I just did some testing and found that metamp3 seems to be extremely »intelligent« on updating replay gain values:I used a command likemetamp3.exe --2 --replay-gain "file1.mp3" "file2.mp3" "file3.mp3" …on the tracks of an album that had replaygain tags before, except that I deleted them from one file, to see what it would do.Apparently it »detected« that one file from the album had no replaygain tags and so it would have to recalculate all files in order to find an appropriate album gain. (Which it did.)When using exact the same command again, it would just say »Updating ID3…« and be finished much faster (without re-calculating all the gains again).Can this really be true? Did anyone verify this?If that is really how it works – KUDOS again to Tycho!!!
I guess I could start with making a new id3lib based beta with some of the suggestions that has been made here as they are quite minor. I will in any case have to start out with the current metamp3 code base.
1. Next version will support the prevent clipping option, along with other mp3gain options (equals).2. It does both when specifying multiple input files, e.g. *.mp3, just like mp3gain. Only track gain when specifying one input file.edit: also, the executable will be linked statically with the VC8 runtime libraries.