A mapping is important. And for the DDJ-400 the mapping is included in the software, and the controller is listed as Natively Supported. I have a DDJ-400. It works great with VDJ. I rarely use it with Rekordbox. Posted Wed 09 Jan 19 @ 4:00 pm. Groovindj PRO Infinity Member since 2007. The DDJ-400's buttons and knobs are arranged in the same way as those on our professional NXS2 set-up. Develop your skills using an interface similar to that of our club-standard player, and enhance your mixes with Sound Color FX and Beat FX featuring curves taken from our DJM-900NXS2 mixer. You'll soon feel comfortable performing in DJ booths.

Pioneer Dj400 Windows Update
MIDI Operation

Find more details at
http://www.virtualdj.com/wiki/VDJ8script.html
AUDIO Setup
Pioneer Ddj 400 Software Spotify
The unit has a pre-defined Audio setup and a special button in the AUDIO tab of Config to provide that.Please read the manual of DDJ-400 for further functionality https://www.pioneerdj.com/en/support/documents/ddj-400/
For further software settings please refer to the User Guides of VirtualDJ 8.
http://www.virtualdj.com/manuals/virtualdj8/index.html
Software Pioneer Ddj 4000
Controls