I have a Sony home DVD recorder and it formats the discs the first time I insert them (this is probably a kind of initiation or fast formatting, not a complete process).
It also has menu options to format discs, but that's as chef told you it only works for RWs, as you can format a DVD+R only once. So, as a principle when you call this menu the discs will be already formatted and the device will do nothing.
However, if you read the user manual you will see that your recorder will probably be quite demanding about the discs you "give" to it.
If your discs are fast DVDs (kind of 16x speed) you may find problems, as this type of video recorders is happy with 2x - 8x discs and the firmware may not recognize the faster (newer) ones.