Recently, Tom Kelcec, of Railfan & Railroad magazine, asked some questions about how we produce our shows, and more specifically about Raleigh D'Adamo's Washington Streetcar Films. Here are his questions and our answers. (Please note that our Catalog-On-DVD, available on all our DVD-Rs or by request, contains motion sequences illustrating the processing steps described below.)
TK: How do you transfer movie film to video e.g. machinery involved [projectors, if any, the video capture machine], adjustment of framing rates (16 and 18 and 24 fps to 30 fps video) to avoid flicker and duped frames? The DVD mentions "Dodcap" for film capture.
TGM: 16mm film gets sent out for transfer on either a Rank or Bosch telecine. There are many places which do this sort of work. Sometimes it is possible to negotiate a discounted rate by agreeing with the transfer facility that your films are lowest priority, i.e. that they will use it to fill in otherwise quiet periods.
8mm films we transfer in house. We use a telecine manufactured by MovieStuff, model Video Workprinter-XP, and a Sony PD-150 camera using its digital FireWire output. This transfers at approximately 6 fps directly to a computer hard drive. Each time the projector pulls down a frame, it sends a pulse to the computer. Dodcap is the program running on the computer that grabs a single frame via a FireWire card each time it receives a pulse, and appends it to an AVI file. The result is an AVI where each video frame corresponds to exactly one film frame. It plays back at 30 fps, faster than real time, although the capture process is much slower than real time. See the reason why below.
TK: How do you clean and lubricate films?
TGM: Usually we don't. If the photographer has taken good care of his films, it shouldn't be necessary. In the case of the Washington DVD, Raleigh's films had been projected only once, right after he got them back from Kodak, just to check and make sure everything was all right. They were extremely clean, and splice-free (except for the one splice in the middle of each roll where Kodak spliced the two halves of the split 16mm film).
TK: Your DVD seems to indicate that technology sharpens the images once they are transferred from film. What does this, how does it work? Vendor?
TGM: Let's work backwards through the process because that makes it easier to understand why each step in the process is made necessary by the step which is to follow.
Color, exposure, and gamma correction are done done using a plugin for Premiere called
ViXen. At this stage we don't do scene-by-scene color or exposure correction. In the case of Raleigh's films, it really wasn't necessary for most scenes - his exposure was spot-on, he shot almost exclusively on sunny days for consistency, and he stored his films carefully, so we was able to apply a blanket correction to each transfer roll, sometimes to groups of several rolls. Gamma correction is required of any film transfer to compensate for the difference in film's light sensitivity as compared to a video camera (which is what the whole video post-production chain is designed for). Since film has a logarithmic sensitivity to light, and a video camera is linear, if film is transferred to video and the shadow and highlight levels are properly set, the midtones will be too dark. We apply a fixed gamma correction to all the footage to correct the midtones.
Sharpening is also done using ViXen. It works pretty much the way the Unsharp Mask filter in Photoshop works, but with a lot more control over the process. It detects edges (places in the image where there is a jump in the brightness values between adjacent pixels) and increases the contrast at that spot to make the edge more visible, which gives a subjective impression of increased sharpness. Unfortunately, a sharpening filter can't tell the difference between the edge of an object in the frame, and the edge of a piece of grain in the emulsion, so it also increases the apparent graininess. Therefore, to get good sharpening, you first need to reduce the graininess.
ViXen does that, too, with what is called "temporal noise reduction" or frame averaging, which relies on the fact that an object in the frame, if it is not moving and the frame is not moving (as for example panning), remains in the same place in each frame, but grain is random and changes from frame to frame. So if you average several frames together, the grain tends to cancel out, but the objects in the scene remain the same and so aren't affected. Frame averaging is set to cut out wherever there is movement in the frame, because otherwise moving objects smear and leave a trail behind them, which is much more objectionable than grain. But frame averaging only works well even in the stationary parts of an image if these parts are very steady.
That's where SteadyMove
comes in. It's another Premiere plugin and it stabilizes images. Even though Raleigh shot using a tripod, the inaccuracies of an 8mm pulldown mechanism introduce a little shakiness into the image, enough to degrade the noise reduction step noticeably if not removed. SteadyMove can remove the shakiness, giving a video-steady image. But SteadyMove only works well on non-interlaced images, hence the reason for transferring one film frame per video frame. Temporal noise reduction and sharpening also work noticeably better on non-interlaced images.
So the workflow is:
Use SteadyMove to stabilize the image
Use ViXen to reduce the noise (grain)
Use ViXen to sharpen
Use ViXen to do color and gamma correction
This is done in one pass in Premiere by invoking the plugins in the proper order. It is much slower than real-time, so the computer works on the AVI files overnight. The result is steady, clean, sharp images running at 30 fps.
The final step in processing the film is to convert the 30 fps video to the correct speed, which in most cases is 20 fps. Most 8mm cameras were set to run at 18fps, and some actually did, but the simple relationship of 30:20 produces smoother results than 30:18. After Effects performs the speed conversion - it does a much better job than Premiere because it can blend the frames together, producing smoother movement. Alas, that makes for worse-looking freeze frames if a viewer hits the pause button, but we feel smoother motion trumps clear freeze frames for most viewers. (BTW, the frame grabs for the cover, ads, and the catalog are all taken from the footage before it is speed-corrected for this reason.)
For this production, we processed all the original footage, because we wanted to be able to edit to music, so we needed the footage to play at the proper speed. As it turns out, the longest part of the editing project (aside from sound effects editing) involved just figuring out where each shot was taken, and then selecting the best takes and assembling them in the correct order for each route. If we had it to do over again, we would do all this selecting and ordering before processing the footage, cutting each shot longer than needed, and then process only this footage. At that point, editing to music, as it turns out, goes rather quickly.
TK: Without the original film to look at, it is impossible to ascertain how much work was done to the movies, but, I would assume a lot. I have been rather amazed at the restoration work you have done in the past, and I think your Pittsburgh program demonstrated what was done (e.g. sharpness, color, taking out camera shake, and so on).
The Washington Streetcar footage appears to have been shot using a tripod, but what did you do in addition to improve the final product. I could not get over the fine color, smooth pans and so on, shot by an "amateur" in the early 1950s when he likely did not own (but might have) the higher quality 8mm equipment available.
TGM: Actually, Raleigh had very good equipment - a Bolex H8 with good lenses and a motor drive, and a tripod which he always used, ditto for exposure meter.
TK: As an aside, I have seen some of the same WWII footage used by different production companies (e.g. History channel, PBS) and in some cases the restoration work done by one makes the other look very foul: sharpness, scratch and dirt removal, color restoration, and so on. Of course, the dedicated producer and technician can appreciate their work, but will the public/customers realize it and make the effort and cost worthwhile?
TGM: Who knows? Many of our customers say they appreciate the quality of our work, but it's hard to tell how much is due to image restoration, how much to the accuracy of the commentary and shot sequencing, how much to use of music and sound effects, etc.
TK: There are many, many video editing packages out there. Some are for the MAC only, some for the PC only, some for both. Practically everyone I talk to uses something different. You like Adobe Premiere. Any short reasons why? And what platform do you use?
TGM: We use Premiere A) because it is a known quantity, and B) because it integrates well with the other Adobe products: After Effects, Illustrator, Photoshop, Encore, and Audition. Windows platform.
TK: Encore you indicate is used for authoring. Again, same questions and curiosity as above.
TGM: A) Because it does what is necessary in an authoring program (the ability to import a stream of subpictures using a script is absolutely essential for doing SynchroMapsTM, as is the ability to do Playlists, and most programs in its price range cannot do both), and B) same as above.
TK: From time to time I get DVDs that do not play well, and various "experts" have said it can be in the authoring, such as somebody editing on tape and then using a cheap DVD recorder to convert the analog (or digital) signal to burn a DVD real time. Others tell me that doing the authoring on a computer and letting the software takes its time, rather than being rushed, makes for a better outcome.
TGM: Perhaps there are two issues here; disc/player compatibility, and quality of MPEG encoding. If a disc doesn't play properly - skips or freezes, or won't play at all, or won't let you select some menu items - then it is probably because the player isn't compatible with the DVD. Many older players won't play DVD-Rs or DVD+Rs properly, especially if they were burned at high speed. On the other hand, with respect to picture quality, it takes a very expensive MPEG encoder to do a good job of encoding in real time - the cheap real-time DVD recorders don't do a very good job. (Although it's surprising they do as good a job as they do!) If you author using a computer in non-real-time (as we do) then the results are better, although it is a waaaay slower than real time process. Lots of overnights... luckily, computers don't need to sleep.
TK: Your maps and their interactive nature and the half-tone overlays are quite amazing. Was all of this done using "Synchromaps?" How long does it take to create the effects and maps used in your programs?
TGM: SynchroMapTM is TGM's trademark for the end result. The base map was created in Illustrator, animated in After Effects, and inserted into the DVD project with Encore using a script generated by a spreadsheet program. Actually doing the map animations was accomplished relatively quickly (a couple of days for all of them). What took the time was figuring out the correct location for each and every shot (something that was necessary in any event even if there hadn't been SynchroMapsTM).
TK: Was this software also used to create the menu and chapters?
TGM: The menus were created in Photoshop and then linked up to their proper destinations in Encore. There are no chapters. Each route in the Route Menu is a Playlist. A Playlist is a list of movies on the DVD in the order in which they will play. Each Playlist contains one or more segments that will assemble into a route. Each segment is a standalone MPEG movie - there are 54 of them on this DVD. For example, the segment between Friendship Heights and Georgetown is used only by route 30, so it appears in the route 30 Playlist. The segment between Georgetown and 7th & Pennsylvania Ave. is used by both routes 20 and 30, and so appears in both Playlists. The segment of route 30 between 7th & Pennsylvania and 17th & Pennsylvania appears in the route 30 Playlist, while the segment between 7th & Pennsylvania and Union Station appears in the route 20 Playlist. And so forth. This rather complex underlying structure was done in order to avoid having to waste bandwith by including shared segments multiple times. The user doesn't have to worry about any of this - just select a route and direction and hit Enter. The only drawback is that you can't execute a playlist backwards - if you want to backtrack by using the Previous (or <<) key, when you get to the head of the current segment, the next press of << sends you off into an undefined state. Maybe the next iteration of the DVD standard will fix this...
TK: The master map that shows the whole system was created using what?
TGM: Adobe Illustrator.
TK: As for the sound options, I assume there is one complete, synched-to-the-video soundtrack for each menu option. (Or...are there 3-4 separate programs on the DVD?)Either way consumes extra DVD space. How much does each sound track take up in terms of DVD space? Was "Audition" used for all of this?
TGM: Each segment (as described above) has four separate soundtracks, selectable using the Audio button on the DVD remote (on some remotes it is the Language button). You can also use the Setup menu. The grand total of all the soundtracks on the disc is about 900MB, relatively evenly divided between the various mixes. The soundtracks were all edited in Premiere - adding the sound effects was the longest single process in putting the production together. Audition was used to clean up and process individual sound effects before bringing them into Premiere. For example, we didn't have access to any trackside recordings of Washington PCCs on open track (on private right-of-way). The best recordings of PCCs on open track that we had were recorded at the Baltimore Streetcar Museum, but Baltimore streetcars used trolley wheels, which make a loud and distinctive noise as they roll along the overhead contact wire, whereas Washington streetcars used shoes, which are almost silent. So we fooled around with various equalizers in Audition until we succeeded in removing almost all of the sound of the trolley wheel from the Baltimore recordings. What little was left was covered by the sound of cicadas (which is a similar sound).
TK: Replication / Duplication -- I assume you replicate, which would be done by an outside vendor I assume. (If you duplicate, do you do this in house, or outsource it?)
TGM: New productions are replicated, outside vendor. The DVD versions of our older titles, which we will be announcing in due course, will be duplicated in house.
TK: There has been much written and many opinions on DVD rot and what media to use. Any thoughts you have along this line would be helpful as well.
Our experience isn't extensive enough at this point to have anything useful to say. Ask again in a year or two...