There are a few methods for changing frame rate of an AVI file:
1) Just change the frame rate in the header from 24 fps to 30 fps. The video will run 25 percent faster, audio will not. So they will get out of sync. Playback will be smooth.
2) Duplicate every 4th frame and set the frame rate to 30 fps. Playback will show several small jerks every second.
3) Create 5 frames from every 4 by mixing a little of each frame together. Playback will be smoother than #2 but you may see double exposure like images.
4) Hard 3:2 pulldown.
AviFrate can do #1 in a few seconds. Just open the file, change the rate, and save. The original file is updated with the new frame rate.
VirtualDub can do #1 and #2 without reencoding.
For #1:
For #2:File -> Open Video File
Video -> Direct Stream Copy
Video -> Frame Rate... at the top of the dialog enable "Change Frame Rate To" and set the rate 30
File -> Save As AVI... a new file is created
AviSynth can do all four but you will be reencoding:File -> Open Video File
Video -> Direct Stream Copy
Video -> Frame Rate... in the middle of the dialog enable "Convert To FPS" and set the rate to 30
File -> Save As AVI... a new file is created
For #1:
For #2:AviSource("filename.avi)
AssumeFPS(30)
For #3:AviSource("filename.avi)
ChangeFPS(30)
For #4:AviSource("filename.avi)
ConvertFPS(30)
TMPGEnc Express will probably do #2 for AVI output.AviSource("filename.avi)
AssumeTFF()
ConvertToYUY2()
SeparateFields()
SelectEvery(8, 0,1,0, 3,2, 5,4,5, 6,7)
Weave()