How to change framerate correctely?

[papcom]

I have a progressive Videofile with 25 FPS. This video I want to export 1:1 but in order that it plays with 18 fps. The video itself must stay with 25fps but the content must play with 18fps.

How is the corrcet way to do this in Virtual Dub?

I do not understand the dialogue in Virtual Dubregarding Source Rate adjustment and Frame Rate conversion. especially the field "convert to fps"

[Groucho2004]

The video itself must stay with 25fps but the content must play with 18fps.
I think I know what you want to achieve but this part:
"The video itself must stay with 25fps"
makes no sense.
When you multiplex an elementary stream into a container, you set the playback rate, in your case to 18 fps. Your media player will then play it back at this rate.

[turbojet]

If you require 25 fps because of DVD/BD standards you should try dgpulldown. Otherwise encoding to 18 fps should play in all other cases.

[Groucho2004]

Otherwise encoding to 18 fps should play in all other cases.
I don't think he wants to re-encode:
This video I want to export 1:1

[papcom]

If you require 25 fps because of DVD/BD standards you should try dgpulldown. Otherwise encoding to 18 fps should play in all other cases.
As a result I need a 25fps videofile which plays the content with 18 fps. In a simple process this is normally done by doubling some frames in order that a total of 7 frames per sec. are added. Other more sophisticated tools calculate inbetween frames to achive an optical flow. - I thought that Virtual Dub is capable to do so.

BTW - I do not work with Mpeg as a master, and as far as I know DGPULLDOWN is for mpeg files.

[movmasty]

Video>framerate>change framerate to(fps) 18

then below
Framerate conversion>convert to fps 25