…είχα σκοπό να το ανεβάσω χώρια μια και η αναφορά είναι για την δημιουργία DVD από τα Master (ειδικά κλασικών ταινιών…) νομίζω ότι συνάφεια του θέματος το επιτρέπει… η αναφορά είναι από ένα παλιότερο άρθρο στο Laser Examiner …
It is a jungle out there. The cliché fits the DVD market perfectly at the moment; and it also seems to be applicable to the scores of authoring houses that have to combat an ever increasing (and seamlessly endless) flood of films coming their way. With errors occurring every week such as soundtracks being out of sync (albeit slightly), inaccurate color timing and color corrections, even whole sequences missing - what are the causes ? And what the remedies ?
Despite their ever increasing numbers, post houses seem to struggle when it comes to handling the everyday "onslaught". Technically, the developing trend is ironic: although encoders have improved dramatically in the last five years, have become much faster and can produce an MPEG-2 image of near perfect precision within the limitations of the format the quality on most discs is actually on the decrease. And this trend is noticeable in most studios and labels.
That makes it so aggravating to many viewers, especially those with better equipment. The knowledge that there is such a thing as better mastering has resulted in a growing number of critical comments also from the side of the "makers". By now, the effects of a more lacklustre mastering and encoding are even visible on normal screens - and thus moving into the domain of the mainstream viewer.
Technology does allow for much better quality - almost flawless releases such as "V - The Miniseries", the Japanese Editions of "The Terminator" or the "Gladiator (Superbit Edition)" presented visual excellence - and yet, so many other releases fall far short of that mark. "Gone With The Wind" was excellently scanned in 2K and mastered in the so-called "UltraDefinition process" to insure the 3-strip Technicolor elements would fit perfectly.
But the encoding to DVD was littered with artefacts, as were the releases of "Singin In The Rain" and many others. But why ? In many cases, the answer appears to lie in the massive workload, paired with a steadily declining profit margins resulting in less time for a project and less investments in the best equipment.
As we reported here before, the number of releases suffering from the "run-off-the-mill syndrome" is rising; with marketing decisions weighing heavily when it comes to the quality of the discs. Often is also a lack of good coordination and planning a cause.
With a flood of films and TV series to be marketed, making the most out of the quality of the digital source tapes when encoding to DLT (and subsequently DVD) is not only a tough job considering the limited time that is spent on each film/series - the individual title is also reduced to a mass product in every sense of the word, and very often not even big blockbusters get the attention they deserve. The reasons for this are many.
For one, the encoding of the films is very often being done way before the actual release is finalized. Extras are planned and produced later on, not rarely a long time after the mastering and encoding process - with the possibility that during that (long) planning stage some or even all of these extras are skipped, for financial or legal reasons, among others. The allotted space then just remains empty; no new encoding is made. The poor "exploitation" of the disc space is also due to limited time of preparation and testing. Very few discs are made using 2-pass methods, where the film is analyzed sequence by sequence - and the GOP structure aligned to the best way possible. A simple, default setting is all too often used instead; in which all films, black and white as well as color; video based interlaced signals @30fps as well as film-based 480p 24 or 576p 25 material is encoded the same way
MPEG encoding is literally like walking the many roads that lead to Rome. Because of the less than strict guidelines and wishy-washy interpretations of the standards of the format(ing) each manufacturer can do pretty much everything with the DVD standard and still call it correct.
The differences of encoding B/W material and highly detailed color material are just as often not taken into account as the difference between encoding film and video sources - or it is simply ignored by either using default settings in the encoder, or , even worse, using the wrong encoder all together. Sometimes, source material is encoded using the wrong field domination, or in a forced interlaced mode.
Warner Bros used forced interlaced encoding on several occasions, especially on TV shows - NIP/TUCK being the most prominent example; but the studio is not alone.
Instead of issuing the hit series in 480p 24 progressive CBS and Paramount offered forced interlaced 30fps encoded material (forced bob) of CSI and CSI Miami - except for Season 4 of CSI. MGM had the regular (!) occurance of field swaps on the R1 editions of STARGATE SG-1. On "normal TV sets" the result of forced interlaced material or the wrong field domination is less detectable; but on projection equipment it very much is. The picture, in effect, is marred by interferences such as field combing, very visible line structure and substantial loss of detail and sharpness.
We tested a number of titles regarding the mentioned "problems". Though we cannot list all the respective results individually here, what we can give you is a general idea of a trend that is continuing to develop. The results are quite interesting, as some studios seem to follow a clear pattern in planning and actual mastering of the various releases: Warner Bros, spearheading the (welcome) release of classics in form of Boxed Sets - have the mastering and encoding made completely separately from the planning of the extras. One thing all of these WB issues have in common: the maximum bitrate of the encoder is set to a very low 7.5 Mbit/s; a setting designed for saving disc space, not making the most out of it. With that in mind the fact that the newly issued collections of BETTE DAVIS, JOAN CRAWFORD, THE THIN MAN as well as THE ASTAIRE & ROGERS COLLECTION Vol 1 (putting aside the previously released single items here, these are "another matter") are all "underachievers" when it comes to disc capacity used and encoding performance should come as no surprise. Nonetheless, the results are very visible. For instance, SWING TIME, part of the ASTAIRE & ROGERS COLLECTION, must have been an enormous challenge in terms of mastering. There are countless problems with scratches and density on 35mm due to the poor state of the surviving elements - but, the harsh encoding where much of the grain was filtered, the scratches "sweetened" (i.e. softened and blurred) and artefacts are "left behind" this picture did not deserve. Even though this may be the best presentation so far on HV, we do not get to appreciate the enormous work that went into the restoration of the film elements. The cleanup was also not without mishaps; the scene at 28:32 (a single frame "rundown" here) clearly shows that two frames identical to the previous two ("leftovers" from another 35mm dupe element that is the basis of the next shot) were not cut from the digital master as they should have been, resulting in a frame jump. The DVD could have been much better with the proper treatment - and the irony is: it would have cost just the same. The used disc space is here, including almost an hour of extras, merely 6.06 GB (!!) out of 7.96; a very clear indicator that the film was encoded first, "on the fly", for a single layer - and without knowing how many extras will be put on the disc or what length these would have. The analysis of the bitrate of the extras suggests that SWING TIME, the film itself, was given less than 4 GB of the already reduced total capacity. Talk about driving on a highway in the second gear ...
Yet, there is such a thing as worse: THE GRETA GARBO SIGNATURE COLLECTION exhibits a number of titles where disc space (and quality) is thrown out of the capacity window: QUEEN CHRISTINA is encoded @ 99 Minutes for a Dual Layer with 4.88 GB out of 7.96 possible, NINOTCHKA reaches just about 5.25GB - leaving almost 3 GB of better quality capacity unused. And for ANNA CHRISTIE (for lack of a new master) a very old Standard Def 1-inch C master (!!!) was used, as was on FLESH AND THE DEVIL - where the video restoration of Kevin Brownlow dates back to 1988. Now, one of the arguments that is an evergreen when it comes to the issue of using the maximum capacity of the DVD is that maximizing and a high bitrate does not equal good quality. True - but only if the source master itself is poor or the encoder is handled wrong. Why put good space to waste, if the master is a superior one ? Warner, understandably, wants to make as much of their catalogue available as possible before the DVD craze is over - but that intention comes increasingly at a cost to the high expectations of the long waiting consumer. WB and the other studios can do better - as many other examples have shown. So, what would be the best way of coordination, mastering and presentation ? In the following, we retrace a few of the steps that lie between the best film elements and their duplication in the best way to the final, Home Entertainment, format.
