Crop only a part of a video possible?

[Platos]

I have one Video, which contains basically 2 Videos. The first 10 mins are 16:9 and it has very big black bars around (not only left and right. the whole video is surrounded from black bars). But the second half of 10 mins are fine and in 4:3. It can't be cropped or stretched.

Is there a way, how i can crop the black bars away from the first half?

I tried to cut the video with avidemux. First it did nor work, i could not cut on exactly that frame, but then i did it with a lossless reencode. It worked. Then i tried to insert it in Davinci Resolve, but in Davinci the frames looked completly unusable (it was only artefact-mud). But i could watch the video with no problems in media player.

And i did not find any free programm, where i can combine two videos with different resolution (but im not sure, if i should upscale it before or after connecting together).

But has someone an idea, how i can do that ?

I tried btw. auto-crop in hybrid, but it did not work. While it did crop the first half of the video, the second half of it did not work anymore after autocrop.

[jagabo]

Why don't you just use AviSynth to do the cropping and resizing. Then encode with whatever program you want (ffmpeg, x264 cli, x265 cli, MeGUI, etc.).

Something along the lines of:

WhateverSource("filename.ext")
part1 = Trim(0, 10000) # first part
part2 = Trim(10001, 0) # second part

part1 = part1.Crop(x,y,w,h).Spline36Resize(part2.width, part2.height)

part1++part2