effect on quality of adding and removing letterboxing

[mgh]

As I understand, it is recommended to remove letterboxing before using filters and add it back later if needed. I am wondering whether there is a loss in quality by adding and removing letterboxing as a process other than the loss in quality due to recoding.

[foxyshadis]

In fact, it'll probably raise quality, because the blacks are then pure black instead of just "mostly" black with just junk from the original. As long as you make sure either the top or bottom box (both if you can swing it) are mod-8 or mod-16, it won't cause a quality issue on that side of the video. If it's not mod-8, you might notice some smearing of that edge.

[mgh]

thanks for the clarification