Telecine/Interlaced...am I wrong?

[oscdude]

OK correct me if I am wrong.
Telecine is another word for Inverse Telecine (IVTC)
A NTSC video in 30fps telecined from 24fps can be converted back to 24fps with IVTC.

How do I know if the video has been Telecined? I look at the frames and if I get 3 progressive frames followed with 2 interlaced frames then its Telecined.

Now, I capture NTSC music videos to be viewed on PC only. Now if a video was telecined then its better for me to perform IVTC and adding a pulldown when playback to get rid of the nasty interlacing. Right?
To do that I use avisynth with the following commands:

LoadPlugin("MPEG2DEC.dll")
LoadPlugin("decomb.dll")
AVISource("video.avi")
Telecide()
Decimate(cycle=5)
LanczosResize(480,480)
TemporalSmoother()

Is this correct?

Now, there are times when the source is all interlaced..so I then must apply deinterlacing instead of IVTC.
And to deinterlace I use:

LoadPlugin("MPEG2DEC.dll")
LoadPlugin("decomb.dll")
AVISource("video.avi")
FieldDeinterlace()
LanczosResize(480,480)
TemporalSmoother()

Is this correct and is there a better way to deinterlace?

Thanks!

[adam]

For the most part, yes that is all correct.

Telecine is not the same thing as IVTC, but I don't think you really meant it like that. Telecine is actually the process of converting film to a regional format, so it also includes FILM->PAL but when we talk of telecining we mostly mean FILM->NTSC. Such a telecine involves breaking the frames into fields and then repeating those fields in a specific pattern to increase the framerate to the desired speed, ie: 29.97fps. So IVTC is just the decimation of these repeated fields and the recombining of the remaining fields back into progressive frames. Basically the processes are opposites of each other.

Now there are lots of telecining patterns, and sometimes they actually combine patterns but a 2:3 telecine is by far the most common one. To see the pattern that your footage has undergone then yes, you should just look at the fields in something like TMPGenc and compare the number of progressive to interlaced frames and then IVTC accordingly. If your source has undergone a 2:3 telecine then the avs script you posted is the correct method to IVTC. For other patterns you will have to make adjustments to your script, and the documentation for decomb will go into more detail on this.

If you are encoding solely for pc playback than you actually should not add the pulldown flags, but instead just leave it 23.976fps progressive. PC's do not require regional format compliance, and adding the flags will only force some software players to telecine to 29.97fps and then deinterlace on the fly. Pulldown flags only need to be added if you intend to watch this on a tv.

Other than that your scripts and your methods look great.