Как из NTSC восстановить PAL? Как проделать IVTC?

Basic concepts:
Soft telecine - the stream is encoded at 24 fps and the pulldown is applied during playback.
Hard telecine - your source was telecined before being encoded on the DVD (or before airing).
Double hard telecine - your source has at least one of the "intra-frame variable framerate" situations and the telecining was applied separately on each part of the frame, so the pattern is not constant and many frames are interlaced.
Field blended norm-conversion - Instead of going back to 24fps (film rate), the video streams are directly converted from NTSC (29.97fps) to PAL (25fps) or vice versa, creating ugly fieldblending (looks like DHT when inspecting a frame).
Hybrid - mix of 24t (24 fps displayed at 30 through telecining) and 30p (progressive movement on every frame)
Truly interlaced - each frame contains half the information of two frames, which means that you can bob it to 60p and see movement on every single frame, without any interlacing or blending.
Progressive - No interlacing whatsoever at the full framerate.
3:2 pattern - This pattern repeats itself from the very beginning to the very end of your clip: 3 progressive frames followed by 2 interlaced ones.
VFR - Variable Frame Rate - The sections of the clip run at different framerates, thus allowing to have less frames for the same movement. The duplicates are removed and played during the same amount of time as if there was the original amount of frames.
Lossless rendering pass - Save the file as uncompressed YV12 or Lagarith to apply the script only once and make subsequent filtering/encoding faster. It takes a lot of disk space: around 5GB for a 22 minutes clip @ 23.976fps with Lagarith and 20GB with uncompressed YV12.
Examples:
Double hard telecine - At first, your source may look like a typical Hard Telecined one, but after a more thorough inspection, you'll see that it's actually a DHT one: same source, different high motion scene.
Interlaced on top of telecined (can be hard or double hard) - In this case, it was a hard telecined source. Image
Obviously, since there's no pattern in DHT and interlacing on every frame with pure interlaced material, regular IVTC will output blends and jerkiness.
Possible situations:
For all these cases, you must load a d2v created with "honor pulldown flags" (DGIndex) in avisynth and check frame by frame with vdub, vdubmod or avsp.
The identification of the type of your source if of the utmost importance, because a bad evaluation of the problem will lead to other ones, such as blends and jerkiness.
1 - DGIndex tells you "100% Film" and you see a 3:2 pattern.
2 - DGIndex tells you "100% Film" and you see progressive and interlaced frames with no specific pattern.
3 - DGIndex tells you "something else than 100% Film" and you see a 3:2 pattern.
4 - DGIndex tells you "100% Video (NTSC or PAL)" and you see progressive and interlaced frames with no specific pattern.
5 - DGIndex tells you "100% Video (NTSC)" and you see a 3:2 pattern + the credits are truly interlaced and/or progressive.
6 - DGIndex tells you "100% Video (NTSC or PAL)" and you see progressive and interlaced frames with no specific pattern + the credits are truly interlaced and/or progressive.
7 - DGIndex gives you a percentage of Film or Video from 50 to 95% and you see a 3:2 pattern + progressive sequences (not only the credits, but the whole frame is).
8 - DGIndex gives you a percentage of Film or Video from 50 to 100% and you see a 3:2 pattern + progressive sequences (not only the credits, but the whole frame is) + the credits are truly interlaced and/or progressive.
Source type:
1 - Soft telecined, so your stream can easily be extracted at the film rate
2 - Double hard telecined encoded as progressive
3 - Hard telecined
4 - Double hard telecined
5 - Hard telecined + interlaced or progressive credits on top of it
6 - Double hard telecined + interlaced or progressive credits on top of it
7 - Hybrid
8 - Hybrid + interlaced or progressive credits on top of it
Solutions:
1 - You are happy! :p Use "Force film" in DGIndex and IVTCing/Deinterlacing/Deblending doesn't concern you anymore!
2-8 - You are also happy (maybe less since you have to work a bit more) because the problem can be solved! Read the following to learn how to use AnimeIVTC.