Contribution and distribution over IP: a transformative change

Jiri Matela, CEO of Comprimato, analyzes in this Tribune how IP connectivity provides new flexibility in both distribution and contribution circuits. JPEG2000 encoding provides high video quality with a 10:1 compression ratio for critical applications where quality cannot be compromised.

There is a lot of talk in the industry right now about IP-based infrastructures. Typically, the discussion focuses on live production and interoperability between systems. This is, of course, extremely important. But there is another area where IP has the potential to create transformative change.

To send content from a remote location to the production center, a contribution circuit (called backhaul in the US) has traditionally been used.

This used to be just that: a single circuit. Therefore, if we covered, for example, a big football match, we would receive a single signal from the mobile unit to the central studios.

Broadcasters deployed permanent circuits from the main contribution places. These were video cables and therefore had no use for any other purpose, which meant that the provider, usually the local telecommunications company, had to charge a considerable sum to cover installation and supply costs.

When video circuits were not available, productions were forced to use line-of-sight microwave links (with limited range and location) or satellite uplinks. Like fixed links, both radio solutions were expensive, risky in terms of vulnerability and, in the case of satellite links, added significant latency.

With the advent of real-time connectivity for professional audio and video, all this has changed. By converting the feed to IP, a dedicated link is no longer necessary and the signal can be transported as data over any carrier with sufficient bandwidth. In particular, as telcos have installed high-capacity dark fiber throughout their territories, and particularly in metropolitan areas that host major sports stadiums, the transmission can be carried as data along with other traffic.

This has meant cost savings since telcos have chosen to charge for the data transported, with broadcasters only paying for what they use. Resiliency has also increased as geographically diverse redundant paths can be used, with the receiving device seamlessly switching between stronger signals.

Múltiples feeds

Successful delivery of the contribution over IP depends on good signal routing and high quality encoding to achieve the best transmission at the most optimal bit rate. Although H.264 encoding has been widely used, and with the emergence of H.265, an ideal application for JPEG2000 is proposed. This codec provides high video quality with a 10:1 compression ratio for contribution applications, and its wavelet algorithms are generally considered to degrade less than the discrete cosine transform used in MPEG-type compression.

JPEG2000 also allows for uncompressed but packaged delivery, where compromises on quality cannot be tolerated.

Once broadcasters accepted the concept of soft compression on contribution circuits, and the IP transport of those transmissions, the obvious question arose: can we carry more than one transmission from the venue to the central studios? This could transform production.

This codec makes possible the ability to deliver multiple parallel feeds of an event. In rugby or soccer, we could have different cuts for each team. For a track and field event, we might have signs oriented to different tracks or fields in a venue. We could have an international source along with a national production that included a feed from an on-site set for debates and presentations.

It also means we can deliver alternative content alongside the main feed, allowing the rights holder to package an event in different ways for different platforms. All of this provides new ways to engage with audiences and monetize event coverage.

Local and remote distribution

Another important requirement is to deliver multiple feeds at the location where an event takes place. An obvious case could be the use of video referee or video assisted refereeing, where the referee could instantly access different camera angles.

Installing a large number of video sources is challenging and time-consuming while working with a single fiber is much simpler.

Although video referee systems are located in the stadium or sports hall itself, over time it is possible that the most important sports will follow the example of the NBA in the United States, which has a centralized video receiver center that collects all the signals from all the games that are held simultaneously.

Broadcasters routinely provide complimentary images to stadium screens and other areas such as the press room or commentary booths. Again, multi-feed distribution over fiber is much easier to implement.

This concept can be transferred to distribution, with the distribution of streams by the broadcaster. Again, this is traditionally a single channel output over a video circuit, which is then modified for the platform at each individual headend. Therefore, the broadcast signal will be compressed by hardware at the terrestrial, cable and satellite headends before multiplexing; and will be transcoded for storage for video on demand and for live streaming across multiple platforms.

This architecture is inherently expensive, as it requires dedicated devices for each flow at each headend. It is also a quality risk, because the transcoders are outside the physical control of the broadcaster, since they are remote.

This same architecture of presenting multiple video streams along one or multiple dark fiber chains can be applied to distribution. This allows the broadcaster or content provider to maintain quality control over all internal encoding, distributing the different required formats properly packaged.

Software coding

Critical to moving these ideas from a theoretical discussion to a practical solution is the ability to encode and transmit large numbers of high-quality lines cost-effectively.

Precisely the strong point of Compressed lies in the implementation of high-quality software-based codecs, to run on standard IT platforms, and particularly on GPUs. This has allowed us to develop the Comprimato Live transcoder, which is a model of how this solution can now be practically delivered.

It runs on any standard x64 server architecture, which can be a physical device or virtualized in a data center. The software supports up to 70 Full HD signals on a single 1U server, making it extremely compact.

All functionality is implemented in software - no additional proprietary hardware required. The software is agile: new signals can be added in less than a minute. It is also easily extensible, allowing new formats such as HDR or 4K to be incorporated instantly as soon as a business strategy is desired.

Finally, it is an independent codec, compatible with MPEG-2, H.264, H.265, Google VP8 and VP9, and JPEG2000. Individual output streams can provide adaptive bit rate delivery as needed.

By adopting this software solution, the Live transcoder delivers high quality at low latency: typically less than 700 ms end-to-end across a video delivery chain. It is also extremely cost effective, eliminating the capital cost of multiple encoders and decoders. Running on industry-standard servers reduces the total cost to a few hundred dollars per stream.

IP connectivity provides new flexibility in both distribution and contribution circuits, allowing producers to create more selective and engaging content, while ensuring that quality is closely controlled as all processing is carried out in-house. Software systems running on standardized hardware benefit from the continuous improvement in performance of the IT hardware industry as well as regular software updates that offer the ability to add new functionality quickly, securely and cost-effectively.