Interlaced video divides a frame into even filed and odd filed to display while progressive video displays the entire frame at once. Interlacing provides full vertical detail with the same bandwidth that would be required for a full progressive scan, but with twice the perceived frame rate and refresh rate.
Well, interlaced vs progressive: which is better scan type? When cost and complexity are factored out, progressive is the better scan type because it reduces flicker and artifacts and provides clearer image. Although progressive scan is better than interlaced scan and most modern displays use progressive scan, interlaced technique is still used.
In this case, a process called deinterlacing is required. It converts interlaced signal to progressive scan. Do you have some interlaced videos or interlaced DVDs that need to be converted to progressive format?
We'll show you how to do this. She's seasoned at offering video audio conversion workarounds and always passionate about new trends, from hot HEVC, 4K to the new AV1 codec. Digiarty Software is a leading multimedia software provider, delivering easy-to-use and innovative multimedia solutions to users all over the world. Free Download for Win 7 or later. What's the Difference Between Interlaced and Progressive Scan You must have noticed that a video resolution is followed by a letter "i" or "p", such as i and p.
Table of Contents Part 1. What Is Interlaced Scan? Part 2. What Is Progressive Scan? Part 3. Newsletter Stay up-to-date with our news, updates, guides. A lot of analogue cameras, for example, are setup to deliver video in an interlaced manner. Even some modern digital cameras still offer interlaced mode. One method to tell if your camera was setup for interlaced content or not is in the specs.
While some will be overt, describing that the camera outputs in interlaced mode, others will state it in their mentioned resolution. For example, we already discussed that p is an HD feed that is progressive. Chances are good that someone has seen p content much more frequently than the interlaced version.
Most modern analogue cameras, if they are interlaced, should mention it either directly or with the resolution. Thankfully, there is a process called deinterlacing which can solve issues created from presenting interlaced content in a progressive medium. Deinterlacing uses every other line from one field and interpolates new in-between lines without tearing, applying an algorithm to minimize the resulting artifacts.
Deinterlacing is done at the encoder level for live content. How this is done varies from encoder to encoder, with some enabling it through a simple check box. From this screen you can select your source, with most having two options available.
Teradek encoder products, such as the Cube and VidiU, offer built-in hardware based deinterlacing. Inside the interface for the encoder, this feature is found under Encoder Settings.
Located above Adaptive Framerate , this feature is called simply Deinterlacer and can be enabled or disabled. For vMix, the user has to click Add Input in the left corner to open the input selection panel. The options present will depend on the type of source selected.
If selecting a source like a camera, an option called Interlaced should be present, located below Frame Rate. Unlike other encoders, to deinterlace content this option needs to be unchecked. Sometimes referred to as a pulldown, three-two pull down is a process used to convert material from film to an interlaced NTSC display rate. This involves taking content created at 24 frames per second and converting it to This process involves duplicating fields, two from one frame and then three from the next frame or the process can also be vice-a-versa.
Also known as inverse telecine IVTC , reverse telecine is a process that can be used to remove the effects of taking a source and stretching it from 24 frames per second to This involves removing the added information from the frames to return it to the 24 frames per second. For example, frame 1 might be converted into frame 1A and frame 1B through interlacing, with each being a vertical odd or even sequence that is interlaced.
However, frame 2 might be converted into frame 2A, frame 2B and frame 2C, with the last one being duplicated content that is used to gradually increase the frame rate. As part of reverse telecine, this added content would be removed to restore the video to its original frame rate.
Yes, if the source is not interlaced than the result can introduce needless artifacting if the deinterlacing methods are inadequate. This will be most noticeable on motion, which will have a greater loss of quality. Fine, rounded details can also suffer, often converting a smooth look into a blocky look, like mini stairs as would be common in video games with pixels present and trying to create curves.
If the type of deinterlacing being provided is blended, it can show obvious motion in the same frame. In addition, deinterlacing is more CPU intensive.
So an encoder using deinterlacing will require to be on a better unit compared to a similar encoder not using deinterlacing. So if a source is not interlaced, do not provide deinterlacing to it. After some sort of motion occurs in the feed it should be easy to tell if the source needs to be deinterlaced or not. Interlaced content displayed in a progressive manner is much more disruptive to the viewing experience compared to artifacts introduced from inadequate deinterlacing on already progressive content.
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