Blender VSE: Absolute VS Relative Masks
This is meant to append the masking tutorials found in the Blender VSE Series (II and III specifically), found in the full playlist below:
• Blender VSE Tutorials
2:36 Relative Masks (In Brief)
5:33 Absolute Masks (In Brief)
7:37 Detailed Walk-through
Note if you apply relative masks to specialty strips like colour strips, as you expand the strip things are automatically offset. You can think of colour strips as being infinitely long, but the lengths are only calculated based on the amount shown in the timeline.
In terms of masking method:
The benefits of breaking things up into static masks means extra work upfront, but means you are less likely to make an error (very time costly), as well it lets you easily edit any particular section previously made. You'll have to decide the merits of each masking method you choose based on your medium (the footage type you edit and its purpose). For anime footage for example, every movement is duplicated across 2 frames. This means when doing the automatic keyframe method of masking: I have to reapply the previous keyframe to the next frame and make sure I always move one way (left to right or viceversa). Now what would you do if you needed to update/correct a part of this mask's keyframes...? Well you'd need to apply an update to each keyframe individually, and ideally copy your work to the 2nd to save time. This is hard to do in the UV image editor. A good method is to correct one of the two keyframes in the UV, go to the dopesheet, delete the keyframe of the second duplicate frame in the dopesheet and duplicate and place the corrected keyframe to the 2nd one's location.
If there's something specific you want to see in a tutorial, you can let me know....somehow. For example you may try howling at the moon. Such methods are as good as any other these days.
Yes the thumbnail is corny as can be.