Yes, you need root access for files other than pictures !
The particular method that doesn't require root access is only supported from Android 5.0.1+ ( i think )
You need to download Disk Digger ( photo recovery ) - rootless Disk Digger ( All file types, needs root ) I personally use Disk Digger Pro from Defiant Tech'
[Google Store Link for Developer Defiant Technologies][1]Google Store Link for Developer Defiant Technologies
Anyway i hope this helped.
Also,
• The Photo recovery doesn't need root access because it uses a new inbuilt photo recovery feature in Android 5.0.1+ devices
• The root access method will do an entire sector by sector scan on the internal storage, for the selected file types ... Several are supported. [1]: https://play.google.com/store/apps/developer?id=Defiant%20Technologies%2C%20LLC&hl=en