Matt Morgan <minxmertzmomo@xxxxxxxxx> wrote:
> I have a problem with a lot of my CD's. I'm sure this is familiar to a > lot of people-the sound levels don't match. There's always that one CD > that's a lot louder than the others, so you can't put it on mixes, > etc. >
I'm not sure, but I think many CDs use the full digital sample range (which is a good thing if you think about it).
> It looks like grip's "calculate gain adjustment" (encoding config, > options tab) will be a step to fixing this problem for new tracks. > Right? >
Exactly, though it doesn't do the peak volume tag needed for clipping protection.
> And then, what about existing .ogg and .mp3 files? Can I fix them, or > should I just re-rip and re-encode?
Google for replaygain and vorbisgain. They add tags specifying a preamp adjustment based on the perceived loudness of a track/ album (using acoustic modelling, similar to that used for audio compression). These values can be calculated at any time, and do not destroy information on the track (it's a lossless process). So you can apply it to your existing tracks. The current version of XMMS can understand the tags (I think it's down to the input plugin), not sure about the Jukbox or whatever it's called.
To use grip to rip to vorbis, you're going to need to modify the command line it uses. I don't have an example here, but the places to look for info are: man oggenc (for the options to set custom tags when encoding), the grip help docs (for the variable containing the calculated adjustment), and probably the vorbisgain docs for the correct tag names (or just vorbisgain some existing tracks and use vorbiscomment -l). I prefer using vorbisgain however, because grip does not produce all four tags (album gain, track gain, track peak, and album peak).
-- imalone
