Windows 10 photos app. What file extensions does it support (and not support) ?

My laptop:

Windows 10 Home

Version 1607 (OS Build 14393.576)

Microsoft Photos 16.1118.10000.0

All available MS updates applied.

I'm trying to learn what files extensions the Photos app supports.

I wonder if there is a document somewhere (that, I no doubt, missed) which states the extension that Photos will handle.

Or if someone just knows, and would be willing to share,  that would be great as well.

The Photos app seems able to handle files with the following extensions on my laptop. (On my laptop.)

In that, it will display or play, the following ....

.MOV

.MP4

.WMV

.JPG

.JPEG

.PNG 

But, it doesn't seem to like files with an extension of .MPG.

At least I am unable to figure out how to get the Photos app to play them.

So, I thought I would make an attempt to learn everything that the PHOTOS app should be able to handle.

Thanks in advance for any and all replies.

Ray in Wisconsin