Implementing 4K in a 3G-SDI Plant: A Conversation With Jean-Baptiste Lorent

Can you use four times the data in your existing facility?
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ALEXANDRIA, VA.—Despite the fact that HD broadcasting is relatively recent, and most people in the U.S. bought their first HDTV only in the past seven years, there is growing pressure to shoot, produce and distribute programming in 4K resolution. There are already a couple episodic TV shows available for viewers in 4K, and more are on the way. Of course, big sporting events will also be shot in 4K, but there are a number of reasons why broadcasters can’t yet deliver 4K to viewers.

One reason has to do with the broadcast infrastructure inside every TV station and network control facility. Although most television broadcast facilities in the U.S. have HD-SDI and 3G-SDI infrastructure that can move signals around at a data rates up to 3 Gbps (which is uncompressed 1080p HD video), the gear can’t go higher than that. And broadcasters, who had to upgrade their plants from SD to HD in the past 15 years, aren’t ready to spend the hundreds of millions of dollars it would take to upgrade yet again to carry the 12 Gbps data streams required for 4K.

Yet the interest in 4K continues and there have been multiple tests showing that it’s possible to transmit 4K in a standard 6 MHz TV channel and still have room for secondary channels. Consumers have been buying TVs with 4K resolution capability, so the elements are starting to fall into place to envision 4K as a broadcast format in the reasonable future.

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Jean-Baptiste Lorent

Still, how do you carry broadcast quality 4K signals in a video facility without tearing everything out and starting from scratch? That scenario is simply out of the question for most broadcasters.

The TICO Alliance thinks it has the answer. It is promoting “non-destructive” compression of 4K that will enable the signal to work in a 3G-SDI plant. The proposal is not a standard yet, but the TICO Alliance is working with international bodies to work out the details and make it palatable to broadcasters.

To learn more about the TICO Alliance, Broadcast Engineering Extra spoke to Jean-Baptiste Lorent, who is the product and marketing manager at intoPIX and leads TICO Alliance’s development and activities. Lorent joined intoPIX in 2007, where he is now responsible for product innovation, marketing strategies and standardization (VSF, SMPTE, EBU) in the broadcast and pro-AV industries.

BE Extra: What is the TICO Alliance? What is it looking to accomplish?

Lorent: TICO alliance is a coalition of companies united to establish TICO lightweight compression in the new IP-based live-production ecosystem. It will allow users to update and upgrade existing SDI-based workflows to 4K/UHD without the cost of a complete renewal.

Launched at NAB Show 2015, the group wants to solve three important challenges to move to 4K and to IP-based workflows with TICO: UHDTV needs more video bandwidth; broadcaster have massively invested in 3G-SDI and don’t want to replace it; and in the transition to IP, 4K has more data than can fit on a 10Gbps Ethernet port.

The group wants to develop and promote technical specifications with different active groups in this transition, such as SMPTE, EBU or VSF, in order to ensure interoperability among TICO equipment. Recently, intoPIX introduced the TICO SMPTE RDD (registered disclosure document) to ensure interoperability to map a UHD/4K stream within a 3G-SDI signal, as well as to map TICO within RTP. These two maps will enable TICO to be used with UHD/4K production workflows that can be IP-based, SDI-based or hybrid SDI/IP.

BE Extra: What is the bit rate of an uncompressed 4K signal? What is the bit rate after it has been encoded using the TICO process? Can that amount of bit-rate reduction really be considered “lossless”?

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Lorent: The table here shows the typical uncompressed UHD data rates vs. the different Ethernet types. TICO compression is typically 4:1, which enable broadcasters to easily support UHD/4K in 3G-SDI 10GbE infrastructures. TICO compression has been designed as an alternative to uncompressed video, with visually lossless quality and no latency.

Preserving quality: TICO compression was studied to be visually lossless with any type of content (not only broadcast videos but also Excel spreadsheets, for example). Mathematically lossless is possible with TICO as it uses a reversible wavelet transform. However at the application level, SDI or IP transmission want to have a guaranteed bitrate, so the TICO rate allocation will guarantee to either add some padding if the content is easy to compress or will activate the rate allocation to reach the expected bitrate. Moreover, another goal of TICO is that it be robust enough to survive multiple encoding generations, which is mandatory for use in production workflows.

No latency: The smallest implementation of TICO has only nine lines of latency in total (six lines at the encoder and three lines at the decoder). Moreover, the latency is fully deterministic (not variable).

Lightweight: TICO compression is conceived as a simple tool to be added on any uncompressed workflow. The inventors have had a strong focus not only on the quality of the compression, but also on the complexity of its implementation which enables existing equipment to be simply upgraded.

4K uncompressed and transmission is unmanageable within current systems and infrastructures. With SDI, 4K needs too many cables (4 x 3G-SDI links) and will require more SDI ports on routers and switchers. An upgrade to 12G-SDI will also cost more than 3G-SDI. Today, 10GbE is the obvious affordable infrastructure solution for intra-plant transport. However, 4K cannot fit in 10GbE Ethernet (11,880 Mbps). Only 4:2:0 goes below 10GbE and higher bandwidth (i.e., 40GbE, 100GbE) ports are too expensive for large-scale adoption. And broadcasters need real 4K 60fps at 4:2:2 or 4:4:4. That’s where the 4:1 compression of TICO plays a role.

BE Extra: What are the audio provisions within TICO processing? For example, does it support simultaneous stereo and surround mixes?

Lorent: The SMPTE RDD of TICO addresses these two questions actually. In the use case of mapping UHD/4K with the active area of 3G-SDI, we do not touch the audio channels that are already transporting with SDI. In the case of RTP mapping, TICO video is transported as an independent payload. Implementers will be following the recommendations made by the SVIP (studio video over IP) workgroup at the VSF organization.

BE Extra: What is the status of TICO with regard to the standardization process? Is SMPTE or any other organization looking into creating a standard that includes the TICO Alliance’s recommendations?

Lorent: The work is done with SMPTE. Currently the Alliance members have been collaborating for the SDI and RTP mapping of TICO, and the work is almost completed. intoPIX will soon submit a first Registered Disclosure Document at SMPTE. TICO Alliance and intoPIX are open to collaborate with industry organizations to standardize TICO and provide recommendations for different applications. Interoperability is an important motivation for all Alliance members.

BE Extra: What else do we need to know about the TICO Alliance and its recommendation for 4K bit-rate reduction?

Lorent: The alliance is growing quite rapidly in a very open and collaborative way. Moving to TICO means less cabling and less cost with more UHD/4K. People interested in this technology should definitely visit IBC2015 and see the different live demos with companies such as Grass Valley, Imagine Communications, Nevion, intoPIX and others.