Transformation to HD
By Asier Anitua, Business Development Manager EMEA & LATAM at Telefónica Servicios Audiovisuales
With the advent of DTT, it was clear that SD was the standard for “tube resolution” (4: 3). Very soon afterwards, the HD and 16: 9 broadcast tests began and many stations began to deliver their TV offerings in HD, at least in the broadcast part, not so much in the production part.
Regarding 4K broadcast, we should look towards the future with hope since it is a format that has come to stay, but if we look at the past it will give us the keys as to when we will be able to enjoy general 4K stations natively. The key to accelerating the implementation of 4K technology is given by the large platforms and the use of the internet as a broadcast medium, with Smart TV sets and apps providing viewers with ultra-high definition TV, usually on demand.
There are already several stations that have made experimental broadcasts in 8K resolution. This resolution is seen as the ceiling of what the human eye can perceive, as more quality in resolution would he hardly noticeable, but subjective quality is not only about resolution.
Thinking of HD -High Definition- means above all thinking of 16: 9. Therefore, if the leap from SD to a higher definition should be gradual, the first thing we must do is convert all the equipment into 16: 9, starting with cameras and not leaving out any element that requires a change from 4: 3 to 16: 9 signal processing.
Broadcasting in HD is not the same as having a full native HD stream, from capture to broadcast. In the UK there are still many TV stations showing the HD logo in their broadcast that actually produce all content in SD and then scale it up in the last stage.
For transforming a TV channel, short, medium and long-term plans are required. On many occasions the day-to-day absorbs everything and immediate need takes precedence over the ideal, workarounds are put in place just to get going and a contingencies force to leave aside any proper actions that would be contemplated in a well thought out-out master plan.
One of the first actions being sought in this transformation is to convert everything to digital, that is, streamline all workflows and if there is any linear component, be it capture, recording or editing equipment, transform them to non-linear. We seek efficiency through a tapeless solution. This naturally includes old video magnetic tape files and their conversion to digital, so that they can be used optimally and efficiently.
Sometimes we find streams of linear editing in the press, mixed with the latest in non-linear technology in programs along with disconnected areas of interactive make it through the best they can. ENG cameras of multiple formats and brands for the same television program, some SD, others HD, some P2, others XDCAM and some Prores. Faced with this, the first thing is to sort out, unify and simplify, avoid mixing formats and strive for standardization. This search for simplicity makes production volumes increase, making processes more simple. If we think of a TV station as a factory of audiovisual content, we must apply the same parameters that we would apply to any other factory, but considering also the very important creative part of talents, artists, operators and filmmakers.
Does it make sense today to move from SD to HD or should we already consider 4K or at least HDR?
The answer, as it usually is: It depends, not all televisions are the same, nor do OTT platforms have the same requirements. Therefore, the values to be analyzed are, for example, what budget we have, what use the channel has, where it is mainly broadcast, how it is broadcast, how often a technological renovation is carried out, etc.
In some countries there is a tendency to amortize equipment in five years, which later become seven and end up as ten or even a longer lifespan; this is logically a factor to take into account. If our experience is that we usually change systems every many years, we must think of a new system that can withstand the test of time well and leave the door open to migration to new formats, as this would otherwise condemn us to work in lower qualities than those used by potential competitor, which detracts from our company.
Manufacturers have seen this dilemma clearly and offer hybrid solutions and equipment capable of working in HD and, optionally, in 4K. The business model of upgrading under a license and even temporarily, is booming. Likewise, we see that more and more technology renewal specification sheets as a service are becoming increasingly popular, as this allows changing systems and improving quality at the end of the contract.
On a small channel, a local television that broadcasts on DTT for instance, although most viewers use an OTT app or even 4K YouTube. Here, Black Magic equipment in 4K is a viable alternative, given that the budget is low, the highest possible quality is required in resolution and the workflows and content are small and simple. Although this quality does not reach the TV broadcast grade, nor for certain platforms, it is one more option currently available on the market.
A medium-sized channel, with a higher budget and more viewers, requires more professional and broadcast equipment that ensures better quality, support and adequate maintenance, so the budget rises and 4K can be more inaccessible, even more so if the broadcast is in DTT and the content does not require quality higher than HD. In this case, we would stick with HD for the next few years. At this point, the recommendation would be, -as much as possible- to acquire the most critical equipment in 4K compatibility.
But on a television channel or platform producing very high-quality content, first-rate television series, sports that are watched all over the world, high definition and even HDR can fall short, and moving to 4K definition is a must.
Let’s say that producing in 4K, nowadays, can be something acceptable when referring to cameras and editing systems, but things get more complicated when it comes to production systems for news programs, file systems, shared storage, etc.
The big leap in quality from HD to 4K or even 8K in production requires transforming all traditionally HDSDI signals into IP, under the current SMPTE 2110 protocol. Today’s digital transformation is no longer just going to HD in coaxial, it means making the switch to IP technology under standards that unify and simplify the interoperability of the different brands and manufacturers.
Just as the beginning of the MXF was somewhat complicated and painstaking, we are on that same path with the SMPTE standards, with the 2110 being the clear winner nowadays.
Regarding the technical area, how should a digital transformation to HD or higher-resolution formats be approached?
Critical points in a broadcast infrastructure
In a TV environment we have to check that all the components are compatible in format, form and codecs in order to have efficient workflows in place.
Among the basic and critical components that must integrate an HD workflow, we find:
- Capture systems.
- Transmission systems, backpacks, 4G, 5G.
- File ingestion systems and recording of internet sources.
- Monitoring and analysis of signals, both the use of multiscreens on led monitors, as well as frame and signal analyzers.
- Video and audio mixers.
- Video matrix, both 100% HDSDI matrices, and hybrid matrices
- In the case of a leap to IP television, with SMPTE 2110, traditional matrices are replaced by routers.
Glue, Converters, distributors, upconverters, downconverters, etc. These elements disappear if we migrate to an IP television, leaving just a few converters for equipment that is not compatible with the standard.
Digital production system, PAM with Shared Storage.
- Mobile production units, where the growing use of remote production means that these elements are increasingly reduced, thus allowing to minimize operating costs with remote work.
- MAM, centralized filing systems.
For TV stations, the recommendation I can make about formats nowadays would undoubtedly be to try to work in a single format ‘from home’, for example in HD with 1080i and go for a standardized TV production format such as XDCAMHD 422 at 50 Mbps. With some exceptions, having a single working format at file level greatly speeds up and improves the workflows of the different areas of a TV station that require the sharing of material and where immediacy is something to take into account.
In the future, in the medium and long term, XAVC is positioning itself as the substitute for XDCAM422 @ 50 for 4K formats, but this is something that right now looks a bit distant since it has implications beyond the capture of the format by the cameras.
If we are going for fiction production, or content production companies, we would be considering heavier formats, RAW for 4K capture and subsequent compression for proxy work (DNX35 or similar type).
In short, if the television environment is facing a technological renovation to migrate from SD to HD or 4K, the recommendation is to leap to HD, since 4K is still very expensive in order to be able to do so in all stages. If we are dealing with a small-size or a medium-size TV station, we could consider a leap to 4K based on IP technology such as NDI.
In the event of a renovation that seeks to update HD equipment, I would recommend looking for hybrid equipment and solutions that allow living with 4K or at least having the option of IP in the future.