Where does the metadata reside on the MP4 files?

[dashcammer]

I've thousands of mp4 files (dash cam) stored on cloud.
To download them all to get all metadata will be crazy.
I can, however, download the first x bytes of every file and process it for metadata.
Any idea if that will work?

Thank you again ..

[StarGeek]

There's no guarantee that the data will be near the beginning

You can always try to throw a partial file at exiftool to see what happens.

In my experience, about half of the time metadata is at the end of an MP4/MOV video, so in these cases you would need to read the whole thing.  If it is at the start, then you could just read the first 1 MB or so, but you would have to do this because ExifTool will always read the whole thing to look for metadata at the end.

- Phil

The -fast option will help for files with the data near the beginning according to more recent posts from Phil, but if the data is at the end, there's no other option than downloading the file.  And if you're looking to extract a GPS track from the file, you'll have to download the whole thing because the data is embedded in the stream.

[dashcammer]

I see.. thank you StarGeek for the help..