Some strange video

[jagabo]

640x480 isn't a legal size for DVD. But if you author a DVD with that frame size it will play properly on many players.

[SameSelf]

For the video:
Decode into AVISynth.
Use "AssumeFPS(ntsc_video)" - slows down by 0.0999%, not noticeable now just need to slow down audio.

I just want make sure I understand the math correctly as I had to see for myself.

For example, if the original video was 30,000 frames encoded at 30000/1000 fps, then that would imply a timecode of 1000 seconds. If those 30,000 frames are kept and re-encoded at 30000/1001 fps, then the timecode is lengthened to 1001 seconds. Thus the video is now exactly 1 second longer than the original 1000 second timecode, or 0.1% longer, not 0.0999% longer.

% Change = Change in Time / Time of Original x 100% = 1 / 1000 x 100% = 0.1% longer (30p to 29.97p)

However, if the 30,000 frames were originally encoded at 30000/1001 fps and re-encoded at 30000/1000, then the timecode is shortened from 1001 seconds to 1000 seconds. And the video is 0.0999% shorter. So I believe this is where you are getting the 0.0999% from.

% Change = Change in Time / Time of Original x 100% = 1 / 1001 x 100% ~ 0.0999% shorter (29.97p to 30p)

IOW, the math is dependent upon which fps is the original timecode. Since my video was originally encoded at 30 fps and I am slowing it down to 29.97 fps, then it is 0.1% longer, not 0.0999% longer? Correct?

Summary (as I see it):
29.97 fps to 30 fps ~ 0.0999% shorter
30 fps to 29.97 fps = 0.1% longer