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Lossy Audio Compression => MP3 => MP3 - General => Topic started by: sTisTi on 2006-01-03 10:08:54

Title: Replaygain & MP3Gain
Post by: sTisTi on 2006-01-03 10:08:54
Hi,
I'm in the process of cleaning up my whole MP3 collection (~830 albums) mainly because of sloppy tagging and thought I could add replaygain info as well while I'm at it.
The problem now is that I have already applied MP3Gain to some albums which I've noticed to suffer from clipping. I applied the "Max no-clip gain" per album for these. What happens if I run replaygain (I'll probably use foobar for this) on these albums? Will it analyze the current loudness of the MP3s and calculate the remaining adjustment to reach 89db? Or will it screw things up and take the original loudness value (which is stored in the tag by MP3Gain IIRC?) and thereby make them actually quieter than 89db?
In other words, do I have to undo all gain changes made with MP3Gain before doing replaygain analysis, or is this not necessary?
Another thing are the replaygain values calculated during Lame encoding which are stored in the LAME tag. Are these in any way used when doing a replaygain analysis? This would also be problematic for the tracks already changed with MP3Gain, because the replaygain-adjustment in the LAME tags is obviously wrong for these files now.
I hope someone can clear up this confusion. Thanks!

P.S.: Another foobar-related question. IIRC, I can comfortably run the replaygain analysis for all albums at once when adding them to the album list, selecting them all and then choose an album-based replaygain analysis, right? Forgive my ignorance as a foobar newbie, but how do you select multiple albums in the albumlist window?? I can only ever select one album at a time, the usual stuff (holding down CTRL or SHIFT when clicking on albums) doesn't seem to work.
Title: Replaygain & MP3Gain
Post by: halb27 on 2006-01-03 11:38:52
Why not use MP3Gain for further replaygaining to 89 db?

MP3Gain's advantage is that it effects real audio stream's loudness and is not only stored as an additional information. So every software or player takes advantage of replaygaining.
Title: Replaygain & MP3Gain
Post by: PoisonDan on 2006-01-03 11:45:41
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What happens if I run replaygain (I'll probably use foobar for this) on these albums? Will it analyze the current loudness of the MP3s and calculate the remaining adjustment to reach 89db?[a href="index.php?act=findpost&pid=354188"][{POST_SNAPBACK}][/a]
Yes.

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Or will it screw things up and take the original loudness value (which is stored in the tag by MP3Gain IIRC?) and thereby make them actually quieter than 89db?
No, the tag MP3Gain creates will be ignored.

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In other words, do I have to undo all gain changes made with MP3Gain before doing replaygain analysis, or is this not necessary?
Not necessary.

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Another thing are the replaygain values calculated during Lame encoding which are stored in the LAME tag. Are these in any way used when doing a replaygain analysis?
AFAIK those values are also ignored, so it will not affect the replaygain analysis at all.