VirtualDub Deinterlace question

[weaver4]

I have a DVD that I am trying to convert to XviD for my media server. The orignal framerate is 30fps. When I do his with avi.net or autogk the fps are changed to 23. But when I use vd with the MPEG4 plugin my video is still 30 fps. The filters that I am using in order are:

deinterlace // set to default values
null // used to crop
resize // used to resize to 640x272

What am I doing wrong that I am not getting a deinterlaced video at 23 fps?

Thanks.

[Blue_MiSfit]

You need to understand the difference between deinterlacing and inverse telecine.

Deinterlacing applies to true video footage - I.E. video or live TV etc... This is actually 29.97fps interlaced (therefore 59.94 half resolution pictures per second). Encoding this stuff for display on a progressive scan monitor (your PC) necessitates deinterlacing to return 29.97 (progressive) fps.

Inverse telecine applies to film footage. Basically, films are shot at 24 (progressive) fps, and to make this 24fps fit in the NTSC standard 29.97 (interlaced) fps, studios perform a process called telecine (or pulldown), which duplicates fields to make 24p fit in 29.97i.

This process (if done in a smart way) is lossless, and the original 24p can be recovered without any damage.

Most of the time for Hollywood movies you can do the lossless method - and it's called Force Film in DGIndex. Sometimes you can't use force film and you have to use a manual IVTC filter through VirtualDub or (preferably) AviSynth.

AutoGK and Avi.net are likely (correctly) detecting your source material is film at 23.976p fps inside NTSC 29.97i fps, and applies force film with DGIndex to recover 24p in a lossless way.

So - what can you do, if you want to do encodes manually in Virtualdub? Use DGIndex, and set force film when appropriate. Save the D2V and make a really simple avisynth script like

MPEG2Source("C:\video.d2v")


Load that sucker up in VirtualDub and you should have a perfect 23.976fps video without any problems.

~MiSfit

[weaver4]

Thanks for your help.

Since I am using the MPEG2 plugin to read vob files directly is there a IVTC filter that will run in VirtualDub.

[Adub]

Video -> Framerate -> Inverse Telecine

Personally, I would recommend IVTCing in Avisynth, as it provides better support for crazy, messed up sources that were telecined incorrectly and so on.