NTSC: Time calculation theory

[Alphaloop]

Well, I'm used to work with PAL sources, where no crazy floating point fps values occur. But now I have here a NTSC source to work with.

It's a VOB file with a video stream (NTSC 29.97 Interlaced) and one AC3 stream (Delay 0).

Now I have to cut 4050 frames from the beginning.

Am I right to say that theres momentarily no software that cuts these frames without reencoding the videostream and preserving the audio-video-alignment?

So I demux audio and video. I set the DVD2Avi project to feed into CCE and set the "Encode In" point to 4050. So far no problem.

What's the main issue: the realignment of my audio stream. I now have to take the cut value (4050) to calculate the amount of frames I have to input in AC3DelayCorrector to get the AC3 file in sync with the shorter video stream.




Now my question concerning the values.
My calculus is:

Video has 29.97 frames per second, means 1/29.97=0.0334 seconds per frame = 33.3667 ms per frame Am I right so far?
This with 4050 frames means I have cut 135135.135 ms from the beginning of the video stream. (?)
Now I have to load the AC3 into AC3DelayCorrector and input delay of 135135, which leads to a cut of 4223 frames = 135136 ms. (?)
Finally I mux video and audio with a delay of +1. (?)

Is this right, or do I have a flaw in reasoning?

Or is there a much easier way?

[SVCD4Me]

You can use VOBSplit from the downloads section to cut off part of a VOB. It calculates using bytes not frames, but maybe you can get it close enough?

http://www.doom9.org/Soft21/Vobtools/vobspl26.zip

edit: Can't you check the audio stream you want in DVD2AVI and have it split/demux it?

[Alphaloop]

Well, I now found Chopper XP, which seems to meet my needs quite close. Although it only allows cutting by a seconds marker, it's good enough, 'cause the cut point in my material has a three seconds blank moment. :)