I have some files which although claim to be 320bit are reported by 'FakinTheFunk' ans 'Spek' as a lower bit quality.
Some may have been 'overripped' by those who falsely think this creates a better quality, but I know from my own experience that ripping a CD to 320bit also suffers this way as sometimes the source material is of a suspect quality.
Keeping these files with other actual 320 bit files causes issues when creating a playlist as clearly the difference can be heard.
So, is there a way to change the file content to reflect the bitrate quality, say 128 for a 320 bit file?
I don't want to rerip as this makes things worse!
Regards and thanks
No. This type of data cannot be modified by MP3tag.
You would need a program that either re-encodes the files or examines the files and sets the "corrected" bitrate.
The files are still 320 kbit/s even though the source originally was something else. I would maybe add a comment or use a custom field to tag the files of poor quality source, but it depends on your software if it can use it.
Some think that converting low resolution rips to a higher bit rate after the fact will somehow make them sound better. Unfortunately the reality is that once the detail destroyed in the initial rip, it cannot be restored. Only ripping from the original source again can restore the resolution. And this assumes the original source is of some significant quality in the first place. But it happens in the wild all the time.
There is no tool I am aware of that can detect this. The bit depth (typically 16/24/32) and sample rates (44.1k/48k/88.2k/96k, variable, etc) are a couple of technical file details that mp3tag can display but not change.