When should I de-interlace ?

[Iron Mike]

Hi,

I'm a newbie to encoding and I'm converting multiple '.vob' files into '.flv' files via 'Flash 9 CS3 Video Encoder'...

First of all I'm using 'Carbon Coder' to create an '.avi' file out of the '.vob' file (because Flash Video Encoder does not accept .vob files) and then I'm converting them to '.flv' files via the Flash Video Encoder 9 CS3 Pro.

Now there's an option under the 'video' setting to de-interlace...

I thought de-interlacing is always needed when I deal with interlaced files.

So I have this one file right here, here's the video info from MediaInfo:

Video #0
Codec : MPEG-2 Video
Codec profile : Main@Main
Codec settings/Matri : Custom
PlayTime : 5mn 34s
Bit rate : 8000 Kbps
Bit rate mode : CBR
Width : 720 pixels
Height : 480 pixels
Aspect ratio : 16/9
Frame rate : 29.970 fps
Standard : NTSC
Chroma : 4:2:0
Interlacement : Top Field First
Bits/(Pixel*Frame) : 0.772

As you can see, it says "Interlacement: Top Field First".

Now strange to me is, that when I convert with de-interlacing the quality is far worse than when converting without de-interlacing.

So here's my question:

When should I de-interlace video files and when not ?

As always, thanx for your help and advise in advance !

Mike

[Adub]

Okay, now I won't get into the whole nuts and bolts with it, you will have to do some research.

There is a difference between IVTC and deinterlacing. Check out the Avisynth forums for more information. Plus Doom9 has some good guides on the main website.

And if you really don't want to think, MeGUI has a detection algorithm in it that will do most, if not all of your work for you.
Check it out.

[neuron2]

When should I de-interlace video files and when not? You should consider deinterlacing when you have interlaced video (not pulled-down or phase-shifted progressive video) *and* you want to play it on a progressive display. But even there you have the option of leaving it interlaced and letting the TV or player software do the deinterlacing during playback.