[HELP] PAL VHS source - cropping and PAR

[Miranda]

What would be the best settings to crop the left and right black bars from an old 4x3 PAL VHS recording (and the bottom tracking), and then re-size the pixel aspect ratio to square? Would I need to re-size to 768×576?

I have tried the auto cropping option but it will not crop the black bars.

[Selur]

a. Naturally autocrop will not crop those bars since they are not completely dark.
b. Yes, if you want to resize to archive PAR 1:1 you need to resize, but Hybrid will calculate the resize values.

[Miranda]

What would be the best way to do this?

[Selur]

No clue what's the best way.
Here's how I would do it in Hybrid:

• load your source
  
• start "Filtering->Vapoursynth->Vapoursynth preview" and scroll to a scene where you can properly see the bars (to have a live view of what you are doing)
  
• enable "Crop/Resize->Base->Picture Crop" and adjust the cropping so you get rid of all you want to crop
  
• enable "Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Cronvert output to PAR"
  
• set "Crop/Resize->Base->Pixel Aspect Ratio (PAR)->Cronvert output to PAR" to "Square Pixel (1:1)"
  Hybrid will then automatically activate ("Crop/Resize->Base->Resize) and by default adjust the height to keep the current width.
  
• Adjust either the target resolution width or height (depending on what 'Auto adjust' is set to) to you liking/needs.
  

Cu Selur

[shijan]

Analog tapes are very random and also depends of capture devise and movie container. AVI container usually crops 9 pixels from edges and do some additional stretching. MOV container honesty keeps all frame with left and right black edges. Perfectly you need to look for some reference perfect circle object in the movie and based on it decide which PAR is correct for that specific tape.

From this thread https://forum.blackmagicdesign.com/viewt...07#p774671

If you want "analog" flagging (502 active lines) then you set 9 for clap and then 59:54 for PAL and 8 + 10:11 for NTSC (both 4x3). For "digital" flagging which uses all pixels as active area you do 16:15 and 8:9.

59:54 is correct as long as you have clap atom (clean aperture) set to 9. This means you have active area of 720-9 pixels for each side, so 702. Then when you calculate you need 59:54 PAR to get DAR as 4:3.
If you don't have clap set then you use "digital" flagging as 16:15 (720/576*16/15=1.333)

Other solution. You export square pixels (which is modern approach). Then you just make sure you properly taken active lines from your current masters, so you keep proper aspect of 4x3 or 16x9. Quite often old masters have aspect distorted a bit anyway, so this can be a fun game to get it correct

There are also some additional capture options very specific to MOV vs AVI container. In MOV container you need recover back some additional useful data from highlights. In Hybrid this could be done with Levels tool.
You may look for details here https://forum.blackmagicdesign.com/viewt...59#p603596
And here https://forum.blackmagicdesign.com/viewt...59#p604678