Inverse Telecine

IVTC (Inverse Telecine) is a proces that takes interlaced video with a telecine pattern and attempts to re-create the film frames it was generated from. Depending largely on the quality of the analog capture this can be very effective. The operation will be performed in an AviSynth script we'll write using AvsP. You should be starting with a script that already has the line to load your source. You'll also need to have TIVTC.dll copied to your AviSynth plugins directory. If you don't know how to do that, you can find instructions for AviSynth plugins in our AviSynth guide. Although that guide utilizes a different tool (AVSEdit) than we'll be using (AvsP) to write scripts with, it does explain the basics of AviSynth plugins and using them.

Field Matching

There are two basic processes required for IVTC. The first is field matching. A telecine pattern leaves you with fields from the same frame stored in different frames. Field matching needs to determine which fields should be combined into a single frame. When there are multiple copies of the same field it's also good to determine which one will create the fewest artifacts when combined with its match. Interlaced encoding will give you fields that don't look the same as if they were encoded together as a single frame. It may be good to add some deinterlacing techniques to the end of the process.

Decimation

After fields are matched, the excess fields need to be dropped. This is called decimation.

AviSynth Commands

Just like there are two different processes involved in IVTC, there are two different commands to add as well. Field matching is assisted by access to the D2V (DGIndex Project) file. It can be referenced using this line:

tfm(d2v="D:\Storage 3\Basic DVD Project\Cartoons\Destruction Inc.d2v")

Decimation is done with this filter:

tdecimate()

Placement In Your Script

For best results IVTC should always be performed as soon after loading the file as possible so fields aren't changed, making field matching harder. Decimation should follow immediately after field matching to make sure any later filters are seeing the actual film frames with nothing extra. You can even add them as a single line by following the field matching line with a . and the decimation line:

tfm(d2v="D:\Storage 3\Basic DVD Project\Cartoons\Destruction Inc.d2v").tdecimate()