Reduce the size of a DVDs without noticeable quali

Amok DVD Shrinker is a free program that can shrinks DVDs up to one fifth of the original size without any noticeable in quality.  It is designed to enable the copying of commercial DVDs stored on nonstandard media in order to fit them on a standard 2.5 or 4.7 DVD-R.

Once a encrypted DVD has been decrypted, the data size will be larger. If you try to burn the decrypted data to a DVD you will realize that it exceeds the 4.7 capacity of your burnable DVD disk. In that case, you will need Amok DVD Shrinker, Not only will this program compress the DVD on your hard disk into any size that you want nearly without quality loss, but it will also preserve all the elements of the original including menus and extra features.

Here is more features of  this program:

• User interface: simple interface with just 4 parameters that the user is asked to make. It offers a preview window gives you a glimpse of what the program is processing at that particular moment (the aspect ratio in the preview window is incorrect but don't worry the DVD is processing correctly). you can turn it off for faster processing.  
• Performance: Amok DVD Shrinker is faster than the well known DVD Shrink, with Amok DVD Shrinker, I've successfully compressed a 6G DVD into 4.7G within 25 minutes. 
• Encryption: please note that this program is not designed to remove encryption from commercial DVDs, but rather processes the DVD data once it has been decrypted.