I have a Blu-ray dvd player. It works perfect on any purchased or rented dvd. I have home videos that I wish to record on a dvd and play on my player. I have recorded in avi, dvix, wmv and the player says the disk is not compatible. All play on the computer I use to record them. It was suggested to me that -R media is needed for home stand alone players. I have been using +R. Main question: What format is the standard purchased retail DVD recorded in? If there are two or three please advise me of that also. And, does the -R or+R matter?