Tags written to M4v and VOB files not showing in exiftool or Lightroom

[Damit]

I tagged some video files for the first time with some keywords and when I went into lightroom I did not see them.   I used the exiftool , as well as FastPhotoTagger and they did not list them either.  I looked in the preferences and I see these formats are supported.  Why can I not see the keyword tags anywhere other than in the Keyword Panel in iMatch?

[Mario]

As far as I know, VOB was used by DVD's back in day? 

ExifTool does not list VOB as a writable format and there is no standard for metadata in VOB.
See https://exiftool.org/#supported

IMatch stores XMP metadata for file formats which don't support embedding XMP safely in an XMP sidecar file.
That's the most standardized and compatible format you will get.

If your other applications support XMP metadata for your VOB files, I don't know. Did you contact their support?
Maybe they don't handle XMP data or are not prepared to handle XMP data for the VOB files?

[Damit]

OK, so they are in a sidecar.  Got it. I guess I will try to figure out why Lightroom is not looking for one or reading it. I was confused as far as the VOB, as it is listed in the preferences under Video files, but I can see, checking the link, that exiftool basically does not support it.  Thanks for the clarification!

[Mario]

IMatch supports VOB and many other file formats (> 100!) and many of them don't support any form of embedded metadata. Or metadata at all. Or they are write-once formats.

In addition to storing metadata in the database, IMatch can persist all XMP data for these file formats in XMP sidecar files.
This allows other XMP-supporting applications to read the metadata IMatch has written. If they care to.
Metadata in video files is an even bigger mess than metadata in image files.

.MP4 is probably the best modern container format to use for videos. Usually you can losslessly convert existing videos into the .MP4 container format using free tools like FFMPEG or Handbrake. IMatch supports embedded XMP data for MP4 files.

[Damit]

Excellent advice! I will convert them! I will use my remuxer to do so. Thank you!