Interlaced ?

andy

I thought all movies where interlaced, just as a TV-picture.

Am I wrong here ?


Originally Posted by apfraatsI thought all movies where interlaced, just as a TV-picture.

Am I wrong here ?
ah, yep... All movies are non-interlaced (Mostly, some parts of movies can be Interlaced)

Yes... usually... DVDs (nowadays) are encoded as quotrogressivequot;.

Wait a moment. A tv-broadcast here is sending you 25 HZ frames, but the consist of two 50 hz interlaced scans. So the first scan scans all even lines and the second scan scans all uneven lines. This happens 50 times a second so 25 complete frames are send and received.

I thought playing a DVD would use the same principle ?

Or is the player converting this to a compatible image for the TV, which still functions interlaced ?

It all depends at what point of the presentation you look at it.  Often it will be progressive on the DVD -- but will be converted (or telecined if NTSC) into an interlaced format just before it is output to the TV.  If you have a TV capable of progressive input, however, it will play back progressive.

So if I get it right, it is progressive on the DVD (nowdays). So a frame is just build up of lines following up each other.

I'm in Eurpoe and have noticed progressive output on one my DVD-player and on my HDD-DVD recorder.

I'm just having a television-set with typical Eurpean input RGB SCART, probably not progressive.

Wat are the advantages of progresive scan, above 100 HZ interlaced ?

Clearer picture, smoother action... lots of other benefits.

Just to be clear, there are lots of DVDs with interlaced input on it too.  MPEG-2 handles both.   Most are progressive, though.

If you have a progressive display what is it framew rate.

Interlaced was being invented to prevent flickering at 25 HZ (although it still does) by interlacing the two 50 hz frames.

If a progressive display results in lines projected one after the other, the rate should be 25 Hz, or is it still 50 hz and displaying one line after the other or even higher ?

Interlaced was created out of necessity due to the limited persistence of phospher dots that were used combined with attempting to build a system based on the 50Hz/60Hz frequency of the electrical system.  But that was over 70 years ago and things have changed a lot since then.

A progressive output would send a complete picture 50 (or 60 for NTSC) times a second -- but, don't let that fool you.  Because the source of the picture (the DVD) still only has 25 unique pictures for every second of video... I'm sure there is some method of interpolation for the extra frames -- but I don't think I've ever actually delved into it.