Speed dating movie clips
So interlacing is in fact a clever way to compress a movie when one cannot use digital compression methods.Interlacing reduces the bandwidth (= storage space nowadays) by half, without losing vertical resolution in quiet areas (in motion areas you don't notice very much anyway, because it's moving 50 times per second).
In other words: A single frame consist of 2 captures of 2 different moments in time. Scene1 Scene2 (This is Britney Spear's performance at the MTV Video Music Awards 2001) On a computer screen interlaced recordings are annoying to watch because the lines are really disturbing.Example: There are 2 kinds of DVDs: Some have an interlaced format (like the examples above) and some are transferred from film to DVD directly, thus have 25 progressive frames encoded. Since TV sets expect you to feed them with 50 images per seconds (whether it's from your old analog VHS recorder or from your antenna or from your DVD player) the DVD player needs to convert those 25 progressive frames to 50 images and send them to the TV set.That means they have to get interlaced them (well, it's not interlacing in its original sense, but you are making 50 images out of 25 images) instead of letting the TV simply display those original 25 fps.Just recently Panasonic introduced one of the first TV sets to be able to receive progressive frames from the DVD player.So you need 2 things: A special DVD player, that suppresses the 25p- Because it's 1930s technology.You also have to know that Field1 is Position1 (higher) and Field2 is Position2 (lower).
Both field1 and field2 combined together give you the full vertical (top to bottom) resolution.
The main reason for this: Movies with 25 non-interlaced (=progressive) frames per second don't look very fluid.
If you watched a football game with 25 progressive fps it would look as if the ball isn't flying fluidly thru the air.
Interlaced Frame=Field1 Field2 as you can see clearly.
But even after deinterlacing some red and some green pixels stay where the last field was. Maybe this clip was recorded interlaced and was then transformed to be progressive and these are the left deinterlacing artefacts. Unfortunately this is the way digital camcorders and digital VCRs record and digital broadcasting is done.
This site shows you how to make brilliant looking Div X video (from TV, DVB, DV, DVD etc) for archiving purposes OR how to reduce file size to produce good-looking yet small Div X footage. Note: The timeline of your analog camcorder is usually different.