Blurring a video is actually quite simple with FFmpeg, although you will need a few attempts to see what settings work best for you.
Sometimes you may want to blur a video, for various reasons. You may want to anonymize the people in it, you may want to use it as a background etc.
You can blur an image using different calculations / formulas and the results will be slightly different. The most common types of blur are radial blur, box blur, variable blur and gaussian blur.
A gaussian blur is a particular type of blur. It is a type of blur effect that uses a Gaussian function for calculating the transformation to apply to each pixel in the image.
You can increase the intensity of the blur with a second parameter, below uses a radius value of 50 that is then applied 5 times resulting in a very strong blur effect.
In FFmpeg the gblur filter takes 2 parameters, the standard deviation and the number of steps for gaussian approximation. Standard deviation will range from 0.5 upwards while steps can be a number from 1 to 6.