Handbrake output is poor quality, distorted or scrambled.

This fix resolves and issue where output from Handbrake is very poor quality.  It could also be described as badly distorted or scrambled.  It looks like a kind of codec issue.  This article explains how to fix it.

Essentially obtain this 64-bit version  http://download.videolan.org/pub/libdvdcss/1.2.11/win64/libdvdcss-2.dll

and copy it to

C:\Program Files\Handbrake on a 64 bit system.

http://www.jargonfreehelp.com/fixing-handbrake/