How To Use Mp3 Gain ?, 3 guides - normalization - maximizing Options

[user]

Last update:
2004-08-16


Thanks to westgroveg, we have a brief summary of today's possibilities:

This thread is always coming backup so here a few extra hints for users

• Album analyses  calculates track/album values so performing an album analyses is all you need to do.
  
  
  
  
  
  
• MP3Gain now supports writing changes to ID3 tag so it is 100% lossless, ie. completely reversible.
  
  
  
  
  
  
• As of LAME 3.96 (track) replaygain values are automatically written to the lame tag,
  
  
  
  
  
  
• Unlike MP3Gain, values stored in the lame tag need to be applied during playback which requires more CPU processing & the decoder to be aware.
  
  
  
  
  
  
• Foobar can automatically scan & adjust replaygain values without any need for MP3Gain but of course some of us don’t like this audio player.
  
  
  
  
  
• One more thing, make sure, you tag before using replaygain or instead of your replaygain values being hidden they appear in the comment field for some reason which can be annoying.

This post has been edited by user: Aug 20 2004, 11:33

[AreteOne]

3) no, no, no (this is my opinion, if mp3 is your goal, as you have written).

But if I don't, then my MP3s will almost certainly clip. I see you're ripping and encoding in one step. Leaving aside the issue of .wav editing before encoding, how do you prevent clipping in your MP3s? I'm doing this to reduce the amplitude of the source and prevent clipping, not to increase its amplitude before encoding.

4) umm, --alt-preset standard with addition -V1 is nowhere recommended. There are no test sessions made with this. In fact, the alt-preset was optimized as it is, so you do only cause trouble by adding NOT RECOMMENDED SWITCHES. For higher or lower quality or filesize, choose recommended presets from list !!

I asked for feedback in the presets thread, and so far haven't received any. If there hasn't been any testing, how do you know that adding this switch will cause trouble? I understand that it's not on on the recommended list, but that doesn't mean it therefore causes problems. As I wrote in the other thread, I remember agreeing with the argument for V1 on the r3mix site, and would like to keep this in the absense of knowledge that it's adversly affecting the encoding. I did read a message where someone reported swooshing with -V0. I guess I' m just one of those people who, when told "You're not supposed to do that!", reply, "Why not?" But this is for another thread.

5) check for clipping (yes, here, not earlier like in 2, normalizing the mp3 is lossless by mp3gain, so it is better, and otherwise you would have double work, here in mp3gain you can adjust volumes much better than in step 2.)

Well, if your MP3 is clipping at this point, it's already damaged, right? I mean, if amplitude is an 8-bit signed integer and there are frames where the value is 16384, using MP3Gain to reduce this value won't get back the information that was clipped off during the encoding process, right? Yes, after you apply the gain change, a second analysis will report no clipping, but that's because you reduced a clipped number. My goal is to be sure there's never a clipped number in the original MP3; after that, you can move it up and down all you want (as long you as don't clip it in the process), and the changes will be lossless, right?

When you run MP3Gain on your just-created MP3s and see that some are clipped before you apply any changes, how do you feel about that?

I don't need 8 steps...

Well, I'm all for efficency, too, but all my work is going thru a .wav editor for the reasons I've already explained before it gets encoded, so using EAC to encode and tag isn't an option. I'll gladly modify what I'm doing as long as it doesn't harm the result. That's why I want to better understand how gain modification affects .wav files as well as why adding the -V1 switch may affect the quality of the MP3.