I need to hide faces from videos I make. I've found tutorials on blurring, which are great, but the render times are too long to be practical.
So in place of that, is there a way to pixelate the face in using the Video Sequence Editor?
I added a pixelate function to the Blender Addon VSE_Transform_Tools using 3pointedit's method. You could download the addon and use the P key to apply pixelation, then set the severity of the pixelation with the tool that pops up.
For a stationary subject, I recommend using the crop tool that also comes with the addon to crop out a face.
For moving subjects, I recommend tracking, then applying a mask.
The image above was quite legible in the original and has been quantized or pixelated in Blender.
In the Blender screen capture above. Note the settings.
Explore Probes and Filter to suit your taste.
In 3D view the material texture can sample images at reduced resolution to produce pixelation. You can create a moving object such as a sphere which might be positioned to cover a face and produce a "mask".
So two texture planes and one mask object are indicated, perhaps in different render layers.
In the Compositor phase of rendering, the mask image can then be used to compose the original video with pixelated video selectively with an alpha over node.
This explanation is a reduction. I cannot comment on speed characteristics of your machine.