NBCUniversal Operations & Technology Delivers Tokyo Olympics to Viewers in 4K HDR, Dolby Atmos

NBCUniversal Operations & Technology Delivers Tokyo Olympics to Viewers in 4K HDR, Dolby Atmos Complex workflow promises a brilliant future for video and audio quality By Jason Dachman, Chief Editor

Friday, August 6, 2021 - 2:51 pm

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NBCUniversal efforts in 4K HDR video and Dolby Atmos audio date to the Rio 2016 Olympics, but the Tokyo Games mark the widest distribution - by far - of live 4K HDR Olympics content to U.S. viewers. Although NBC's production model to create this content in Tokyo represents a giant leap forward in the evolution of live 4K HDR and Dolby Atmos production, the transmission and distribution scheme necessary to maintain video and audio quality all the way to viewers' homes has been equally groundbreaking.

For the first time, NBC's Opening Ceremony and Olympics primetime shows are available live via localized 4K HDR simulcasts with Dolby Atmos audio. In partnership with NBC affiliate stations, NBCU Operations & Technology (O&T) has rolled out a solution to enable local 4K HDR simulcasts with local commercial insertion in the top 52 markets - a first for a domestic broadcast network.

We're very proud to have gotten to this point, says Dotan Johnson, VP, on-air operations, NBCU O&T, and we are delighted to be able to deliver the Olympics in live 4K HDR for our NBC audiences.

Inside NBCU's Single-Stream' HDR Live Production NBC has created a single-stream HDR live production workflow that enables production with the highest possible quality for both HDR and HD SDR audiences. NBC Sports produces live 1080p HDR productions in Tokyo and backhauls this live content to the NBCU O&T Network Operations Center (NOC) in Englewood Cliffs, NJ, for distribution to U.S. homes.

Part of the the NBCU team that led the charge in creating the 4K HDR Dolby Atmos distribution workflow for the Tokyo Olympics: (front row, from left) Jim Starzynski, John Rose; (back row) Chris Seeger, Ryan Forrester, Brian Duffy, Anil Abraham

The feeds are backhauled via AT&T fiber circuits and arrive at the facility as 1080p HLG using Media Links J2K encoders. The feeds are converted to PQ (perceptual quantizer) and 4K resolution to match NBCU's distribution standard. All HDR conversions are performed through a series of NBCU-optimized LUTs (look-up tables).

We were able to develop what we call our single-stream UHD HDR recommendations by fine-tuning all the conversions. In collaboration with Cromorama to develop LUTs, we preserve the original artistic intent - the colors, light, and white levels - in a consistent manner, says Chris Seeger, director, advanced content production technology, NBCU O&T. Converting the feed from HLG to PQ, he adds, preserves the capabilities of linear production, which currently occurs at a peak of 1,000 nits. PQ enables both content types (SDR and HDR) to be displayed on the same live linear channel without changing the original artistic intent.

NBCU has chosen PQ as their linear-distribution standard and conforms all remote contribution to this format to simplify distribution workflows. The broadcaster has also standardized on PQ as its live-emission format, which is also the most common HDR format for streaming devices/services.

4K HDR Distribution to Affiliates With Local Commercial Insertion During primetime, output for a 4K HDR channel is encoded into an HEVC, mezzanine contribution stream by Harmonic's XOS Advanced Media Processor. This stream is sent to NBC TV stations in the top 52 markets using Techex MWEdge, which interoperates with NBCU-developed software (Motiv) installed at the affiliate using open-source SRT protocol over managed fiber connectivity made possible by Comcast Business. Mike Harrell, VP, distribution engineering, NBCU O&T, notes that each affiliate is interconnected to our next-generation backbone, built on top of Comcast's nation-wide optical backbone also provided by Comcast Business.

At each station, Harmonic's XOS system receives the mezzanine HEVC feed, inserts local commercials and outputs an adaptive-bitrate (ABR) ladder with the top rendition at 18 Mbps.

What we're doing here is maintaining the highest possible quality throughout the entire chain, says Anil Abraham, senior director, architecture and engineering, NBCU O&T. We don't ever want to see a big shift downward in quality as you get to the end of the chain. From the onset of this project, our goal has been to maintain that experience for the end viewer as if they were standing in Tokyo watching the live feed [at the IBC].

What we're trying to do for our distributors is offer something that they can provide all the way to the home without re-encoding, he continues. Leaving our plant [is] a ready-for-consumer encoded stream that can be passed directly to the consumer with the same pristine quality.

In addition to the NBC primetime channel, NBCU O&T created Golf Channel and Olympics Channel 4K HDR channels to distribute 4K HDR golf, tennis and wrestling competitions nationally to partners.

Immersive Audio to the Home With Dolby Atmos The transmission chain for audio is equally complex for delivering Dolby Atmos to U.S. viewers with capable sound systems. First, the feed is sent from Tokyo as JPEG2000 with 10 channels of uncompressed PCM audio. In Englewood Cliffs, it's encoded to Dolby AC-4 - marking the first time AC-4 is being used for pure mezzanine distribution, according to Jim Starzynski, director/principal audio engineer, NBCUniversal. From there, the audio stream is sent along to the Harmonic XOS encoder at Englewood Cliffs and ultimately converted to Dolby Digital Plus JOC (Dolby Digital Plus with Dolby Atmos overhead-speaker content) for release by affiliates.

Our main goal was to establish a straight, clean piece of wire from NBC to our stations, says Starzynski. AC4

LINK:	https://www.sportsvideo.org/blogs/?blog=tokyo-olympics&news=nbcunivers...
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