Movie Making Manual/Post-production/Telecine
Telecine (otherwise known as "TK") is the process of transferring motion picture film to a video format, such as television, or a machine used to complete this process. Telecine enables a motion picture, captured originally on film, to be viewed with standard video equipment, such as televisions and video cassette decks. This has allowed producers and distributors working in film to release their products on video and allowed producers to use video production equipment to complete their film projects.
- 1 Basic principle
- 2 Frame rate differences
- 3 3:2 Pulldown
- 4 One light, best light and scene to scene
- 5 History of Telecine
- 6 Amateur telecine of Super 8mm footage:
- 7 Resolutions
- 8 2- and 3-perf telecine
- 9 External Links
In a simple telecine, white light is shone through exposed and developed motion picture negative (positives can also be used.) As in a projector, the film filters the white light into different colors, according to the image on the film, except in a telecine this image is projected not onto a screen, but onto a charge-coupled device (CCD) or vidicon tube. The CCD converts the light into electrical impulses which the telecine electronics modulate into a video signal which can then be recorded onto video tape, or broadcast.
The most complex part of telecine is the synchronization of the mechanical film motion and the electronic video signal. Every time the video part of the telecine samples the light electronically, the film part of the telecine must have a frame in perfect registration and ready to photograph. This is relatively easy when the film is photographed at the same frame rate as the video camera will sample, but when this is not true, a sophisticated procedure is required to change frame rate.
Frame rate differences
In countries that use the PAL or SECAM video standards, film destined for television is photographed at 25 frames per second. The PAL video standard broadcasts at 25 frames per second, so the transfer from film to video is simple; for every film frame, one video frame is captured. Theatrical features originally photographed at 24 frames per second are simply sped up by 4% to 25 frames per second. This can cause a noticeable increase in audio pitch, which is sometimes corrected using a pitch shifter. (Note: frames per second is sometimes refered to as frame/s' or fps.)
In the United States and other countries that use the NTSC television standard, film is generally photographed at 24 frames per second. (Only programs aimed directly for television in the USA are shot at 23.976 fps.) Color NTSC video is broadcast at 29.97 frame/s. For the film's motion to be accurately rendered on the video signal, an NTSC telecine must use a technique called the 3:2 pulldown to convert from 24 to 29.97 frame/s.
Similar techniques must be used for films shot at "silent speeds" of less than 24 frame/s, which include most silent movies themselves as well as many home movies.
Some High Definition video recorders can record directly to 24fps (23.976fps) or 25fps so no interlacing is required. You can find out more at High-Definition Telecine.
The 3:2 pulldown is accomplished in two steps. The first step is to slow down, or "pulldown" the film motion by 0.1%. This speed change is unnoticeable to the viewer, and makes the film travel at 23.976 frame/s. (This is done simply by slowing the projector.)
The second step of the 3:2 pulldown is the 3:2 step (which adds the extra frames needed for the conversion.) At 23.976 frame/s, there are 4 frames of film for every 5 frames of NTSC video:
These four frames are "stretched" into five by exploiting the interlaced nature of NTSC video. For every NTSC frame, there are actually two complete images or "fields," one for the odd-numbered lines of the image, and one for the even-numbered lines. There are, therefore, ten fields for every 4 film frames, and the telecine alternately places one film frame across two fields, the next across three, the next across two, and so on. The cycle repeats itself completely after four film frames have been exposed, and in the telecine cycle these are called the "A," "B," "C," and "D" frames, thus:
Note that the pattern in this example is actually 2-3, 2-3. The name "3:2 pulldown" is an archaic reference to the pattern that was used by older telecine equipment. The modern telecine uses a 2-3 technique.
"3:2 pulldown" creates error in the video signal that can be clearly seen in the above image. This is one reason why NTSC films viewed at home rarely appear as smooth as when viewed in a cinema. Some line doublers and most software DVD players are designed to detect and reverse 3:2 pulldown, thereby recreating the original frames.
One light, best light and scene to scene
The color of the frame can be controlled during the telecine process. This section needs to be expanded to explain one light, best light, and other terms used in the telecine process which effect the coloring of the frames and the consistency of the color from scene to scene.
Briefly, a one light transfer means that footage is transferred with no regard to variations in exposure on the original negative i.e, the telecine is set at one value to transfer all of the footage. This is the standard first step when transferring rushes to tape, it's quicker, since it requires no intervention on behalf of the telecine operator, and is therefore cheaper. Best light means that footage is graded to look it's best in every take and scene, matching original lighting conditions and the desires of the Director and DOP. Finally, scene-by-scene tries to match the light and coloring of each scene, usually after picture editing is complete. All of the above can be done with either traditional methods (photochemically etc) or digitally.
History of Telecine
Before the invention of video tape, telecine was used only to convert motion pictures for immediate broadcast via television.
After the invention of video tape which can be used to store motion pictures, the telecine process was also used to convert motion pictures to video tapes or LaserDiscs for distribution.
By 1987, computer editing systems such as the CMX6000 became available to edit motion pictures. Somehow, the film dailies from a motion picture (or a television drama that was shot on film) had to be converted to a format that can be used by computer editing systems. In the case of the CMX6000, this computer editing systems controlled the playback of LaserDiscs containing the film dailies. To get the film dailies onto Laser Disc, the film dailies had to be telecined. The CMX6000, EditDroid, Ediflex or Montage did not actual store the images in the computer.
A few years later, after digital video formats for computers (such as QuickTime) were invented, there needed to be a way to transfer all the frames of the film dailies onto hard disk drives of computer editing systems so the images and sound for a motion picture or television drama can be edited inside the computer, not externally as with the CMX6000, EditDroid, Ediflex or Montage. The only practical option was to telecine the film dailies to video tape (which is a cheap storage media) before digitizing each of the frames of the video into data files for the computer editing systems.
Only in the last few years, can you telecine dailies directly to computer disks (rather than video tape.) Be aware that most post-production houses today still cannot telecine to hard disk drives so ask before you decide which film lab you will use to develop and telecine your dailies.
- Telecine Dailies - For Theatrical Release
- When movies are edited in a computer editing systems, the film negative for the motion picture must still be cut so the movie can be projected on film in theaters. Therefore, the computer editing systems must work at exactly 24.00 frames per second, not 29.97 (in the case of NTSC video) or 25 frames per second (in the case of PAL video). Unfortunately, there is no video format which works at exactly 24.00 frames per second. This causes no end of problems. (Note: Cutting the negative is called "Conforming the Negative" so that it conforms to the edit done on the computer editing systems.)
- Telecine Dailies - Direct to Video Tape
- Even if a motion picture will be edited on video and release on DVD-Video disk, it must edited at approximately 24 frames per second, not 29.97 frames per second. All motion picture shot on film and released on NTSC DVD-Video disk in Hollywood are stored on the DVD-Video disk at 23.976 frames per second. Motion pictures on NTSC DVD-Video disk are never stored 29.97 frames per second. This is probably the most common misconception of beginning filmmakers. The reason is motion pictures stored at 24 frames per second can be much higher resolution than motion pictures shot on video at 29.97 frames per second since a motion picture at 24 frames per second contains fewer frames that must be compressed into the very limited bandwidth of a DVD-Video disk. (Actually, this is not a great problem until you add multiple audio track which also have to fit in the limited bandwidth of a DVD data stream.)
Telecine for Dailies
Today, video tape remains the cheapest and (ugh!) the most convenient method of storing dailies which have been telecined. Therefore, film editors have two choices when working with film dailies:
- 1. Do an Inverse Telecine
- One option is to telecine to video, then digitize all the frames, but finally do an inverse telecine to throw away the unwanted fields and frames so that your disk drive only holds actual film frames. In this case, there is a one-to-one relationship with the original film negative. This is a very clean solution... but most computer editing systems do not work this way.
- 2. Software Solution (such as CineTools)
- The other option is to telecine to video and then digitize all the frames (even the duplicate frames created during the telecine process) for storage on a hard drive. Then use a computer program to keep track of bad frames while you edit the motion picture so you only see the good frames and you never edit on a bad frame. This is wasteful and confusing but because video tapes are so cheap and disk drives are so expensive, most everyone uses this method.
NTSC Inverse Telecine
The inverse telecine process is the opposite of the telecine process (at least in theory). Inverse telecine is the process of taking video at 29.97 frames per second (59.94 fields per second) and converting them back to exactly 24.00 frames per second. In practice, most computer software will inverse telecine NTSC video back to 23.976 frames per second Computer programs such as Media Cleaner and Adobe AfterEffects have an inverse telecine feature. Actually, these programs only do half the job (remove the 3/2 pull down) and ignore the rest (specifically correcting the audio speed)... which most of the time is acceptable.
To repeat what is said above, telecine is really a two step process:
- 1. Slow down the projection of the film from 24.00 to 23.976 (24.00*1000/1001) frames per second.
- 2. Add extra fields and frames to convert 23.976 frames per second to 29.97 (30.00*1000/1001) frames per second for NTSC video.
Computer programs such as Media Cleaner and Adobe AfterEffects only reverse step 2, not step 1. In some cases, this does not matter. Here is an example:
- Wrong but Easy
- The Star Movie Shop creates editing workshops from dramatic scenes shot on 35mm film for film students to edit with Final Cut Pro at 24 frames per second on a Macintosh computer. After the dailies have been telecined, the dailies are delivered on either NTSC video tape or NTSC DVD-Video disks. First, Adobe AfterEffects is used to inverse telecine the footage from 29.97 frames per second (interlaced) to 23.976 frames per second (progressive). Then QuickTime Movie Player is used to compress the movie clips at 24.00 frames per second which means that occasionally (every 1000 frames), the program duplicates one frame to keep the audio in sync with the picture.
- Hopefully, you notice that this is not the correct way to do an inverse telecine. Using this method, any edit created using these dailies can never be matched back to the original negative. Because of the occasional duplicate frame, the frame numbers will be wrong. But for training film students, this is good enough.
- To do this correctly, the Star Movie Shop should change the speed of the audio from 23.976 frames per second to 24.000 frames per second as well as change the projection speed of the QuickTime movie clips from 23.976 to 24.000. Correcting the audio is not easy... so they don't. They just add duplicate frames instead. (Note: No one has ever complained!!!)
Amateur telecine of Super 8mm footage:
Here is a free way to telecine your Super 8mm footage for personal use. The method can also applied to other film gauges with the relevant equipment. It is based on the initial telecine method of shooting the projection screen. However, attention must be given to obtain good results. If you think that you just point and shoot, forget it! The result will be very disappointing. You have to do exactly as described, mainly calibrate the video camera correctly and eliminate flicker.
My father has a moderate collection of Super 8mm movies, either bought (mostly cartoons and B&W comedies) or shot back in the 80's with an amateur Canon Super 8mm sound camera. In the late 70's, early 80's when me and my sister were little, video was rare and expensive, at least in Greece, so our only source of entertainment was a black and white TV or cartoons on Super 8mm films. My father had bought quite a lot of these and made a good collection of Disney and Warner Bros classics. He had even spliced some of these in longer reels to keep us busy for more time. Of course he shot amateur films in every occasion (mostly at 18fps, which was similar to the LP mode in video-cameras), much like we shoot video today. Back in 1993, I decided to transfer all these memories to video for easier watching and sharing with friends. When I asked at our local photo lab I was astonished to hear a rather high price per 50ft reel (about 30€ which back in 1993 was much more valuable than today in 2006), and this was simply transferring the movies to a humble VHS tape, not any correction included, (and of course DV tapes and DVD didn't exist back in 1993)! Meanwhile, I had bought my Sony Handycam TR-805E Hi-8 camera that year which was the best (EISA Award for best camcorder 1992-1993), according to a popular Greek magazine called Hitech. Yes it had many features first seen in this particular model like optical steady shot, 400 lines resolution, manual controls etc. So I quickly decided to telecine the films myself, for free, using that camera. Of course I hadn't done it before, so first results were not satisfactory. But a tape can be re-recorded, so I tried again and again until I mastered the technique. So fellow amateurs don't worry! If you do EXACTLY what I describe below you will get good results, even with the first time!
1) Super 8mm (or whatever) film projector with variable projection speed.
2) Video-camera with manual exposure, focus, color balance and external mic in socket. Preferably a PAL version at 25fps which makes eliminating flicker easier (see below).
3) A good quality matte A4 white sheet of paper used as screen. Thick paper is better as it is easier to stretch it to keep it smooth.
4) Tripod to mount the camera.
5) A color monitor, preferably without overscan (so avoid a TV, use PC monitor if possible).
6) Headphones and other appropriate connection cables and adapters.
You could clean and lubricate your film if desired, and then you are ready to proceed...
Setup of the system:
The white A4 sheet of paper should be stuck on a wall. To avoid adhesive tape showing on the video you should use tape that sticks on both sides and put it at the back side of the paper. I use regular tape but create a little loop so it sticks both sides, and I place it at the back of each corner of the A4 paper. Thick paper is better. When you stick the paper make sure it is stretched and looks straight. If you have a smooth matte white wall you could use that instead. Avoid projection screens as they are not white and they are not smooth. Place the projector directly in front of the A4 paper or white wall. Make sure it is as centered to the screen as possible and doesn't project from an angle, either horizontal or vertical as this will give a distorted trapezoidal image! Mount your video-camera on the tripod and make sure it frames the A4 paper as centered as possible, again avoid any large angles which will distort the image. If your projector has sound editing capabilities, it should have a audio monitor output or external speakers output. Connect that with the camera's external microphone socket, using appropriate adapters if required. Don't load tape or disc to the camera yet. Most consumer cameras will switch off if not recording for several seconds. To avoid that simply don't load the tape/disc so it will stay on as long as it takes for you to calibrate your setup (see below). Connect the TV or computer monitor (via video or TV card) to assist framing etc. Connect headphones to the camera to assist sound setup (see below). Needless to say that the video-camera should be mains-powered to avoid switching off during the process! Don't load the projector with film yet...
Finding and locking the white balance:
Without film in the projector, project to the A4 paper. Use the zoom function (if applicable) to make the projected image as small as possible. This will help enhancing the video dynamic range (since the image will be as bright as it gets, we will set the exposure so as not to washout highlights and leave the camera cover darker tones as good as it can, see below). Adjust the projector if necessary so the white rectangle is projected at the center of the A4 paper. Frame the white rectangle with the camera, and zoom in enough to make sure that all the camera's sensor is filled with white. You may also deliberately blur the image a little (using the camera's focus control) to make white appear more uniform. Leave the camera to obtain the white balance automatically. After several seconds which ensure the camera has made up its mind on the white point, HOLD it using the appropriate control. This will ensure it is not affected by the scene lighting or color variations during recording. For cameras that allow manual white balance in small steps you could fine-tune it but rely on a good calibrated monitor for this, avoid the viewfinder or the camera monitor! I would suggest not to touch the white balance once locked. At this point bear in mind that some films (e.g., Disney cartoons) are color balanced for a Super 8mm projector's yellow light so they might appear a bit blue if balanced as above, but I personally don't mind as this can be fixed digitally later. If you are using a PC monitor, make sure it is well calibrated so your movie color and brightness appears correctly. Most monitors allow a "user color" setting. If you use that and set all three primary colors to the same value (e.g., 80% or 100%) you will almost always have correct white balance. The application used to watch the video image should have its color settings reset to default. Any errors can be corrected during editing later. I once had changed the color settings in the video application for another capture and I forgot to reset these to default, so the film image appeared bluer. When I tried to "correct" this altering the white balance from the camera, I resulted with yellowish video! So don't touch ANY controls once adjusted, especially from the camera! For B&W films you could enable the B&W or sepia effect (for cameras that support it), but I would rather record it as "color" to have a more realistic look (B&W effect would make it look more like B&W TV broadcast, rather than B&W film). So we have white balance fixed, let's proceed with...
Adjusting the focus:
At this point you have to load a short film in the projector. If you are quick enough you can do all of the rest calibrations before it runs out. While projecting on the A4 sheet, focus the projector as sharp as possible. Then zoom out and frame roughly the camera so it sees all the image and manually focus it. Leave focus to manual so it is not affected with scene changes. Using the monitor frame the camera as good as possible so you don't crop the projected image, but not let any annoying black areas either. If the aspect ratio doesn't match, then make sure you don't crop the horizontal dimension while centering the vertical dimension. Focus again if necessary. Bear in mind that if you change reels you may have to fine-tune focus of the projector. Also focus may be lost between spliced sections, if the splicing is not very good. If you use a computer monitor to avoid overscan, I suggest watching the video in a window so to assist perfect framing. If you only have a TV monitor you could zoom in by one or two steps to make sure there are no black areas around the projected image.
Adjusting the exposure:
While watching the image, manually adjust the camera exposure so it doesn't wash out light areas (highlights) and let camera cover darker areas as best as it can. This is because it is preferable to lose some information of the dark areas (which might not be that obvious) than wash out light areas which will be very annoying. Hopefully newer digital cameras will have greater dynamic range than my old analog Hi-8 had and should give better results. Let exposure to manual so it is not affected with lighting and scene changes. Hopefully the lighting will be the same for most of the movie, but in some amateur films there are differences notably between outdoor and indoor scenes. Don't worry some of it can be corrected digitally. Don't touch the exposure! Again, if you are using a PC monitor make sure is well calibrated for our dark working environment (brightness and contrast) and that the video application's color/brightness/contrast settings are reset to default. Due to gamma difference between TV/video and a PC monitor the image might appear a bit darker. This is normal, adjust the exposure as described above and don't worry. The same video played back on a TV monitor should look normal since it will have the correct gamma value.
The trickiest part, eliminating flicker:
To eliminate flicker, we have to match the projection frame rate with the camera frame rate. For PAL cameras this is relatively easy. We adjust the projection speed to 25fps for 24fps footage or to 16.66fps (50/3) for 18fps footage using a variable speed projector. Audio pitch difference is negligible and should not concern an amateur. A different approach is to adjust the shutter speed in cameras that support it. Mine doesn't so I cannot tell how good that works. I can tell that I was able to almost eliminate flicker by carefully adjusting the projection speed as described above. For NTSC users you could project at 20fps (60/3) for both 24fps or 18fps footage but the audio pitch difference might be very annoying, and not all variable speed projectors support that large variation of ±2 or ±4fps (my Chinon 9600 only supports ±1.5fps for example). I only have a PAL camera model, so I cannot tell how bad audio pitch difference sounds at 20fps. Later you could speed up or slow down the movie as appropriate to restore audio pitch, using a video editing software which supports this feature (eg Adobe Premiere). Of course you should rely on your monitor to eliminate flicker, not the camera viewfinder or built-in monitor! A CRT monitor is preferable since LCD monitors tend to hide flicker if it is small. Of course make sure the refresh rate (for CRT PC monitors) is set to highest possible for the used resolution, so as not to mistake monitor's flicker as film's flicker. Color depth should also be at least 16-bit or higher to assist color balance. Have in mind that when changing reels you may need to readjust the projection speed to eliminate flicker again. Also I am not sure if enabling the steady shot feature will help, but I do it anyway just to be on the safe side. Besides, since the video-camera is mains-powered we shouldn't worry about the higher power consumption. For new digital cameras that support it, you could try the 24fps setting (for 24fps films only), provided the image aspect ratio is not affected (in some models setting 24fps capture may also set 16:9 mode). Also enabling progressive mode (if supported) will improve image quality, regardless of the frame rate setting. Unfortunatelly my old analog Hi-8 camera doesn't support either of the two, so I don't know how much they help.
Adjusting the audio recording level for sound films:
It is recommended to use headphones for this as with speakers you may not notice much of the noise. Since we will be using the camera's external microphone input, it is usually boosted to improve reception, or in our case to distort sound! Using the headphones lower the volume a lot until you don't hear any distortion or the distortion is as small as it gets. Make sure the sound is heard as clear as it gets albeit if you cannot remove noise 100%. Usually a small noise is not audible in normal listening conditions through the TV loudspeakers. It only becomes audible in a very quiet environment or using headphones, so an amateur should not worry too much. Some video editing applications can also clean noisy soundtracks in some degree, if necessary, but again I wouldn't bother if noise is not audible in normal listening conditions.
What about my silent films?
If you have silent films I suggest that you set the projector to "silent" mode (if applicable) and switch off the internal camera microphone. Many will rush to say this is not possible with consumer cameras. Don't worry, here is a trick I have used: Connect a cable in the external microphone input but leave the other end unconnected. This will switch off the internal microphone in order to use the "external" one supposedly connected to the external microphone input. Always use your headphones to confirm no sound is recorded as a bad connection could record electronic noise and spoil the movie (unless you are willing to mute your TV set when watching your silent films). Don't forget to switch back to "Magnetic" or "Optical" mode for your sound films!
Ready to telecine your films?
Rewind the short reel you used to calibrate your setup. Load carefully the projector with the actual film you want to telecine, making sure you don't move the projector! Load carefully the tape or disc in the camera without moving it. If there is a remote control for the camera, it is a good idea to use it to avoid any accidental movement. Set the projection switch to THREAD (or similar) position and make sure the film leader is properly wound on the take up reel, even if it supposed to do that automatically, to avoid damage while projection. Do not thread it too much however, but keep it as far from the beginning of the movie as possible, so you won't miss the start! Switch off the projector. Turn off all lights to make sure stray light doesn't affect the projected image so the colors will look as vivid as it's possible (stray light reduces saturation and makes old films look even fader). If it is daytime darken the room as best as you can and use only a very small light (about 2 or 4 watts) away from the projection screen. It is recommended that all calibration is done in these final dark conditions for best results. When ready start projecting immediately and then start recording as fast as you can. If you don't mind leaving some blank seconds on the tape, you could start recording first, to make sure you won't miss the film start if the film leader is too short and the movie is almost starting. Fine-tune the focus of the projector carefully, if required, avoiding to blur the image. If you are familiar with your projector you should be able to know which way to turn the focus knob to avoid blurring the image accidentally. Wear your headphones for a few seconds, make sure sound is recorded as expected (I have had some bad experiences), or no sound is recorded at all for silent movies. When finished with one reel, rewind and change reels carefully without moving the projector. Refocus the new reel if required. Never leave the projector unattended as the picture may jump and you have to press the relevant release button briefly. If you fail to do so, the rest of your movie will be jumping and useless and you may damage the sprocket holes of the rest of the film. Don't even think about fixing a jumping movie digitally. It is virtually impossible. It is better to telecine that again. Other problem that I have seen is that the framing of the projector is lost and the upper or lower area of the picture shows the adjacent frame. This usually happens between spliced sections (not perfect splices) and can be corrected with the relevant knob which moves the projection gate vertically. Once familiar with the projector you should know which way to turn it to correct rather than pronounce the error. Usually the overscan feature of a TV will hide a small framing error, but I personally prefer to be as perfect as I can.
- If you want to digitally edit your video, of course you must first import it in a computer. When using a digital camera, video is already in digital form and is transferred as is to a computer (provided you use a DV cable, not analog cables!) or converted to other digital format (eg MPEG 2 for DVD authoring). So with the right software you can edit your footage in some degree. Remember that if the recording is not good enough you cannot do wonders, at least not with consumer level software.
- If you are using an analog camera (or a digital connected with analog cables for some reason), make sure film flicker is totally eliminated or as small as it gets. This is because when digitizing the video using consumer level cards (such as TV tuner cards) the flicker will most likely be pronounced. I have seen some of my early telecine attempts that they have only negligible and hardly visible flicker when watched on a TV, but too much when the same footage is digitized. This usually appears like the picture is perfectly exposed for a moment and then overexposed and washed out. This cycle repeats about every half second or faster while watching and it is very annoying. No matter what settings I chose to digitize that footage, I could not avoid this annoying effect. Thankfully newer TV tuner cards do not suffer that much as my old Matrox Rainbow Runner I used back in the 90's but the problem still exists! And don't forget that the best analog connection (that cameras support) is S-Video, so prefer that over the simpler composite output. Also if you use the dual RCA audio outputs, you should get better quality than the headphones output.
- Also for best results I recommend to capture the video (analog source) or convert it during transfer from the camera (digital source, DV connection) using the desired final resolution, such as 720x576 for DVD or 352x288 for Video-CD. Using larger resolution and then resizing could give better results but it takes more hard disk space and rendering time. If you don't want to make any corrections other than cut and merge, using the final desired resolution will make rendering times much shorter as scaling is time and resource consuming. Also make sure you capture (or convert for DV cameras) directly to the final desired format such as MPEG 2 for DVD, if your capture card/software allows. Of course you should capture at 25fps for PAL or 29.97fps for NTSC, to match the camera rate, NOT 24fps (unless video was shot at 24fps) or you will negate any flickering elimination efforts made!
- If you first capture to AVI or MOV/QT for MAC computers (usually M-JPEG compressed) and then convert to MPEG (as with older capture cards that didn't support MPEG capturing), will make editing easier (most programs work with AVI/MOV/QT rather than MPEG files) but will make rendering time larger (conversion between formats is time consuming). Also if you compress the video in one format (eg M-JPEG for AVI/MOV/QT capture) and then convert to another, the video is re-encoded, even for simple cut and merge functions, and quality degrades. This is also true for scaling, so use final specifications (format, resolution, color depth etc) directly. There are several programs to edit MPEG video, such as Pinnacle Studio and some freeware too (eg TMPGEnc, search on the internet with keywords such as "MPEG editing").
- During editing keep changes confined to the scene concerned (unless most of your film needs correction) to shorten rendering times and keep degradation from re-encoding to the minimum. A clever trick is to cut out the parts that need corrections or effects or titles, edit them separately and then merge them with the rest of the movie using references to the original video file for the unedited parts. If you do all of this keeping the SAME specifications, most programs will merge all the footage WITHOUT re-encoding (recompressing) the unedited parts, so there will be no degradation at all in the unedited parts (since basically their data will be copied directly from the original video file, rather than being processed)! This also saves much time since copying a digital file is much faster than creating it form start. (Processor only takes notice when starting to copy rather than being involved the whole time, whereas when creating the file all job is supervised by the processor).
- If you want to make a DIVX video or similar MPEG 4 format, avoid capturing directly to MPEG 4 format, since MPEG 4 compression on the fly is very CPU and memory demanding and you will most likely get a lot of compression artifacts. It is best to capture to high quality M-JPEG compression (AVI/MOV/QT) or MPEG 2 format and convert to DIVX later. When you have finished editing your film in the original format, render it as a video file of the original capture format using the same specifications to minimize compression artifacts, as explained above. Then convert the final rendered file to DIVX or similar MPEG 4 format using as large bitrate as you can (provided the final video fits on a CD if you want to save it on CD) and of course select the best possible quality setting (this in DIVX PRO 5 and above is called "insane quality"). Conversion utilities include QuickTime Pro (for MOV/QT files), VirtualDub and its variants (for M-JPEG AVI to DIVX AVI conversion), FlaskMPEG, XMPEG Pro (for MPEG to AVI DIVX conversion) DIVX PRO Encoder (for MPEG/AVI/MOV/QT to DIV/DIVX format or AVI/MOV/QT DIVX format) and many more. There is no need for dual or multi-pass encoding, if you set enough bitrate (at least above 700 Kbit/sec for 720x576) and best possible quality. As a novice guide, 700Kbit/sec video data rate and 96kbit/sec audio data rate will fit 2 hours of video in a 80min (700MB) CD-R disc. Keeping audio data rate at 96Kbit/sec, for up to 90 minutes use 960 Kbit/sec video data rate which will give far better quality. For up to 60 minutes use 1500Kbit/sec which will give excellent quality for standard definition video (720x576 for PAL, 720x480 for NTSC).
- For DVD Authoring you have to convert the final rendered video file in MPEG 2 (MPG/MPEG) if it is not already in this format (some consumer level DVD Authoring applications may also accept AVI/MOV/QT files, but it is not recommended as their rendering quality is usually inferior to that of a dedicated video editing application) and as for the bitrate, 5000 Kbit/sec is the minimum acceptable quality and will fit 2 hours in a standard (single layer) DVD disc, while 9500 Kbit/sec is the maximum DVD compatible (not all consumer grade programs support it) and will give about 1 hour of excellent quality on the same disc. Of course you can use anything between but don't forget to use the SAME settings from capturing, editing and to the final rendering to avoid unnecessary re-encoding and minimize compression artifacts. If you had set rather high bitrates and the final DVD files don't fit in a single layer DVD (about 4480MB), don't worry. You can use Nero Recode, DVD Shrink or similar utility to recompress it at exactly 4480MB. To minimise degradation use dual pass encoding (this in DVD Shrink is called Deep Analysis). This may take some more time, but for sizes about 75% to 100% of the original DVD folder size, you won't notice any difference.
- For DVD audio you can either use Dolby Digital 2.0 (Stereo) or MPEG Layer II format. I consider 192 Kbit/sec adequate, so you leave more space for video data on a DVD disc. Of course Dolby Digital 2.0 will give better sound than MPEG at the same bitrate since it is more efficiently compressed than the much older MPEG Layer II and it is compared to MP3 (MPEG Layer III) compression which at 192 Kbit/sec Stereo is almost CD quality. Of course the audio format for DVD compatibility is 48000Hz (48KHz) 16-bit per channel, and Stereo or Mono. Don't make the common mistake to capture at 44.1KHz (CD quality) because later you may experience audio sync problems when the DVD Authoring application may wrongly suppose audio is at 48Khz (DVD compatible)! Yes, I have seen this problem in consumer grade DVD Authoring applications, for example Sonic DVDIt. Fortunately most video capturing applications will force the correct settings if the DVD template is chosen.
- DVD Audio Note: Most consumer level video capture applications do not support audio capturing directly at Dolby Digital 2.0 format, even if the DVD template is chosen. Don't worry, you can capture audio at MPEG Layer II format and convert it to Dolby Digital 2.0 at the Authoring stage using a compatible DVD Authoring application, such as Pinnacle Studio Pro, DVDIt! etc (degradation in quality from conversion between audio formats is not gererally noticeable as it is when converting video from one format to another). For better quality you could try capturing at a higher rate (eg 256Kbit/sec or 384Kbit/sec) for MPEG sound and then select to encode sound to 192Kbit/sec Dolby Digital 2.0 in the Authoring application before proceeding with the rendering step. Don't forget the 48KHz setting, or you will most likely end up with audio sync problems which cannot be fixed!!! You will have to render the DVD data again, provided the original audio format is in 48KHz, otherwise you may have to capture the video again! So take care to avoid frustration! I cannot emphazise more the need to use correct settings for the intended final video format (eg DVD). And don't forget: Using the same settings (resolution, bitrare etc) from capturing to rendering will save you time and provide the best possible quality for the selected settings, based on your hardware and software used.
When calibrating your telecine setup as good as it gets, the results are amazingly good considering the method used, and best of all it is for FREE!
I hope that this amateur telecine guide was helpful. Good luck to anyone trying that. I know the video digitization section should be in another place in Wikipedia and Moviemaker Manual. Excuse me for this lengthy reference to video digitization, but I was trying to help novices.
By: Mr Sotirios Papakonstantinou, Greece, © 1993-2006. Feel free to distribute this text or link to this page, provided you state its source and my name.
Film Editing Software
Apple Computer develops Cinema Tools with Final Cut Pro. Final Cut Pro (and Cinema Tools) are purchased as part of Final Cut Studio. You use Cinema Tools to keep track of all the original frames for each piece of film before it was telecined into the computer. 'NOTE: Please explain the Cinema Tools process."
- 4k - 4,096 pixels across
- 2k - 2,048 pixels across
- 1k - 1,024 pixels across
- HD - 1920 x 1080 called also as 1080p or 1080i
- 1280 x 720 called also as 720p or 720i p = progressive, i = interlaced frame's
- PAL - 720 x 576
- NTSC - 720 x 480
It's unlikely that your telecine machine will be able to capture high resolution images in 'real time'. For example, most telecine machines can only do a 4k capture at about 6 frames per second.
In comparison, I had once read in a Super 8mm newsgroup that Kodachrome 40 (discontinued in 2005) had a resolution of approximately 2048x1536 (3 Megapixels). This was determined experimentally by a poster, and it means that if film had discrete pixels like digital video, Super 8mm Kodachrome could capture at 2048x1536 resolution (2K). Super8 mm film is snubbed by some professional filmmakers, who state that it can show limited detail (and a lot of grain) compared with larger formats. But even this humble format can show better definition than HD video (currently 1920x1080 maximum).
2- and 3-perf telecine
- Todd Ao in London will TK 2-perf
- Wikipedia's Telecine has a different view of the telecine process.