Why foobar2000 shows track peak (=true peak) tag -1.90dB but mp3tag shows 0.803314? What means 0.803314? 1.0 represents digital full scale? There are diference methods to show peak? And what does this peak show - digital peak or true peak? sometimes this value is positive in foobar2000, so it means, that track peak tag repents true peak?
Can you post a screenshot of extended tags window for a file you have in question? There should be no difference for these tags on the same file.
But do note that the peak values are not the same as the Replaygain values. There are track and album levels of both peak and gain values.
It would be helpful if you could show us a screenshot of the extended tags dialogue of a single file with the problems that you encountered.
This would also reveal which tag versions are stored in the file.
If the header of the extended tags dialogue shows something like "APE", then also a screenshot of the Options>Tags>Mpeg settings would be nice.
There are programs that write replaygain data to APE tags exclusively, others use ID3V2.3 tags.
So, it would be necessary to check whether gain data could have been written to different tag version fields and which of these fields are being read.
True Peak in foobar2000) & TrackPeak in mp3tag, I set difference names. Since the value of this parameter may be positive (+ 1.5dB in foobar20000 and, say, 1.50000 in mp3tag), so I think it shows the true peak, not a song's write level, because write level is not greater than 1 (mp3tag) = 0dB (foobar2000). Apparently 1 and 0dB are different ways of displaying
Then the question is: why the tag is called replaygain_track_peak and not replaygain_true_peak, and the answer is another question, is there a tag that shows exactly the recording level from 0 to -96dB and quieter?
You would have to ask that the programmers of the replay gain investigating software. MP3tag shows the user-defined tag field "as is".
And as MP3tag does not deal with the audio part of a file, it has not a lot to do with the naming of theses tag fields.
It appears there are different tags being used, as your Foobar image is actually referencing one called
replaygain_track_peak_db that isn’t listed in your mp3tag column definitions.
With that same file, when selected in mp3tag, open the extended tags window with Alt+T, and post a screenshot of that. This will show a list of all tags that have been written to that file, I suspect there are more than just these two.
I found, that in foobar2000 tag calls %replaygain_track_peak_db%, I create column there without "_db" and now foobar shows the same value: 1.091985. I still think it's the same meaning expressed in different ways. What caused me confusion was the lack of this "tag" expressed in dB in mp3tag. It turns out that %replaygain_track_peak_db% is not a tag at all, but just a column in foobar2000, which makes the display of the true peak value understandable. The file has not this tag (whith dB):
Values such as 1.091985 say nothing to a person, only that the peak is higher than 0dB, and how much higher can be found out only if this number is translated into dB. It is bad that replaygain in foobar2000 does not create this tag with dB
Question: Is it possible with the formula to translate this value into dB so that the column shows dB?