The movie industry is largely to thank for the introduction of HDTV (High Definition TV) into the subconscious of home viewing, not because they invented it but simply because they champion its cause. Television broadcasters have been pushing the limit for many years and only in recent years have we finalised a standard (or several standards) that are recognised worldwide.
After the establishment of the widescreen film format, it was soon discovered that audience members in the first few rows of a theatre experienced a level of participation and immersion in the movie-going experience previously unmatched. It was not long after, the idea of bringing this experience to television viewing and into the home was addressed.
The term high definition was bizarrely inferred upon the television systems of the 1930s and 1940s beginning with the British 405-line black-and-white system, introduced in 1936; like I said not as new as we were led to believe. However, it, and the American 525-line NTSC system established in 1941 were only high definition in comparison with previous mechanical and electronic television systems. Today, the American 525-line NTSC system and the European 625-line PAL and SECAM systems are only regarded as standard definition (SD).
In 1958, the U.S.S.R. created Тransformator (Russian: Трансформатор, "Transformer"), the first high-resolution (definition) television system capable of producing an image composed of 1,125 lines of resolution for the purpose of television conferences among military commands; as it was a military product, it was not commercialised.
In 1969, the Japanese state broadcaster NHK first developed consumer high-definition television with a 5:3 aspect ratio. A slightly wider screen format than the usual 4:3 standard that we were familiar with; until recently, as widescreen sets grew in popularity. However, the system was not launched publicly until late in the 1990s. So you hopefully start to realise that although we seem to think HD is a relatively new format, its foundations have been around for an extremely long time.
Sony and NHK developed a high definition TV system in the late 70's that was introduced to producers in the film industry in the early 80's. Dubbed NHK Hi-Vision, this system was capable of producing a picture that allegedly had the same clarity and level of detail as 35mm film.
In 1983, the International Telecommunication Union's (ITU-R) set up a working party with the aim of setting a single international HDTV standard. One of the thornier issues concerned a suitable frame/field refresh rate, with the world already strongly demarcated into two camps, 25/50Hz within Europe/UK and the American 30/60Hz, related by reasons of picture stability to the frequency of their mains electrical supply (110v). Through the 1980s, HD went through many incarnations and arguments over its standard raged, not least whether the standard should be frame or field based. While a comprehensive HDTV standard was not in the end established, at least agreement on the aspect ratio was achieved. Initially the existing 5:3 aspect ratio had been the main candidate, but due to the influence of widescreen cinema, the aspect ratio 16:9 (1.78) eventually emerged as being a reasonable compromise between 5:3 (1.67) and the common 1.85 widescreen cinema format.
Several standards remained which were ratified by SMPTE and gained recognition for use within the television industry. However, even that limited standardization of HDTV did not lead to its adoption, principally for technical and economic reasons. The biggest issue was over bandwidth for broadcast. Early HD transmissions were over 4 times the size of SD. In addition, recording and reproducing an HDTV signal was a significant technical challenge in the early years of HDTV.
It was not until the early 2000s that technology had progressed enough to deliver sufficient storage capacity and processing power to support compression algorithms powerful enough to make HDTV affordable for consumers and ultimately profitable for broadcasters and other program makers. The main enabling factor was the transition from analogue to digital TV standards. Digital compression methods such as MPEG-2 and MPEG-4 allow the bandwidth of a single analogue TV channel (6 MHz in the US) to carry up to 5 SD or up to 2 HD digital TV channels. Current HDTV broadcast standards include ATSC (US) and DVB (Europe, and most of the rest of the world). HDTV can also provide 5.1-channel surround sound audio using the Dolby Digital format. Most developed nations have plans in place for transition to digital television, but not necessarily or exclusively HDTV; for example, on 17th February 2009, the US intended to terminate all full-power terrestrial analogue broadcasting (although some smaller local stations have later deadlines), with both standard definition TV (SDTV) and HDTV being allowed.
In the UK, the standard definition analogue system is scheduled to be phased out by 2012, with the gradual introduction of HD as well. All new TVs have a digital system installed (freeview), or you need to purchase a set top box, which either utilises an aerial of a satellite dish.
STANDARD FRAME OR FIELD RATES (DTV = DIGITAL TELEVISION)
Why am I mentioning all of this, in truth I find it interesting. However the main reason is to make you understand just how many formats, or what I will term as deliverable’s you will need to achieve from a full DI project or master timeline. Not only will you need to deliver the master negative, you will also need to deliver a clean negative (no text version), plus an HD version in progressive and possibly interlaced as well. A myriad of American and European versions in 4:3, 16:9 or 14:9 for the BBC, probably versions with subtitles or anything else deemed appropriate, therefore you will need to have an understanding of many different formats.
Remember your master timeline will probably have been mastered using 24 fps material, if it came from film. The UK version will be 25 fps, a simple 4.1% speed increase. The American version is 30 fps, so 3:2 pull down will need to be inserted into the imagery for play out, or on play out. The deliverables are a massive part of the Digital Intermediate workflow and an understanding of all of these different formats is extremely helpful.
The final thing to note is how the sound will be supplied to you to add to the deliverables. Keeping in contact with the sound editors can make or break the final marrying of these two very separate parallel processes. Remember your final master has to be exactly the same as the final edit, otherwise sound timings and even worse, lip synch will be misaligned. It is generally good practice to supply a final copy of your edit/master timeline to the audio post house so they can do a final check against their audio.
This may cause other problems, in that you are working at 24 fps and they will more than likely be working at 25 fps. Possibly in a low resolution such as Digibeta or even a Quicktime derived from the basic offline edit? Certain Editing stations on play out add an extra frame to the playout, others do not and you may need to form a stretch to match – either way communication is of utmost importance.
HD DVD & BLU RAY
A quick note on HD DVD or High-Definition Digital Versatile Disc, HD DVD was designed principally by Toshiba, and was envisaged to be the successor to the standard DVD format. However, in February, 2008, Toshiba abandoned the format, announcing it would no longer develop or manufacture HD DVD players.
HD DVD (3x DVD) is derived from the same underlying technologies as DVD except HD DVD utilises a red laser and is capable of three times the bandwidth of regular DVDs. Blu Ray, hence the name, employs a blue laser with a shorter wavelength. It can store about 3¼ times as much data per layer as its predecessor (maximum capacity: 15 GB per layer instead of 4.7 GB per layer).
Much like the VHS vs. Betamax format war during the late 1970s and early 1980s, HD DVD was in a "format war" with rival format Blu-ray Disc to determine which of the two formats would become the leading carrier for high-definition content to consumers. In 2008, major content manufacturers and key retailers began withdrawing their support for the format. Toshiba's withdrawal from the format ended the high definition optical disc format war, effectively making rival Blu-ray the dominant format for high definition video discs. I am hoping the better of the two formats won. However being old enough to have had an original Sony Betacam with remote (a wired brick), I hanker after that format, in my humble opinion it was far superior, have they made the same mistake only time will tell?
I mention DVD briefly, in general this is a specialised format and the DI will only need to provide a master (tape). Compression ratios, depending on the film are different and can be changed over the duration of a film. Certain parts of a film may require less compression and other areas may need more to fully fit this onto a disk. It’s a specialist job, although quick rough and ready DVDs may be asked for by the production, be prepared, which are needed for test screenings and other work in progress viewing's, not everyone will be able to attend.