fine. If the voltage exceeds 125v or falls below 105v you should advise the electrician or venue manager as it may indicate a power related problem.
One should then check the voltages between hot-to-ground, which should have an identical reading as hot-to-neutral. A third test is checking voltage between neutral-to-ground. A volt or two difference between the hot-to-neutral and hot-to-ground readings, or a volt or two read on a neutral-to-ground reading may be normal for some venues. Higher voltages between neutral-to-ground indicate a power related problem warranting informing the house electrician or venue manager.
If the venue’s power distribution which you will be plugging into is single phase, make sure you know what your power draw is at each connection point insuring you do not exceed the circuit breaker or waber strip amperage rating of each circuit and strip. If the venue’s power distribution is three phase, keep in mind the recommendations made for single phase and insure that the amperage draw for all AVL equipment (video and other tech departments) is equally distributed across the three phases. If the total AVL system amperage draw is substantially higher on one leg than others, power related issues may ensue.
Control Room Location:
Consider where you will locate your control room (or “video village”). There are advantages and disadvantages to most locations including accessibility to audio feeds, proximity to projectors, cable paths for cameras and audience safety if near cables. Consider how noisy your production staff may be during show and the potential distractions to audience members. Also consider potential seat kills and fire aisle clearances if putting the control room position in the house. For Bridgefest our video village was in the house near the FOH mix position consolidating most tech departments into one area of the venue.
Having a trustworthy communication system for the Director, Technical Director, Graphics person and Camera operators is invaluable. Also consider the potential need for Stage Manager(s) or Stagehand comms. It is usually a good idea to give the projectionist, PA audio team and lighting team some way to communicate with the video team if/as necessary. If the event is a concert, some crew positions may require (“Dave Clark” style) high noise headsets. For Bridgefest we rented a two-channel hardwired RTS system.
Tally & Shading:
In previous years we shot the concert and teaching with three cameras; one back of house, one from a side angle, and one handheld; without tally and live shading control. Cameras were auto white balanced before the show and iris settings were called out on the fly over headsets. As a result, the Director or TD would have to take time out to discuss setting with the camera operators, “camera #3, open one stop,” “camera #1, stop down,” “camera #1, down a bit more,” “camera #2 you are live,” “camera #2 clear.” Because of this, the pacing on the line-cut was slowed. If you have many cameras you can maintain a fast pace while making technical adjustments. You have more choices. But when you only have two or three cameras, calling out technical adjustments takes time away which could otherwise be spent improving the esthetics of the visual product. This year we added a rudimentary shading position (three RCP panels and a decent HD monitor) and connected tally lights to the cameras. As a result, we were able to concentrate more time on making better artistic choices, quicker, than discussing engineering settings.
Planning cable routes and distances is also important. There is nothing worse than building cameras or a control room only to discover you do not have enough camera, video, audio or comms cable to span the necessary distances. Equally bad is finding out you are beyond the distance HDMI, VGA or SDI can travel on the type of cable on hand. For Bridgefest the rented cameras that operated on SMPTE camera fiber allowing very long distances, comms and power all on one cable. Projectors and band lyric computers (about 300’ away backstage) were connected to video village via a TAC12 single-mode ST fiber run and fiber-modems, standardizing everything (except for NDI sources) as 1.5 gbps HD-SDI.
Schedule & Labor:
It’s important to plan an ample production schedule back-timing into when the artists or other departments need cameras up and functional by. In general, it is advisable to figure out when sound checks or rehearsals will occur, and then back-time in the amount of time load-in, set-up and meals may take. Depending on the number of skilled and unskilled people are available to assist and the distance of cable runs, a rule of thumb is one hour for load-in, four hours for set-up, one hour for security sweeps and one hour for meals. That means if the first sound-check/rehearsal is at 3PM, video will likely need to load-in around 8AM. Add onto the 3PM rehearsal the time needed for all sound-checks/rehearsals to be complete, another meal break, doors open/audience walk-in, the event itself and a strike/load-out, and you can estimate a likely out-time. In general, one-day-wonder events can often involve a sixteen-to twenty hour work day.
Make sure the crew knows when and how long their services are required. When working with volunteers at a one-off one-time event, unless explicitly told they are needed for the strike and load-out some volunteer crew members may go home with their families after the event has ended potentially leaving you short-handed for the strike and load-out. Proper communication and planning will avoid this problem.
Food & Snacks:
Napoleon is credited with the saying that what a soldier needs most is, “A full belly and a good pair of shoes.” In a similar way, an AVL crew will work best when there is ample water, soft drinks, juices, coffee, fruit and healthy snacks (breakfast & protein bars, peanut butter, etc.) available. Food that can stay out and not spoil after many hours is important, as is variety. Avoid bags of popcorn, potato chips and similar junk food which not only slows a crew down but can easily make a mess in the venue. Also avoid large bowls of shared open-air “community” food. Crew members get dirty and community foods can lead to someone getting sick during the show.
There are many things to consider when implementing video production for an event outside of one’s normal venue. One of the most useful considerations is equipment that can perform many different video production functions. This allows the video technical team to have more than one option available to solve challenges that are part of event video production. There are many features of the NewTek TriCaster which allow flexibility in implementing technical challenges. A key aspect of this article is to look for gear that allows the video technical team to be agile in implementing evolving requirements at an event. I hope that this example will help you in implementing your next off-site live event production.
William R. Beckett is the CTO at Right Angle Research. Recently William served as Senior Research Director at NBCUniversal MediaLabs. His focus was designing and implementing solutions for automating media creation using machine learning techniques. Prior to joining NBCU he worked for AT&T Labs Research. In that role he designed and implemented solutions for mobile network operations, DDoS defense, secure electronic payments, digital rights management, financial reporting and customer care. He holds an MS in Computer Information Systems from Boston University and has been granted 7 patents.