Maybe this is the reason why Florian made $rg2sc() a »one-way route« (by not implementing $sc2rg()). Keep in mind that iTunes SoundCheck normalizes based on the loudest audio sample in each track, so its not a real ReplayGain value! iGain and iVolume (3rd-party apps) make a better value since both are using the ReplayGain algorithms instead. Would be nice to see this in $rg2sc() and $sc2rg(), eventually … (So I wouldn’t have to do this stuff in Perl all the time …) I guess Mp3tag could easily fill in value pairs 0/1, 2/3 and 6/7 with the correct values. (This is also why Mp3tag’s »brute-force all values same« succeeds: n/1000 is always more than n/2500.) ITunes is choosing the maximum value of the both first pairs (of the first 4 values) to adjust the whole song. (Suggestion: Make it an optional second parameter in $rg2sc().) Maybe we should find out how to set a value that prefers our songs instead. Apple secretly kowtowing to corporate interests and their desire to control our listening habits. This is to insure that certain songs get played more often than others. ** = Probably another place to hide the »listenability index«, a complex algorithm that factors in a wide range of values to determine if your songs have »maximum listenability«. Otherwise: X = 1000 * 10 ^ (-0.1 * Y) where Y is the adjustment value in dB and X is the value that goes into the SoundCheck field. = The value 0 is special, the equation is not used and it is treated as "no Soundcheck". 6/7: The peak value (maximum sample) as absolute (positive) value therefore up to 32768 (for songs using 16-Bit samples).4/5: Not sure, but always the same values for songs that only differ in volume - so maybe the »listenability index«.0/1: Volume adjustment in milliWatt/ dBm.The first value of each pair is for the left audio channel, the second value of each pair is for the right channel. The relevant information is what is encoded in these 5 value pairs. The tag can be found in MP3, AIFF, AAC and Apple Lossless files. These 10 values are encoded as ASCII Hex values of 8 characters each inside the tag (plus a space as prefix). The iTunNORM tag consists of 5 value pairs. but the regular soundcheck track values are virtually identical to what you are getting with replaygain track values. I do this so I can make the soundcheck values "album gain". it will then create new itunnorm values automatically. Or simply delete files from itunes, then readd files. If you think your itunnorm values are messed up, the best thing to do is simply delete the ITUNNORM field in mass, then rerun your mp3tag action on all the files to create new itunnorm tags from the replaygain values. There should be some repeats (see one of my examples below). Maybe you're saying that the itunnorm value is repeated many, many times for a single track. The itunnorm values are always a very long string of numbers/letters. each track has a different replaygain value and a different itunnorm value. Perhaps I'm misunderstanding your question.
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