When is it harmful to deinterlace? When is it better to leave a picture interlaced? There are a few but important cases when deinterlacing can give you unsatisfactory results.
TV channels can air a music video clip interlaced and the next one non-interlaced. The same applies to commercials: One commercial is 25fps, the next one is 50fps. TV channels can air the news interlaced, but the intro to the news spinning globes etc is not interlaced.
The professional coverage of the 11th September attacks by the Saudi Arabian terrorists on the World Trade Center is aired progressively but the amateur footage of the events is aired 50fps. Vice versa a coverage may be 50fps, but changes to 25fps when old footage e. World War 2 films with Hitler is shown. A program may be 25fps, but the ending credits are 50fps.
A program may be 25fps, but a change from one scene to another may be interlaced see below.
Inverse Telecine with ffmpeg
A single frame can even consist of progressive parts and interlaced parts see below. Some channels air x which is always non-interlaced because heights below pixels cannot be interlaced as defined by international committees. Thus this can give you some problems if you deinterlace everything automatically or leave everything progressive. As you can see it's interlaced and has to be deinterlaced. The same music clip, the same scene, but different TV channel Belgium channel 'Zik.
Not interlaced, thus doesn't need to be deinterlaced. You'd lose quality if you deinterlaced it, though the quality loss wouldn't be high see belowbecause the deinterlacing methods described on this site are quite good. Side note: The next video music clip after this one, was interlaced again.
Quality loss after unnecessarily deinterlacing of progressive frames: Capture from a commercial for the new Volkswagen Phaeton. Magnified original non-interlaced The unnecessarily deinterlaced version.
As you can see only the moving part the high diver shows greater quality loss. Other details are nearly the same. Compare the eyelash. Some of the fine lines have stairs in them. Virtualdub's Deinterlacing method "Duplicate". Compare the fine hairs top and bottom and the letters. Virtualdub's Deinterlacing method "Discard" followed by "Bicubic Resize". Compare the hairs and letters.
Deinterlacing by blending: This is Deinterlacing by blending. Not only that a progressive frame can be motion blurred look at Jamiroquai's left hand in the second picture abovenow you also blend the next field into this one. So you really get a blurry result.The term is also used to refer to the equipment used in the post-production process. Initially, this allowed television broadcasters to produce programmes using film, usually 16mm stockbut transmit them in the same format, and quality, as other forms of television production.
Within the film industryit is also referred to as a TKbecause TC is already used to designate timecode. The opposite of a telecine is a kinescope. With the advent of popular broadcast televisionproducers realized they needed more than live television programming.
By turning to film-originated material, they would have access to the wealth of films made for the cinema in addition to recorded television programming on film that could be aired at different times. Originally the kinescope was used to record the image from a television display to film, synchronized to the TV scan rate.
This could then be re-played directly into a video camera for re-display. As the film was run at the same speed as the television, the flickering was eliminated. Various displays, including projectors for these "video rate films", slide projectors and film cameras were often combined into a " film chain ", allowing the broadcaster to cue up various forms of media and switch between them by moving a mirror or prism. Color was supported by using a multi-tube video camera, prisms, and filters to separate the original color signal and feed the red, green and blue to individual tubes.
However, this still left film shot at cinema frame rates as a problem.
The obvious solution is to simply speed up the film to match the television frame rates, but this, at least in the case of NTSCis rather obvious to the eye and ear.
This problem is not difficult to fix, however; the solution being to periodically play a selected frame twice. For NTSC, the difference in frame rates can be corrected by showing every fourth frame of film twice, although this does require the sound to be handled separately to avoid "skipping" effects.
A more convincing technique is to use " pulldown", discussed below, which turns every second frame of the film into three fields of video, which results in a much smoother display. PAL uses a similar system, " pulldown". However, during the analogue broadcasting period, the 24 frame per second film was shown at a slighly faster 25 frames per second rate, to match the PAL video signal.
This resulted in a fractionally higher audio soundtrack, and resulted in feature films having a slightly shorter duration, by being shown 1 frame per second faster. In recent decades, telecine has primarily been a film-to-storage process, as opposed to film-to-air.
Changes since the s have primarily been in terms of equipment and physical formats; the basic concept remains the same. Home movies originally on film may be transferred to video tape using this technique, and it is not uncommon to find telecined DVDs where the source was originally recorded on videotape.What is inverse telecine Nvidia?
Telecine simply refers to the process of recasting film video source for television broadcast. Inverse Telecine is simply the reverse of that going from higher frame rate down to 24 to evoke that "filmic" look, and Nvidia has some standard ways of accelerating that, which you can control. See Full Answer. What does it mean if a video is interlaced? Interlaced video is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured at two different times.
Flicker is a visible change in brightness between cycles displayed on video displays. It applies especially to the refresh interval on Cathode ray tube CRT televisions and computer monitors, as well as Plasma based computer screens and televisions.
Designed for the analog NTSC television system, interlaced scanning uses two fields to create a frame. One field contains all the odd lines in the image, the other contains all the even lines of the image.
A television scans 60 fields every second 30 odd and 30 even. Interlacing also known as interleaving is a method of encoding a bitmap image such that a person who has partially received it sees a degraded copy of the entire image.
What is VLC deinterlace? Jump to: navigation, search. Deinterlacing is the process of converting source material that contains alternating half-pictures to a computer screen that displays a full picture at a time.
What does TTF mean? TTF is an acronym, abbreviation or slang word that is explained above where the TTF definition is given. What does TFF mean? TFF is an acronym, abbreviation or slang word that is explained above where the TFF definition is given.
Capturing from VHS - Part 2 - Inverse Telecine
It is also called a Telecommunication Device for the Deaf TDD but that name has been devised by the hearing community and is not accepted by Deaf people, the actual users of TTY technology. They still prefer the term, TTY. A TTY can be used to send text over the phone. What is interlaced encoding? Interlaced Video Encoding. Video data intended for use with computers is typically progressive, meaning that each frame is encoded as a single image.
Some devices, like televisions, do not display a frame all at once, but as two images. One of the images, or fields, contains all of the even numbered rows. When a non- interlaced PNG downloads in a browser, it downloads the image in one pass - from start to finish. An interlaced PNG downloads as a whole image very quickly, but at low quality, on each successive pass it downloads more of the detail, until the complete image has downloaded.
What is inverse telecine do? Inverse Telecine is the process where video editing tools reverse telecine process. Inverse Telecine involves more than shifting fields from one frame to another.
What does reverse telecine mean? Reverse telecine is the opposite process of taking There are numerous ways to add pull down including which makes editing easier but the concept is the same.
What quality is telecine? However, the result is inferior since the source material is usually a lower quality copy reel. What is TC in movies?Create an account Login: Lost password. Inverse Telecine is the process where video editing tools reverse telecine process. Inverse Telecine involves more than shifting fields from one frame to another. Depending on the quality of the video, there may be significant differences in the two fields that make up a reconstructed frame, as well as between different copies of the same duplicated field.
In order to avoid as much post processing as possible and some will almost certainly be required it's important that pairs of fields that make the best matches are combined. This isn't generally too complicated for frames with no motion, but motion can cause the edges of objects to shift slightly from one field to the next.
Once fields are matched, you have an approximation of the original 24fps film, with additional frames inserted from the duplicate fields. Decimation Since the frames containing extra fields should now occur in a regular pattern, we remove them from the video, which is often referred to as decimation. After decimation we still don't have progressive frames though. We have pairs of interlaced fields, which will likely not line up perfectly. Because the encoder treated them as two separate pictures from two different moments in time, some corrections must be made to weave them together into a single picture.
Interlace Artifacts Artifacts are imperfections that occur as the result of the encoding or decoding process, compared to noise, which is caused by interference from an outside source.
Encoding film sources interlaced with a telecine pattern introduces combing artifacts. Combing refers to the jagged lines that result from the same object in two fields of the same frame not lining up correctly. This is fine for actual interlaced video, where each field is from a separate moment in time, but for film we want frames to represent individual pictures.
This is a much simpler process than deinterlacing, because no decisions have to be made about whether there's motion between two fields in the same frame, but can still result in low quality if the differences between fields are too great. GSpot is a nice little tool that allows you to see what codecs your video file uses in order to determine what you need to install on your system to watch it.
Home Glossary. Inverse Telecine Inverse Telecine is the process where video editing tools reverse telecine process. Glossary Select a term to see the explanation. File extensions Select a file extension to see its definition.
All rights reserved. AfterDawn is powered by. GSpot Freeware GSpot is a nice little tool that allows you to see what codecs your video file uses in order to determine what you need to install on your system to watch it.Deinterlacing is the process of converting source material that contains alternating half-pictures to a computer screen that displays a full picture at a time.
This is a fundamentally impossible process that must always produce some image degradation, since it ideally requires "temporal interpolation" which involves guessing the movement of every object in the image and applying motion correction to every object.
Traditional TVs do not display one picture-frame at a time. Instead, they display alternately all the odd lines and all the even lines of the picture. That way, they can get a fast display rate of 50 or 60 half-pictures per second, without the bandwidth requirements that full pictures have. Computers however, do display full pictures, typically at a rate of at least 60 pictures per second.
So to get optimum quality when displaying TV-material such as DVDs on a computer, the player can convert the alternating half-pictures to full pictures. That is called deinterlacing. Modern HDTVs operate much like computers in that they display full pictures. Much like computer-based video players, they have deinterlacing built in so that they can display traditional TV material.
A very good description of the problem and the various ways of deinterlacing can be found at fps. VLC media player has deinterlacing off by default. You can enable it for the currently playing video by using the main menus, the right-click menus or by using hotkey by default: D. It switches deinterlacing on and off using the mode selected in the Preferences.
To change the settings, go to the Video section in the Simple Preferences. You can choose from On, Automatic or Off. This setting controls whether VLC enables deinterlacing when you open a video.
You can also choose the mode algorithm. See below for available modes and mode recommendations. In the mode AutomaticVLC will check the stream flags technical term for information embedded in the video and automatically set deinterlacing on or off, depending on if the current video is marked as interlaced even in animated movies on DVDs.
However, the detection is not always reliable. If the setting is OnVLC will apply deinterlacing even if the original is not interlaced which is a really bad idea. The setting Offrespectively, always keeps deinterlacing off. The available settings are the mode algorithmand in v1. Note that if you enable deinterlacing from the menu, the setting will only take effect for the currently playing video.
If you want to always enable deinterlacing on every video, type "Deinterlace" in the Video Filter preferences. The keyboard shortcut to switch deinterlacing on and off can be configured in the Hotkeys section of the Simple Preferences. Its name is Cycle deinterlace modes. If you use VLC from the command line, you can also set the deinterlace options in your command. To get a list and short description of the available options, run. Note that the deinterlace command-line options are prefixed by "sout" for historical reasons only; they are intended for normal playback use.
The version control history git log says the following about the Automatic mode see [f96bcfba15ae0cb8ffe8] :. As such, it is not really reliable for 25fps at least. As soon as a picture is detected as interlaced, the configured deinterlace mode is applied.
After 30s of progressive video, the filter is removed. The hysteresis helps with unreliable interlaced flags.Compressing an interlaced video source is a waste of space. Thus, something has to be done. Besides that, you would save If you just deinterlace your video before compressing as I recommended in my previous article - sorry! All you would do is mixing both fields together. The result would look like this:. As you can see from the picture above, both images are still present.
I just got rid of the field lines. Besides, by doing this you lose half of your resolution, since the deinterlace process mixes the horizontal lines two by two. What it does? When set to "reconstruct from fields - adaptive", it "demixes" the fields of the frames, so that they will be exactly how they originally were, eliminating one frame in every block of five, giving you the final result of The frames would then look like this:.
Notice that no information of the original movie has been lost. It's all there as it should be, and you don't loose any resolution at all! Isn't this enough for you???
What if I say it's even faster than deinterlacing? Notice that if you are using "inverse telecine", you don't need to and you shouldn't use the deinterlace filter.
The "inverse telecine" does it all. Another important point is that you movie must have been captured at That means of horizontal lines. VirtualDub does it, although I strongly recommend "freeVCR", which is a freeware that can be downloaded from "www. DO NOT change the frame rate. Set the "interleave audio every" to 30 frames. Some further explanation about "inverse telecine" can be found in VirtualDub's help file. Your Rating: You have not voted yet! Average: 3.
Duplication of links or content is strictly prohibited. This website divx-digest. Facebook Twitter Newsletter YouTube. Even more: making the encoding time shorter!! A miracle? It is possible sometimes with a VirtualDub function that I forgot to mention in my first article see "Best resolution for capturing from a VHS source", by myself.
To be honest, I didn't forget to mention it. I just didn't know it existed. Well, living and learning! That "almost miraculous" resource is called "inverse telecine", and I'll be sharing this experience with you now.Mothers of The Disappeared - U2 Cover
Most of the movies you find in your "Blockbuster video store" are included in this category.Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. I'm trying to achieve a proper inverse telecine but I'm running on a linux environment and I don't want to hassle with avisynth. After a LOT of testing, this is the command that gives me the best results : Code:.
Soo for anyone interested, I've come back with 2 things : - For some kind of telecined content, ffmpeg will do a great job of IVTC with the following simple filters : Code:.
Last edited by Ely; 21st July at Tags i The time now is Proper IVTC using exclusively ffmpeg. User Name. Remember Me? Mark Forums Read. Thread Tools. After a LOT of testing, this is the command that gives me the best results : Code: ffmpeg -i input. I decided to go with mpdecimate instead of decimate because it gave me better and more consistent results. Find More Posts by Ely. Soo for anyone interested, I've come back with 2 things : - For some kind of telecined content, ffmpeg will do a great job of IVTC with the following simple filters : Code: ffmpeg -i input.