Resize/Upscale questions

[Selur]

For video captured with VC500 device, where is no PAR data in the header, would it make sense to set Input PAR 16:15, instead of 1150:1053 as I was going, since it is more close to 1.333 ratio, vs 1.366 using 1150:1053 and this is what Canopus has inserted?

Whether it makes more sense or not depends on whether it causes distortions or not.

One more:
If use/check Force Input PAR type, changing value to “ITU-601” (that should be the correct PAR for an analog capture as you said), Input PAR stays same as default 1:1, Target Resolution stays the same as well 904x720. Using Vapoursynth Preview, I see squeezed circle.

Why entering Forcing Input PAR to ITU-601 does not change PAR and Target resolution values, looks like it does not go in to effect?

PAR 1:1 does not change in any of the par type, what 'Force input PAR type' does is to change the interpretation of the found information.
see: https://forum.selur.net/showthread.php?tid=597
It does not miraculously know whether your source is 4:3 or 16:9.
He's an example on what it does:
Assuming your source if flagged as '12/11' which would normally mean MPEG-4 (PAR type) for PAL 4:3 content.
If you now set it to 'ITU-601' instead of '12/11' input PAR would be changed to '1150/1053'.

Cu Selur

Ps.: The PAR info Hybrid shows its what it can gather through mediainfo&ffmpeg if both of those tools find no par info 1:1 is assumed.