Can play mp4 files on Macs but not Windows

[Harry Trent]

A neighbor asked me to make copies of a thumb drive containing mp4 files that were digitized by Legacy Box from VHS. After completing this task I found the mp4 files would play just fine on a Mac and a Chromebook but not on Windows machine. The files won't open in VLC or 5k Player and Windows Media Player gives an error message saying that that the files are possibly corrupt, a codec needed is missing or the file type is not supported. I have no problem playing other mp4 files on my Windows computer.

I find this odd as isn't mp4 a universal wrapper? I found all kinds of helps online for the opposite problem where mp4 files created on a Windows machine would not play on a Mac but nothing relevant for the other way around.

Any ideas what's going on here and how to work around it?

 

[Cory Cooper]

Hello,

MP4 is just the digital multimedia container that can store audio and video files of different formats. I assume these are converted VHS video files from the Legacybox service, correct?

• What are the file extensions?
• What additional format information is displayed if you perform a Get Info on them in Finder or within QuickTime Player or VLC?

C

 

[Harry Trent]

Hello,

MP4 is just the digital multimedia container that can store audio and video files of different formats. I assume these are converted VHS video files from the Legacybox service, correct?

• What are the file extensions?
• What additional format information is displayed if you perform a Get Info on them in Finder or within QuickTime Player or VLC?

C

Cory, the file extensions are .mp4.

Yes, converted by Legacy Box from VHS.

I need to get back with you with the other information as I returned the flash drive with the files in question to my customer. I contacted him and he'll get it to me soon. The only thing I can figure is that in the conversion process Legacy Box used some setting that renders the files unusable in Windows. When I capture the VHS media to .mp4 on my own equipment they play fine in Windows.

 

[Harry Trent]

Okay, I feel stupid. Sort of. I got the flash drive back from the customer and looked more closely at the list of .mp4 files in Windows File Explorer. I noticed that their are actually two sections of .mp4 files in the list. The first 20 are only 4k in size and have file names like "._1376542-40000.mp4" (without quote marks). The second section of 20 in the list have the same file names except without the "._ " at the beginning of the name and these in the second section are all about 1.5gb in size. These are playable in Windows. I was trying to play the 4k files before and did not notice the size. They are not playable files.

But I also notice that the 4k-sized files don't show at all in my Mac's Finder. Only the 1.5gb ones show. Why is that? What is the purpose of those 4k files?

 

[Harry Trent]

So, with further research I discovered those 4k files are "Trashes" files created by the Mac OS file system on removable media. Legacy Box must be using Mac equipment to do their conversions. I always check the "Show hidden files, folders, and drives" in the Windows File Explorer view options so they showed up when I plugged the flash drive in on my Windows machine. I emailed Legacy Box to alert them that this might cause confusion for some customers trying to view the flash drive files if they also have the "Unhide box" checked. You learn something new every day, as they say.