Embed hierarchical keywords in mpg video?

[henryS]

Is there a way to have Hierarchical keywords inside mpg video files rather than being written to an xmp side file? Wish to avoid having additional files created.
Many thanks!

[Mario]

There is no standard for embedding XMP into video files.
Some video formats (most video "files" are just containers which contain multiple streams of audio and video and whatnot) theoretically allow embedding of XMP data, but it is not standard and hence IMatch uses the safe way of keeping the data in the XMP sidecar file.

I have recently seen that some MP4 containers which had embedded XMP metadata.
But the software/camera who did this did not record its name in the XMP record so I don't know more.

You can configure IMatch to embed XMP metadata into video files via Edit > Preferences > Metadata 2: File Formats.
ExifTool supports writing a small range of containers. I'm quite sure about MP4 and MPG.
If you do this, make sure you keep an eye on the ExifTool output panel for warnings and error messages and that you test the video files very carefully with all video editing and display applications.
As I said, there is no standard for metadata in video files (except for the old Apple QuickTime data, which is still mostly an Apple thing).