>> Interesting concept. You seem to be describing a realtime compressor/limiter.
One thing to remember is that there's more to implementing a compressor/limiter than just determining the volume of a given sample. There are other things to be concerned with such as attack/release and hold times. If these are not carefully adjusted, you get strange artifacts like zippering effects or snare drums that sound gated.

Yeah, that's one reason why I made the suggestion that the apparent volume could be precalculated. Mind you, careful selection of the "chunk" size should minimise most of those kind of problems. I haven't done any experiments yet, so I couldn't really say.

I'm not sure whether I would prefer to hear artifacts or nothing at all.

>> Personally, I'd be happy if I could just tag each track by hand with a relative volume modifier.

That ought to be very easy to implement (just have an attribute that you can set from emptool (or emplode if you use windows)) but it's still not going to help for the quiet sections in Mars or 2112 (two tunes that I always have problems with).

Richard.