Feat: Custom reference lines for Waveform

[gavalierm]

Can you please add

• padding around the waveform
• reference levels lines for 5% and 95% (or adjustable)

If you have Davinci Resolve the waveform is very user friendly.

[freeman401]

Yes please. I would like to have an option to enable additional reference lines for the limited luma range (specifically at values 16 and 235). If this could be done with adjustable lines, it would be great too.

[norihiro]

Another one also suggested a reference line for the SMPTE color bars.

• https://obsproject.com/forum/threads/color-monitor.143375/post-687549

I'm recently busy to add the features but I think this would be a good improvement.