HOW BABYLON 5 IS TRANSFERRED TO DVD © 2001-2007 Henrik Herranen This page is http://www.iki.fi/leopold/Babylon5/DVD/DVDTransfer.html

How Babylon 5 Is Transferred to Video

1. Disclaimer

This article was originally based on the R1 The Gathering / In the Beginning DVD. With the new 16:9 episodes, while transfer of live footage has been excellent (with the exception of film dirt in the two first seasons), the effects have consistently been handled in a less-than-stellar way. This is especially maddening as the source material is inferior to the film material to begin with. Making it worse than it could potentially be makes one hope that there are multiple copies of the original 4:3 composite tapes so as to make it possible for someone to do the job properly in the future.

2. Motivation

3. Abstract

Although DVD has vast potential for presenting Babylon 5 in its long-awaited widescreen presentation, there are several hazards in the process, which will be discussed in this article. The main problem is that while the complete series (except The Gathering) was shot in a widescreen aspect ratio, special effects shots were not properly prepared in order to create a good-quality widescreen presentation. Even worse, it will be shown that the current methods of making effects widescreen are far from ideal. A solution for the problems is also presented.

4. Some Video Aspect Ratio Terminology

4:3 - The conventional NTSC aspect ratio you see on TV every day. Contains approx. 480 visible horizontal scanlines.

: Babylon 5's original transmissions, VHS tapes and Laserdiscs are offered in this aspect ratio.

Letterbox or LBX - A way to present Babylon 5's 1.78:1 material on a traditional 4:3 tv. With this method a widescreen image is shrunk so that it fits to a regular 4:3 TV. An unfortunate side effect is that one fourth of the active image area is left unused because of black bars that appear on top and bottom of the picture. Thus, in the visible area you have only 360 scanlines left.

: SciFi Channel's Babylon 5 transmissions are offered in this aspect ratio.

Anamorphic, 16:9, or Anamorphic 16:9 - A way to encode widescreen material so that there are no unused scanlines (in Babylon 5's case). The idea is that while squeezing the image horizontally so that the full width of 1.78:1 material can fit in a 4:3 TV, the same squeezing is not done vertically. Thus, if you watch a 16:9 transmission on a regular 4:3 TV set, people and things appear thin and tall. All 16:9 TV screens can show this data in the correct aspect ratio, as can 4:3 TVs with a so-called "16:9 squeeze button", a feature very common in Europe. The benefit of this approach is that you can have widescreen material and still retain all 480 scanlines. DVD players can convert this data to regular letterboxed material for people that can't do the unsqueeze in their TV sets, but in this case all the benefits of 16:9 encoding are lost, and you are back to 360 visible lines.

: Babylon 5 DVDs (except The Gathering) are offered in this aspect ratio.

Widescreen or WS - A Widescreen (1.78:1) image, achieved on video either by Letterboxing or by an Anamorphic transfer.

5. A Bit of History

In 1991, seven years after the series begun, SciFi Channel started presenting Babylon 5 in letterboxed widescreen. While there were some problems with some effects incorrectly composited (remember The Teapot from MotFL?), and some whole seasons transferred incorrectly, these errors were corrected for later showings and it was generally felt that these were the definitive editions of the series - so far.

Almost eight years since the first regular episodes of Babylon 5 aired, first telemovies The Gathering and In the Beginning were been transferred to DVD for anyone to buy, soon followed by the complete series. While The Gathering was always intended to be presented in 4:3 and is thus of little interest to this article (except that the transfer is proper and special effects work as they should), all other movies and episodes have been transferred in an anamorphic 16:9 aspect ratio, which is generally the best way to encode a widescreen DVD.

6. Theory of Transferring Babylon 5 to Video

6.1 How Babylon 5 Goes from Film to Video

After a show has been shot, the Super-35 film is transferred to a digital, high-resolution format. The good thing about using a high-resolution format is that later you can use that master to scale several different resolution versions (NTSC 4:3, NTSC 16:9, PAL, etc) without noticeable quality loss.

6.2 How Babylon 5 Special Effects Go to Video

There are several implications of the figures described above, and they all come down to this: there is no high-resolution master for the special effects shots. Thus, if anyone wants to make a Babylon 5 transfer to any other resolution or aspect ratio than standard 4:3 NTSC, it is simply impossible to retain full video quality. The only question is how much quality will be lost.

7. Examples of Transferring Babylon 5 to Different Aspect Ratios

All examples are presented vertically at approximately 1/2 of NTSC resolution. Horizontally the pictures have been scaled so that normal 4:3 images have a correct aspect ratio.

Resolution of the high-resolution images are not to be taken literally. I have no idea of what resolution is used in the editing system.

7.1 Example: Live Action Material



This is an example of how 4:3 (blue box) and Widescreen (red box) versions could be transferred from the current shot. Note that although I have chosen to make the boxes as big as possible, their size can be adjusted on a shot-by-shot basis if some details are to be emphasized.



In this picture we see the final 4:3 transfer. As the original high-resolution image has been scaled down, the end result still has full NTSC resolution and may look very good indeed.



These two images show how Letterboxed and 16:9 transfers would look. As with the 4:3 transfer, both are as sharp and clear as they can be, although the 16:9 transfer would look better with a proper 16:9 capable display device, as it has retained more information of the original high-resolution scan.

7.2 Example: Composite and Computer Generated Material

Unfortunately this theory was wrong. Regenerating effects would need a lot of handcraft and is at least for now outside the range of things that can be realized. Thus, we have only original 4:3 NTSC frames to begin with.



As can be seen, we have much less room to manoeuver than with the live action data. How can we get a widescreen transfer out of an image that does not have any extra side information?

There is only one way: cropping. Babylon 5's effects are supposedly generated in such a way that allows for matting the top and bottom of images so that you would get the correct aspect ratio.



Above you can see the cropped version of the 4:3 image. If, as in this case, the image is protected in such a way that no important information is lost when cropping, this is not such a bad way of making a widescreen transfer: the part of the picture that is not lost to the black bars suffers no resolution loss as it is not touched in any way. Thus, SciFi Channel's letterbox Babylon 5 has pretty much untouched special effects, with full picture quality - unless someone has screwed up something.

Finally, we'd want to make the ultimate, 16:9 transfer. And it is here we run into trouble, big time.

To create the 16:9 version, we should start with the previous letterboxed image, since that's the best and only widescreen image we have available. This image that has 360 active scanlines must be converted to an image that has 480 scanlines. (Note, that as my images are at half resolution, they have 180 and 240 active lines, respectively.)

It is probably very easy to understand that when upconverting something from a lower resolution to a higher resolution, you cannot expect the end result to have the full resolution that the higher resolution image can present. What may not be quite as intuitive is that you cannot even get to the resolution of the lower-resolution image!

What am I saying? Yes, I am actually saying that for a 16:9 letterboxed transfer, there is no way that the composite and effects shots can look even as good as in the Letterboxed version. The difference need not be big, but 16:9 will in this case necessarily be worse than letterbox.

Does this sound a bit nasty? Sorry, it's worse than that. See the pictures below for the gory details.



Above you see two pictures that show how the 16:9 transfer could be done. The picture on the left is the way the resolution conversion has actually been done, and the picture on the right show how I would do it. Let's look at the pictures again, but this time upscaled:



Above: The way Babylon 5's anamorphic version is actually done.



Above: The way I would scale Babylon 5 to 16:9 anamorphic.

As you (hopefully) see very clearly is that the picture presenting the way Babylon 5 has been transferred, looks quite bad. Some horizontal lines have been doubled, and the picture's overall look is fuzzy and unclear.

You may have scaled bitmap pictures on a computer without ever getting results this bad. You might even ask yourself: "Surely nobody would be so stupid to make such an ugly transfer when it's so easy to make it properly." That's a good question. Unfortunately, in the video world, scaling gets a bit complicated. This will be described in the next chapter. 8. Field-based Vs. Frame-based Video Transfer One nasty detail in video picture that always (including this case) comes to bite you in the ankle is that unlike film frames, video picture is transferred not in frames, but in fields. I won't go into details in why this choice was made in the late 1930's, but suffice to say that it made it possible to transfer a HDTV signal (as NTSC was called at that time) in approximately half the bandwidth that would otherwise be required, allowing for two times the number of channels otherwise available.

The example picture above shows how a hypothetical, 12-line interlaced TV system works. To show the full frame, first odd scanlines are presented. After this, even scanlines are presented. If presented fast enough, these two video fields meld in the brain and form the full frame presented on the left. Short summary: as all other analog video systems, also NTSC uses interlaced video. NTSC's field rate is 60 Hz (actually 59.94 Hz, but who's counting?), and the frame rate is half of that, roughly 30 Hz. It is no coinsidence that Babylon 5's special effects have been generated at this same rate, 30 frames per second. It has the potential of making movement look smooth and nice compared to 24 fps live action material, which needs some tuning to fit into the 60 fields/s video system. Now that we understand these basics, we can finally have an informed look at how Babylon 5's special effects are converted to 16:9.

Originally, when Babylon 5's effects were created, they were rendered at 30 fps, and stored to a computer in this format (F1, F2, F3 and F4). To transfer the images to video, they are separated into video fields. For instance, F1 is broken to f1.1 and f1.2. Likewise, F4 is broken to f4.1 and f4.2. At some point the data is letterboxed. Although it doesn't matter where this is done, I've presented the step here for clarity. Thus, we've now lost the supposedly unimportant bottom and top of the effects shot. It is worth noticing that at this point, the information of which field-pair contain data from the same source frame, is lost. Thus, while f1.1 and f1.2 represent the same frame in this example, this could also be the case for f1.2 and f2.1 (f2.1 not shown in the picture). Signal path A presents how Babylon 5's transfer is done. First A1 removes the unneeded letterbox lines. Then, A2 upscales the picture by 33% vertically. This is the very step where picture clarity is lost. A3 regenerates interlaced fields. A4 isn't necessarily performed at all, but the combined frame F'1 is a convenient way to show how the end result will look on your screen. What went wrong with transfer A? The problem is that upscaling was done to interlaced video fields which, if taken from a signal processing view, is horrific mishandling of a completely innocent signal. So, how should things be done then? Signal path B shows my suggestion of how the effects should be transferred. First, F4 is broken to video fields f4.1 and f4.2 just as happened with F1. But in this case, B1 combines two video fields to create a full frame. Then, this complete frame is upconverted to create directly F'4. If needed, interlaced fields can be easily created from F'4 if that is required. You may again ask why Babylon 5 isn't converted in this way which seems so much easier to do. The reason is that there is really no guarantee that the original fields are aligned. Also, Babylon 5 has several shots where live action is in 24 fps but CGI is in 30 fps, making it impossible to sync perfectly to the source signal's frame rate(s). It is worth noting that if field-combining fails, the end result will look considerably worse than any of the methods presented here. Thus, to get correct conversion, there needs to be automatic logic combined with some human interaction for verification. There are two reasons why I am so concerned with this. One is that I wanted to have Babylon 5 on DVD with as high quality as possible. The other is that I know the problematics involved in making these effects. My company created a working prototype 3D graphics chip in the late 1990's. The evaluation card that had the chip had both TV inputs and an output. In addition to defining the chip's interlace flicker filters, I made some software to the card that did exactly what I described earlier: it scanned an NTSC, SECAM or PAL signal, examined movement and used the detected movement to sync to the actual frame rate in the source material. When executed properly, syncing worked very well and the system worked wonderfully with video projectors and computer monitors, and allowed for clean video conversions across video systems. 9. Summary If given original 4:3 or Letterboxed Babylon 5 effects video fields in some known high-quality digital video format (plus some time and money), I could make a better CGI + composite transfer than what current DVDs show. And after all these years, now that it is 2007, I still am sorry that the shots haven't been transferred in the best possible way to widescreen. Not at all diminished by the terrible later TV movies, original Babylon 5 is still great and needed the best possible DVD transfer. Finally: Proof 2003-04-21 When I originally wrote the previous article more than a year ago, I had strong feelings that my theory was correct. However, because no-one could provide me with high-quality, bit-accurate B5 DVD scans, I couldn't really prove everything that I said. Now I can. Below is one frame digitized from the very first shot of Midnight on the Firing Line, from the R1 DVD (which is, actually, region-free). This is one of the last frames of that first shot. I have taken the liberty to crop extra black space away to make the file and image slightly smaller. I also made it black and white to ease my own job and to make the artifacts appear more clearly. The frame is presented below: Now that I finally had good, accurate frames ripped straight from the DVDs, I immediately decided to try to compensate for the wrong filtering that I described earlier in this article. The task proved to be doable in four hours and resulting in merely 3.5 kilobytes of C source code. The reverse-handled and rescaled image is below: So, there it is. Download the two images and flip through them back and forth. Imagine the images on a big projection-screen television where all differences appear 10 times bigger. There you have it. I have used no extraneous edge enhancement or other dishonest trickery to prove my point, and I very much doubt that they would have been of any help, as I was trying to regain real resolution that actually existed in the original 4:3 masters. What my software did was as follows. First it divided the original interlaced frame F'1 to two interlaced fields. Then I used reverse filters to acquire f1.1 and f1.2, and then combined them to produce the original, letterboxed frame F1. After the original, unbroken complete frame F1 had been regenerated, it was used to create F'4, which was scaled in the way it should be done. The result is what you see above. If you for some reason can't easily compare the pictures above, I've prepared two partial enlargements of them, where the original broken frame F'1 and my corrected F'4 are shown alternatively. The picture that looks unclear and where some details appear two times is the original, and the sharper one is my properly scaled version. Detail 1:

Detail 2:

This was what I would have liked to have seen in the Babylon 5 16:9 DVD transfers. Subtle Differences Between R1 and R2 DVDs There has been some talk about how R1 (actually all-region) and R2 versions of Babylon 5 first season DVDs have some CGI transfer errors, and that they appear in different places in the two existing versions. What has been talked less about is that the CGI and composite shots for these two versions seems to subtly vary all over the place so that the watcher of both versions seems to get a picture that these shots have been transferred independently of each other. If this sounds improbable, see for yourself the very first shots of the first five acts of Signs and Portents. The following pictures have been scaled to similar size to make comparing easier. No cropping has been done. I have made it certain that all image pairs are aligned in time with the accuracy of one frame.



Nr R1 R2 1

Nr R1 R2 2

Nr R1 R2 3

Nr R1 R2 4

Nr R1 R2 5

Nr R1 R2 6

Nr R1 R2 7

All these subtle differences leads me to believe that for some odd reason the R1 and R2 DVD masters were cropped, and the titles were added at different times, perhaps even by different people. The reason for this escapes me. Perhaps JMS would have some insight into this?

Second Season: Special Effects Still Problematic

There are also additional errors in the 2nd Season set, most annoying for me being the opening title font which is not the same as it was when Babylon 5 was first aired in its NTSC incarnation (but, curiously enough, it is the same as was used in first proper PAL versions). Also the end title music is wrong: instead of the Second Season faster theme, the First Season theme has been used. And, in the NTSC version, Delenn's image is wrong in the two first episodes (it should be an image of First Season Delenn, as it correctly is in the PAL version).

As with the First Season, framing of SFX is different in PAL and NTSC versions. This can be seen, for instance, in Fall of Night's Keffer's Starfury's surveillance camera shots: in the PAL version, the word "Keffer" is completely visible, while in the NTSC version, only the upper part of the letters can be seen (and the NTSC version flickers like crazy on a proper 16:9 display device because of the way the SFX are converted).

While all of this did not stop me from buying five copies of the PAL Second Season box set for me and my friends, I would really, really wish they would try to get their act together for Season 3. It's really not that hard. And, really, there are no alternatives since the later 2nd Season and all of the 3rd Season were never published on Laserdisc.

Third Season: New Visions

Third Season Picture Quality

The only gripe I have with the live action footage is that the framing looks to me much more 4:3-oriented than what it was during the first season. A notable exception is War Without End Part 1 which seemed to make full use of the 16:9 area. One distracting thing, though: all first season footage for both War Without End episodes have been transferred using the special effects process, i.e. 4:3 cropped to 16:9. This is also true for all reused footage in black and white flashback scenes. (By the way, when flashback footage is B&W anyways, wouldn't it had been clever to show it also in original 4:3 format to underline that it is old? Now they lost a chance not to crop the 4:3 footage even further.)

I expect to get my hands on the R1 version in a few weeks, and then I'll comment more on the effects transfer. However, judging from the R2 transfer I saw, it might actually be that they have done it slightly differently this time around. But no definite comments before I actually have a chance to see it.

How Much Quality Do We Lose With Composites?

Background

For some reason all reused footage from past seasons and episodes are presented in the 4:3 -> 16:9 cropped format even if they don't contain any computer graphics. Thus, to see how much is lost from the original, high-quality film material, you only have to have a look at the "Previously on Babylon 5" sections of War Without End or A Voice in the Wilderness and compare them with the places where those shots were originally used. I've selected to do exactly this with War Without End.

Before we go to the actual pictures, let me make one thing absolutely clear. I am not, repeat not claiming that cropped 4:3 could be made to look as good as original film material without completely recreating all special effects, which as we know is inpractical, and if done would probably lead to something akin the Star Wars travesties. This is because all original CGI models and setups have been lost. Here I am just showing how big the difference is without commenting a lot on how much of it would be avoidable.

Pictures

Nr WWE1 Real 16:9 WWE2 Cropped 4:3 to 16:9 1 1

Nr WWE1 Real 16:9 WWE2 Cropped 4:3 to 16:9 2

Nr WWE1 Real 16:9 WWE2 Cropped 4:3 to 16:9 3

Nr WWE1 Real 16:9 WWE2 Cropped 4:3 to 16:9 4

Nr WWE1 Real 16:9 WWE2 Cropped 4:3 to 16:9 5

Third and Fourth Seasons: Nothing New in NTSC Land

Special effects and composite shots are, however, still converted in the very same half-ass way as before. In addition, there are some errors and weirdnesses common to both NTSC and PAL transfers. The whole Garibaldi arc in the beginning of Between the Darkness and the Light is in the cropped widescreen format, probably because of some confusion over the fact that the particular material was originally supposed to be in Intersections in Real Time, but was bumped to the next episode according to JMS. Also the opening titles of The Deconstruction of Falling Stars are different from the one in the original airing, as Claudia Christian in them. In the original version she was absent because of payment reasons.

Fifth Season: Same Old, Same Old

Also, there seemed to be more film dirt than in the previous two seasons, although I cannot really be hundred percent sure. Too bad.

All in all, I've found the Babylon 5 DVDs to be a mixed bag. First and foremost I am really, really happy that they exist at all. Also, the new film transfers have improved picture quality significantly - or would have if there weren't quite that much film dirt. However, at the same time I still cringe because special effect shots were not handled as well as they could have, recropping them and thus breaking both picture composition and quality. Leaving effects and composite images at 4:3 along the 16:9 (or slightly narrower) film material would certainly have given the best picture quality.

All in all, even with all its shortcomings, I'd recommend Babylon 5 DVDs for anyone even slightly interested in science fiction or good storytelling - especially the inexpensive German edition.

2005-03-10: The Movie Collection (R1)

The Gathering

However, audio has been updated to 5.1 and although there are no big surprises there, dialogue stays nicely in the center channel. The JMS and John Iacovelli commentary is insightful as usual (haven't listened to the other commentaries in this box set yet).

This movie serves as a good example of how good CGI and composite shots looked before being cropped and badly scaled for the 16:9 versions.

In the Beginning

Audio has been updated nicely to 5.1.

Thirdspace

The River of Souls

The River of Souls is a nice, clean transfer (with the natural exception of special effects and composite shots). However, as special effects are rendered only at 24 fps instead of 30 fps that had been used earlier, and as the effect shots have not always been properly motion blurred, movement can at times look jerky.

One opportunity missed was flagging the material as a 24 fps source. During earlier seasons this would have been problematic because of mixed frame rates. However, now it would have been possible and would have made it easier to watch the DVDs with some progressive devices. However, the material is incorrectly flagged as 30 fps.

A Call to Arms

2005-03-09: Crusade (R1)

As with the TV Movies, everything is now 24 fps, including special effects. Nevertheless, the source material is incorrectly flagged as 30 fps.

If you have a chance, have a look at this set. You will notice that in many places it is very difficult or completely impossible to say whether what you are looking at is pure film footage or whether it is a composite shot. That is how Babylon 5 used to look before getting the anamorphic widescreen treatment (which increased the quality of film-only shots and decreased the quality of composite and CGI shots).