We often use DVD to store video and data file. Varieties of DVDs are sorted by the way data stored.
DVD-9 holds 8.5GB and is supported by the DVD+R and DVD-R formats. It is also known as Single-Sided Double Layer (sometimes called Dual Layer). The official names are DVD-R DL and DVD+R DL.
DVD-5 holds 4.7GB and is supported by the DVD+R/RW and DVD-R/RW formats. It is also known as Single-Sided Single Layer.
If you want to compress Double Layer DVD-9 to Single Layer DVD-5 on Mac, you must use one Mac DVD Copy software. Download this Mac DVD Copy to have a try;
Step 1: Insert your DVD and select the copy DVD mode
This software provides users with three copy modes - "Full Copy", "Main Movie" and "Customize".
Step 2: Select souce
Choose DVD-video disc from the source pop up menu.
Step 3: Select target
From the "Target" pop up menu, select the DVD disc, and on the type of DVD disc, please select the disc type "D5(4.7GB)"(there are three types of DVD discs: D5(4.7GB) Disc, D9(8.5GB) Disc and customized disc.)
Step 4: Start to compress DVD
Click "Start Copy" button to begin your DVD compressing.
Ready to try or buy this DVD Copy for Mac