TORINO, ITALY: Even though the outward appearance of the rooms in NBC's 75,000-square-foot Torino facility was the same as at prior Games, it was obvious this Olympic broadcast effort was different than any that have come before.
Signs reminded the busy crew of the day and date, or how many days remained till the next opening ceremony in Beijing. Such signs are common on the walls of Olympic broadcast facilities, but in NBC's broadcast facility in Torino (also known as the "IBC"), these low-key, often humorous postings were joined by some a bit more serious.
One, headlined "HD ain't the same as SD," was taped on the facility's narrow walls in at least a dozen places. It reminded the 2,850-strong crew of the simple fact that "everything is DIFFERENT," and that HD should not be minimized or taken lightly. Also evident on numerous doors and walls was a diagram of what was known as the "Aspect Ratio Roadmap," a here-to-there representation of the six possible ways to get from one format to another in a world that involved 16:9 SD, 1080i HD in 50 or 60 Hz, 4:3 SD and more.
Doing an HD Olympics--indeed, managing what was for 17 days the largest HD facility in the world--was clearly a tough, unprecedented job for NBC's Olympics team.
"The most gratifying thing is the fact that we took an incredibly complex event that had a very high standard developed over several Games, and we pretty much turned it upside down on the inside," said David Mazza, senior vice president of engineering for NBC Olympics. "And what came out of all that is we are at about 85 to 90 percent of the functionality we were at with SD in terms of what we could deliver to our customers, the production staff."
"Turning it upside down on the inside" meant that NBC, its broadcast partner Sony, and systems integrator Ascent Media spent 15 months or so between Athens and Torino "overlaying" an HD layer on top of and around the legacy SD NBC Olympics infrastructure, an infrastructure that had been traveling the world on shock-mounted racks-in-a-box (RIBs) since Sydney. In Torino, a new 256 x 256 Sony HDSX-5800 router running at an impressive 1.5 Gbps was at the heart of the conversion. The "old" 270 Mbps SDI router handled some audio distribution, much of the monitoring, and some transmission.
All editing and production in NBC's IBC was in HD, with the exception of curling coverage. All switching in the facility was in HD, even though the Sony MVS-8000a switchers in NBC's control rooms were capable of either HD or SD operation. And although NBC's camera workhorse--the recently debuted 14-bit Sony HDC-1500s--were capable of outputting an SD signal, they stayed HD too. The SD signals seen in the US on NBC and its cable entities were downconverted from HD.
NO HD FLIPPING
"Probably the best decision we made in terms of the conversion was to decide to not try to flip the control rooms and the tape rooms and the edit rooms back and forth between HD and SD," Mazza said. "We could have done that--the cameras, the switchers, the EVSs, they all could switch back and forth."
Mazza said that when the team thought about it, the worst thing that could happen when doing an SD show in an HD control room would be that the signal took a trip up to HD that it didn't have to. With about 75 percent of sources in HD, producing in HD and downconverting as needed saved a lot of trouble. There just wasn't an "upside" to downshifting control rooms to SD or flipping all the monitors.
"Yes, we did move a lot of 4:3 pictures though the control rooms that were going to, say, USA Network, and only airing there in SD," Mazza said. "For example curling came through here occasionally in 4:3 and they happily watched it in the control room as pillar-boxed, knowing that the sides were going to get cut off for their show."
Mazza said that keeping the plant consistent saved them a lot of headaches. Staffers didn't have to think about whether they were recording SD or HD, which would have required different tape machines or a different configuration on a server.
"By standardizing on HD and up-rezzing everything when it first came into the plant--even the 4:3 curling got up-rezzed to HD and archive material got up-rezzed when played into an editor--it made life for the production people far easier than trying to deal with HD and SD as a recording format," he said.
But doing an HD broadcast on this scale at this still-early stage of the technology was not easy. Regarding the day-to-day challenges of getting the first true HD Olympics broadcast done, Mazza said that his biggest concern going into the Games was the aspect ratio issue--how to make sure the crew grasped issues such as anamorphic versus letterboxing, and how to make sure the crew knew how to convert source material in a variety of formats into needed final products.
Mazza was pleasantly surprised that aspect ratio ended up being a complex but manageable issue.
"We had a lot of conversion options but we zeroed in on the ones that we thought would be most effective," he said. "I would say the upconverters and the downconverters in the [Sony HDCAM] tape machines were crucial. The fact that the Avids could mix HD and SD on the timeline was also critical, but it was the tape machine that became the savior on that--it was sort of the rubber band that would play anything to anything."
Less manageable were some of the issues involved with other bits of the HD production or transmission chain, chains that are admittedly not as far along in terms of interoperability as their SD brethren.
"In all candor I think the discoveries that were made here regarding HD were better made here than in Beijing, and HD vendors just have more work to do," said Matt Adams, director of technology for NBC Olympics. "To their credit, the vendors that were helping us at the Olympics stepped up and learned and made some incredibly fast fixes to help us out."
What kind of problems still exist in the HD world? Adams said one major problem is the slow evolution of HD standards conversion.
"The fundamentals of the problem are that the state of the art in HD standards conversion creates unusual artifacts--the simple way to think about it is, we were native 1080i 50 Hz 25 frames and we wanted to broadcast 1080i 30 frames, so we basically had to create five frames out of thin air, " he said.
When coupled with the aggressive nature of ATSC compression, this led to artifacts at the final terrestrial receive point.
"We can't really change this. We can manage it--you can do tricks, but there are a variety of encoders at TV stations all across the U.S.," he said.
Adams said that standards converters, in order to accomplish the worst-case scenario of creating five frames, create non-redundant images. This doesn't work well with the ATSC's long-GOP structure, which relies on only sending the differences between frames.
Adams said that the beginnings of HD in Europe will likely generate some momentum on the issue, which could be "fixed" by next-gen converters capable of passing metadata along to the encoders.
"There is a generation [of converters] that is expected to be around in time for the June World Cup in Germany," Adams said, referencing another event involving 50 to 60 Hz HD conversion. "I'm sure at NAB, you'll see some manufacturers that will have some tricks to be more long-GOP friendly."
Not all of the HD challenges were big issues. Mazza said a host of small issues consistently popped up.
"It was the interconnected equipment when you got two, three four, five, six things in a path... sometimes the first thing in the path was driving the last thing in the path--which might be on another continent--crazy. We chased that kind of issue from beginning to end, every day. Fortunately it was small things mostly not visible or imperceptible on air," he said.
The HD challenge was also evident at the venues, said Chip Adams, director of venue engineering for NBC Olympics. One example was getting HD split signals into mobile units.
"Right now, the longest you can go with cabling is about 500 feet, and at large events like this your truck is parked maybe 700 feet away and the truck you are getting the signal from is perhaps 500 feet away," he said. "Because we get signals that have to go to a technical operations center first, where they typically get barreled, they don't go into reclocking DAs necessarily before they get fed out to us."
Adams said NBC put in a lot of reclocking DAs to take care of that issue, but that's a good booster for only about 500 feet.
Another big complicating factor was the lack of a production HD standard for compression that works across multiple platforms.
"All the vendors have their own compression, and as long as they all stay in those positions the industry is not going to move forward," Mazza said. "I would challenge Avid, EVS, Sony, Grass Valley, Leitch and everybody to work together to arrive at several different quality levels of similar HD compression that each platform can read, record, ingest and play-out."
HD just isn't there yet in terms of being as user-friendly as SD, Mazza said. "I realize it's a timing thing and people need to get their products out the door, but we've moved backwards about three steps on workflow in HD... we're still moving baseband video from an EVS to an Avid and that's crazy in this day and age."
During the Olympics, NBC actually facilitated a meeting between Avid and EVS to encourage greater compatibility in file formats.
"We can't go too much farther with our workflow until there's a common HD compression standard," Matt Adams said. "It was a big time saver for the production people to make a clip list and then give an Avid Adrenaline control of an EVS channel--[which] would then suck the clips right in to the Avid as baseband--but this should really just be a file transfer."
Beyond the fundamentals of the HD plant and the early nature of the technology, NBC successfully deployed a lot of other genuinely new technologies and techniques in Torino. More equipment than usual got its baptism of fire at the Games, almost always of necessity.
HIGH-DEF RF, HDV DEBUT
One very new technology that worked very well was the use of high-definition RF cameras from Link Research, which NBC had only first tested in December, according to Chip Adams. NBC was ahead of the host broadcaster on this score, as TOBO was still using SD in wireless applications.
"It's an HD RF camera with pretty short latency, around two frames," said Chip Adams. "This was the first time this had been done at an Olympics, and we had four of them going all at the same venue with three on adjacent channels. It worked very well."
The Link HD RF units were used with Sony HDC-1500 cameras and a paint system from Total RF. The HD SDI camera output was received in the venue, at the RF receive location, and then sent back to the trucks via an HD fiber-optic transmission system.
NBC was pleasantly surprised at how well the cameras worked, said Dave Peters, RF project manager for Total RF, on-site with NBC for the Games. "The RF from the cameras worked extremely well, similar to in SD," Peters said.
RF CAMERA PROGRESS
The lack of an HD RF camera had been one of the obvious gaps in HD production. Has the gap been closed? "It's close... it's really good but it can be better," Peters said. "It can be better with a higher data rate."
Peters said the cameras worked fine for interviews, but the images suffered a bit if the cameras tried to track high-speed action. He said Link already was working on firmware that would increase the data rate to about 35 Mbps, to better handle higher motion capture.
Beyond wired and wireless HDC-1500s at venues, NBC used a mix of HDCAM and HDV camcorders for ENG-style shooting. This was an Olympics debut for the latter, and the little cameras worked well as second cameras for multiple camera ENG shoots. NBC experimented with the less expensive units in the hopes of deploying more of these cameras in Beijing.
All of NBC's lenses were provided by Canon, from 100x units at some venues, to studio lenses to ENG style glass. Canon provided full on-site support for those lenses and also those deployed by other broadcasters.
The proxy-based workflow gains initiated at the Salt Lake City Olympics and accelerated in Athens continued in Torino.
The archive and production system, a custom configuration of Blue Order's Media Archive controlled by Cyradis software and connected to NBC's legacy Olympic archive, came into its own in Torino. NBC news and sports clients logged heavy use, according to Peter Humphrey of MAM consulting specialist Media Strategy Partners LLC, who helped NBC on site with the system.
"Blue Order was very much chugging forward," Matt Adams said. "The driving force of this whole effort was a content access effort and now we have very much achieved the goal of making all content captured available to anybody in our facility on a PC."
The system in Athens saw MXF wrapped MPEG-4 proxies generated by Sony MPEG IMX e-VTRs. In Torino's HD environment, ingest was necessarily handled by Sony HDCAM VTRs, which can't make proxies. A Portuguese company called MOG Solutions provided MXF proxy encoders to fill that gap. Also new in Torino was the incorporation of time-stamped real-time statistics metadata into the software.
The next hurdle for Beijing is to extend the system to a LAN solution, which means working with long-distance high-speed data pipes.
"We had some good experiments here that were successful, but we do not yet have a finished LAN solution for the China distances," Adams said.
In a similar vein to the Blue Order system, EVS' new IP Director software found a place in Torino as well, providing a viewing port for what was on the EVS servers for production people.
"The IP Director gave anybody with about 10 minutes of training the ability to look at what's on the servers, easily log what's on the servers, look for shots and then play them out to the Avid," said Greg Macchia, general manager of operations for EVS , who was on site throughout the games. "It was now very easy for anyone to walk up to an IP Director and pull something out of the server."
"It was aggressively used and successfully used to do for the server side [of ingest] what the Blue Order was doing for the tape side," Adams said. And unlike the tape side of ingest, which can only call up proxy video before the ingest is complete, IP Director allowed access to even the full-res clips during ingest.
MORE SERVERS
Servers--in this case roughly 50 EVS HD XT[2] servers along with a few SD units--were deployed at the IBC and venues. Although the Torino library was still tape-based, that was purely for production purposes. In Torino servers took over a large amount of the capture and all playout was server-based.
Beyond the IP Director, two other new features in the EVS servers simplified NBC's quick-turnaround editing. One was in the playlist, where a function called "replace" was similar to doing a matchframe edit. Another function accomplished the equivalent of an audio- or a video-only edit on the timelines.
Mazza said he was looking forward to the day when NBC could use servers more fully on its record wall, but this can't really happen till vendors agree on an HD production standard for compression that works across multiple platforms.
One ubiquitous use of IP-based technologies was in communications. NBC deployed Telex' new RVON (RTS Voice Over Internet Protocol) system for the first time at an Olympics. (See "Comms Go IP at Torino," p. 30).
Beyond the comms application, IP crept into more applications than at any prior Olympics, in a variety of devices including about two-thirds of NBC's telephones. All sorts of other IP packets were flowing across data lines, including some video, camera control, router control and audio control.
"It worked great and helped us out a lot," Chip Adams said. "For example, normally at a venue like 'daily medals,' we would have had to have a small truck or facility there that would take our four cameras and the host feed, and cut it with an audio board and then send it back on a single transmission line to the IBC."
But in Torino, NBC took the three venue cameras and the host feed, put them into Tandberg encoders, and fed the output back to a control room in the IBC where the coverage was produced.
"In this way we're thinking of using facilities that aren't utilized 100 percent during the Games, " Adams said. "It was an experiment to see how well it worked, what were the difficulties."
Around the middle of the Games, NBC even started moving IP video over the circuits used by its "edit-at-home" experiment which involved U.S.-based editing supporting the effort, (see "Staying Stateside to Edit Olympics," p. 22).
"We realized we needed to get some video home on that circuit, which was already configured for IP," Mazza said. "It had no slice out of the bandwidth for anything other than IP, so we asked Tandberg for an IP video card to packetize the video."
