Why does Photos recognize EXIF data in a .MOV but not an .MP4?

Question

I have a script that I wrote that uses HandBrakeCLI to convert files from .MOV to .MP4, but then also attempts to preserve various EXIF metadata by using exiftool by using the -TagsFromFile operation to copy tags from the older MOV to the newer MP4 (and then a subsequent additional run for -FileModifyDate<CreateDate).

While everything seems to work and the EXIF tags appear in the output MP4, when I import the MP4 into Photos I don't see any information about location, or the iPhone model that I captured the video with.

If I use exiftool to view the metadata of the original MOV and resulting MP4 I do see that the MOV only has 5 GPS-related items (Coordinates, Altitude, Alt. Ref, Latitude, Longitude, Position) while the MP4 has the same but multiple copies of all except 'Position'. Additionally, I can see that the MOV has 'Model' for iPhone, but the MP4 has 'Model' and 'Camera Model Name' both referencing the iPhone.

Despite this plethora of data, Photos.app says it doesn't know what camera took the video nor does it know what GPS location the video was taken.

Does anyone have any insight on this? Is it because it is an MP4 and not a MOV? I'm assuming that Photos.app is getting camera/GPS from the EXIF data in the first place, so why doesn't it recognize it from the MP4?

Answer 1

Doing some research and asking on other forums, I found that Photos.app does not discriminate against MP4 versus MOV, but rather that Apple products are very picky about reading the data and don't always follow the Quicktime standards (which they created). To add to the problem, there are tags with the same name in different Quicktime group 2 families (ItemList, Keys, and UserData).

In my question, I noted that I was using exiftool -TagsFromFile source.mov target.mp4. Apparently the tool will copy most/all of the tags, but will put them in places that it prefers. The way to work around this is to add -All:All between the source and target filenames as this forces the tool to copy all tags and put them in the same place in the target (not its preferred location).

So to complete what I was doing, you would use a command like:

exiftool -TagsFromFile source.mov -All:All target.mp4

(Primary information sources here, here, and here.)