Best file format to use for making a DVD to be played in an older model DVD player?

Hi there. Which video file format (e.g. FLV, MP4, etc...) would be the best to use for making a DVD to be played in an older model DVD player? I have a Toshiba DVD/VCR deck (model No. SD-V392SC2, AC/CA 120V 60 Hz 18 W with the year dates 1992-1997 Dolby Laboratories), and I recently made a DVD using videos found on Youtube, converted to MP4 format using savevideo.me and then burned to a DVD disk using Xilisoft's MP4 To DVD Converter. Unfortunately, while the DVD's main menu appears on my TV screen, I cannot get the videos on the DVD to play. So can the make of DVD player I have just not play MP4's? And if I was to try again with making this DVD, what would be a better format for the video files?