How can I burn an mp4 file to a DVD that will play on a DVD player

Be sure you select the correct project type in the Video tab in Toast. You want DVD-Video.

Then add your video by dragging to the window or using the + button in the bottom right of the video window. My example is an MP4 file. It won't convert to DVD until you feed a blank disc into your super-drive.

Understand the video quality is dependent on the source. If it's a youtube video you download it will be pretty sad ... worse than VHS. If you have HD quality from a camera original it should look excellent, but only as SD quality. You need the BluRay plugin and burner for HD discs.

The option to burn a 30 minute HD on a standard DVD doesn't look good and many BluRay players won't like the disc anyway.

You need a DVD authoring app like Apple's old iDVD or Roxio Toast.

My version (Toast 14) is old, its the last that would work with my 2007 iMac and El Capitan. You'll need to check Roxio's site for compatibility for your set up. iDVD will import from iMovie. My experience iDVD is very slow compared to Toast however it does offer better menu and disc navigation tools. Toast menus are simple.

If the video file created in iMove is 720 or better then you should have pretty good results with Toast. There are quality settings in both applications. Its best to create a short test video, and if you use erasable DVD-RW you can test quality in your set top player. But you'll never get better than 480 quality on a DVD.

Many newer DVD and Blu-ray players don't need a movie disk to play back .mp4 files or JPEG images as a slide show. Just burn it as a data disk.

Check the manual for your player first, though. See what it says about playing back data disks.

That's the main thing the software does. Convert digital data to a different media (DVD).

Typical cruddy DVD quality at 480 size.

This is from the Toast 7 Titanium guide.

From what little I've learned from scratch - in a few minutes from searching - there is a need to have a conversion so mp4 can be used in standard DVD format; and then if put to physical media, that also has to be compatible with a regular non-propriety DVD player. ~ And some conversions take files from mp4 to mp3; that may not be a direction to go.

Some names I've heard of before are mentioned in topics found in search results; such as 'Handbrake' and others. Not sure if the old software 'Burn' could be useful in this; been years since I'd had a DVD or CD Combo or Superdrive that worked.

A few ideas arose from the first search here; variables may reveal more (or less?) content:

https://duckduckgo.com/?q=burn+mp4+file+to+DVD+for+standard+DVD+player+El+Capitan+mac&t=ffab&ia=web

To expand a bit on QuickTimeKirk's answer, iDVD was bundled on older Mac hardware and is part of iLife 11. The app is discontinued. If you have your original system discs that came with your Mac you may be able to reinstall iDVD. If you're still running el Capitan on an older Mac it will run. https://www.megawatts.com/home/380-apple-ilife-11-single-user-dvd-license-only-n.html

Roxio Toast runs on newer hardware and recent MacOS.

I've used both, be patient re-encoding is a slow process. Toast is much faster than iDVD. Key to encoding and burning success is to turn off sleep in your System Preferences. Sleep will corrupt the DVD burn step.

If your MacBook is Intel duo or better processor it is 64 bit. El Capitan is 64 bit. I have not tested Toast versions higher than 14. Scroll up this thread for the link I posted for a surplus mac retailer who has iLife 11 for about $18. It contains the last version of iDVD.

There is a free app called Burn. The developer just released an updated version. You may wish to give it a try.

https://burn-osx.sourceforge.io/Pages/English/home.html

" I do not have this version of Toast. "

What version of Toast do you have? Many versions can burn DVD's

If you give details ,then more help might be possible.