[FFmpeg-user] How to deinterlace strange interlacing

Ulf Zibis Ulf.Zibis at CoSoCo.de
Thu Apr 15 16:34:38 EEST 2021

Hi Christoph,

Am 03.04.21 um 00:42 schrieb Christoph Gerstbauer:
> Hello, forget my last mail. The original video is destroyed in the first place.
> If you SPLIT the fields from the original MPG you see PER FIELD interlacing artefacts. That is a sign that the original video from tape was not correctly DEINTERLACED (25i-> 50p -> 25p) when going into MPG format.
> You see in the picture TOP field and Bottom field of the MPG file.
> Normally NO interlacing lines should be in one FIELD.
I was thinking about an algorithm, which could work as follows:

1. Extract all 2nd lines from a frame
2. Rebuild planes
3. Intelligently filter or move the stripes horizontally
4. Merge the planes or create a stream with double frame rate to create a visually better video.
I was in hope, that such algorithm exists somewhere

> See attached file.
> So I guess the way of the signal was:
> 1. ) TAPE (I guess betacam or imx): Interlaced top field first (25i)
> 2.) digitized into file as PROGRESSIVE 25fps without handling the interlacing. (25p)
> 3.) ENCODING to MPG with a bottomfield first flag, but already destroyed fields.... (25"i"/p)
Seems probable.
> This can not be repaired.

Thanks for your thoughts,


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