If you are using Handbrake you may find that the video you have converted breaks up, perhaps the video is choppy or pixelated.
Here is a solution that has worked for many people who have dropped me a line about it.
One thing that used to work is installing VLC from videolan.org, VLC is a good video player that is free and available for Windows and Mac.
This fix will also help if you have been getting the error message “Your source may be copy protected, badly mastered or in a format which Handbrake does not support”
Here are the step by steps to get things up and running.
Download and install the 64 bit version of Handbrake for Windows from http://handbrake.fr/downloads.php. Make a note of which folder you install it in. By default it is usually C:\Program Files\Handbrake.
You need a file which is libdvdcss.dll and you need the 64-Bit version which is available from VideoLan at http://download.videolan.org/pub/libdvdcss/1.2.11/win64/libdvdcss-2.dll and move or copy it to your Handbrake folder that you noted above. As mentioned it is usually C:\Program Files\Handbrake.
The file you have downloaded is called libdvdcss-2.dll which needs to be renamed to to libdvdcss.dll in your Handbrake folder, this is the folder you just copied the file to.
It does seem that for some people it is not necessary to rename libdvdcss-2.dll to libdvdcss.dll, try it without renaming, if that does not work try step 3 and rename it.
Now try it on a short clip, if you have one, to test it out. I use a short clip so that I can see if has worked without having to wait for a whole film to be converted.