How would I know if the particular footage needs Inverse Telecine (IVTC) or not?
There is a detailed explanation on wikipedia.
(“Telecine” and “pull-down” are originally two different words, but are generally used interchangeably.)
The process diagram will help you get an idea of how the conversion between 24p and 30i is done.
To determine whether or not a video is a pulled-down video, feed the video frame by frame in the video editor.
If it looks like “A,” “B,” “B+C,” “C+D,” or “D,” then it is most likely video being pull-down.
Or is it that the VLC information regarding the source file may be incorrect? Could it be the case of a “later DVD recorded in 24p”?
Please read “Soft and hard telecine” on the “Telecine” page.
Older or lower quality DVDs may be recorded in hard telecine (30i), while newer or better quality DVDs are recorded in soft telecine (24p → 30i decoding).
Some players may recognize soft telecine as 30i.
I tried to display the information in Mediainfo and VLC for videos encoded with Soft Telecine.
A further question: if I end up with a 59.940 fps video (movie) after the processing, is there anything wrong with it?
The image quality is reduced because the original resolution is low and the amount of information is low.
720x480 30i (29.97 fps) is like 720x240 at 59.94 fps.
It is smooth as movement, but the amount of information as a picture is half the resolution.
For telecine video, inverse telecine is performed to 720x480 24p to obtain the appropriate amount of information.
