Corrupt file headers/tags in MP3 files

I've an odd problem that has occurred on (fortunately only) a few MP3 files. Some have been corrupted such that the music plays fine but the following items have disappeared from the file headers/tags:

Codec
Bitrate
Frequency
Length

Also the genre has been changed to "Other" - this was how I spotted the problem. Anything altered in the usual tags, I can change back with Mp3Tag. But the four fields above I can't figure out how to alter.

The corruption occurred some time before the oldest backup that I have so I can't recover the files from there.

This isn't critical and I could re-rip the CDs but I'm curious to know if I can change these fields somehow.

see the HowTos:

Thanks ohrenkino but this isn't a bug report - the files weren't corrupted by Mp3Tag - I just wondered if Mp3Tag could somehow be used to fix the problem and if not is there another tool I can use to fix what's wrong?

The programs linked in that HowTo are the tools of choice if you want to investigate what is wrong with your files and whether something could be repaired.
Mp3tag does not deal with the header and the audio part, it handles the tags.
So my answer was meant to be a serious piece of advice.
(I did not think you issued a bug report - and if you did then I probably would have asked you to investigate the problem further with those tools).

Sorry, I misunderstood. I'll have a look at these tools and report back.

I've looked at both tools but unfortunately neither does what I want. Nonetheless, having downloaded/installed them, I'll keep them - they may be useful in the future. I think it's probably going to be easier to re-rip the CDs. Thanks anyway ohrenkino.

VBRfix might help:
https://hydrogenaud.io/index.php/topic,67076.0.html

Thanks ryerman, I'll take a look.