Thanks for the suggestions everyone.
And you're all probably right that I should abandon the idea of having it split [yes, I'm going to make it 60fps all the way through because it will be ~the same file size like both Zarxrax, and Wheee_It's_Me! suggested

]
But now I'm curious as to how to do it-- say I had 2 varying sources I wanted to combine, that I didn't want to re-encode. [*cough* my 30fps beginning and 60fps ending]
Scintilla and Wheee_It's_Me! suggested Matroska.
The only program I've tried thus far with Matroska export is vdub,
but not surprisingly, when I write:
avisource("30fps.avi", "60fps.avi") it fails to open
and directshowsource("30fps.avi", "60fps.avi") says only 1 filename is supported
Three thoughts come to mind:
1.can I add a parameter... something along the lines of:
Code: Select all
avisource("30fps.avi", fps=60, "60fps.avi")
[I know the syntax is wrong

]
2.can I get a directshowsource that supports 2 filenames?
3.another program
How would it be done? [disregarding compatibility issues]