[vorbis] (Un)Usefulness of Vorbisgain?

[David Tenser]

There's two things I didn't understand about the Replay Gain by reading 
the FAQ. It does several calculations to get the best Replay Gain to 
add/substract to the song. Let's say the result was -5.2dB, will that 
energy be taken out of the actual samples, or will it just tell the 
player to play this file 5.2dB quieter?

Also, will this value of -5.2dB be applied to the whole song, even the 
quiet parts, thus not leveling out the volume for that particular song? 
Or to put it in other words, does it apply dynamic compression to the 
song, or does it just amplify it according to the results of the RMS 
tests etc.?

Luke Usherwood wrote:

>Thanks for the Reply Gain link.  That explains a lot.  Brilliant idea, BTW!
>
>Here's a tip for anyone who's reading the Replay Gain FAQ for the first time.
>
>Note the use of the word "Compression" in the FAQ might confuse people who aren't familiar with the musicical sense of the word.  In the FAQ, Compression does not mean "technique used to shrink the size of a data file" (like OGG).  In the musical world, compression is "adjusting (reducing) the dynamic range of the sound, usually by making softer bits of the music louder".  For example a compressor is commonly used on an electric guitar to even-out the volume of the notes being played.
>
>In my opinion, compression is good when used on a single instrument, but not on a finished recording.  For example, imagine a piece where a quiet sound like a flute playing along, and then a loud drum starts playing.  After compression the volume of the flute will be made louder, and then will fade away suddenly when the drum starts... even though in the original piece the flute is always the same volume.
>
>On the other hand, compression can be useful in enabling you to hear quiet parts of music in noisy environments.... such as in my old putta-boom car.  One of the things I want to do with my car stereo some day (a home-built MP3 player running on a PC in my boot) is to get the PC to estimate the background noise, and dynamically add compression when necessary.  I.e. when the master volume is quiet compared to the background noise, use compression, but when you crank the volume up, take away the compression to make the music sound better. 
>
>In the mean time, i just always listen to my music loud.   Which isn't so bad :-)
>
>
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