Scaling down h264 video for joining with another h264 video

[JamNujo]

I have included in this post 2 samples of the videos I am attempting to join together. The second video needs to be downscaled to match the resolution of the first video. I tried my best to find the right settings in handbrake to make the second video compatible for merging with the first one, but it just won't work. The image of the second video gets corrupted (blocky colors) once merged with the first one. The same happened when reencoding the second video with ffmpeg.

Help is appreciated.

https://files.videohelp.com/u/289660/Test01.mp4
https://files.videohelp.com/u/289660/Test02.mp4

[davexnet]

This can be difficult, perhaps it's best to re-encode both. I used a simple avisynth script and re-encoded in Virtualdub2

LoadCPlugin("C:\your_Path\ffms2.dll")
aa=directshowsource("C:\Users\davex\Desktop\test01.mp4",video=no).SSRC(48000)
av = FFVideoSource("C:\Users\davex\Desktop\Test01.mp4", track=-1, fpsnum=60, fpsden=1, seekmode=0)
#
ba=directshowsource("C:\Users\davex\Desktop\test02.mp4",video=no)
bv = FFVideoSource("C:\Users\davex\Desktop\Test02.mp4", track=-1, fpsnum=60, fpsden=1, seekmode=0).spline36resize(1280,720)
a=audiodub(av,aa)
b=audiodub(bv,ba)
return a+b