Do you manually select "23.976" fps or IVTC?

[agent2099]

Which is the preferred method to use when dealing with 29fps NTSC content.

I generally just manually set the fps down to 23, and therefore I don't check the IVTC tab (which is not even available when you choose 23fps). The benefit to this seems to be you get a higher bitrate since GKnot is able to know ahead of time that you are decreasing the fps.

Is this the preferred method, or are there benefits of using ITVC instead of just changing the framerate?

[jggimi]

I'm not exactly sure what you're doing. If you mean, when you do an IVTC in Gknot (actually, in the .avs script), should you check the box labelled "IVTC in avs -> ... " or not?

I used to just adjust the framerate manually. I no longer do so, as Gknot will have no way of making adjustments for end-credit start point. If you encode your end-credits separately, I recommend leaving it at 29.97 in the main Gknot window, and checking the box.

There's lots more info in http://www.doom9.org/ivtc-tut.htm

[agent2099]

Yeah you got the idea.


Either:

A. Adjust the fps to 23. The ITVC checkbox is no longer available.


B. Leave it at 29fps, and check the Box that says IVTC.


So far I have been doing A, since, I get a higher bitrate in the preview window.


However, evey time I do "A", the file size is usually about 150mb too small. I adjust by setting the CD size to 800mb instead of 700mb.

The end result is usually at 640-650mb file.

I guess, later on down the line, as I get more expeienced I'll be able to estimate it to be closer to 700mb. For example if I up the bitrate to 160 or 192kbps .mp3, it'll probably get me closer to 700mb. Thus getting the max quality video and audio for a 700mb cd.

[Hiro2k]

have you tried using option B?
The bitrate that Gknot shows is not what it will use since framerate will change to 23 fps after the IVTC. My advice is to use the 23 fps to find the right % of the film, then set it back to 29 fps and then encode the movie with the button checked to calculate the correct frame count of the movie. Im not sure if this is correct but that might fix the problem with your file size being short.