Not understanding the ReplayGain scanning options, Recycled: learn to read kthx Options

[kwanbis]

I took an mp3, and replaygain scanned it, with target as 89db. It gave me -9.53dB.

Then i removed the replaygain data, and re-scanned, with target as 95dB, and it gave me the same target of -9.53dB.

Is that correct?

[Yirkha]

If you are referring to the option "Preferences > Advanced > Tools/ReplayGain Scanner/Target MP3 alteration volume level (dB)", yes. That option is used only for the "MP3Gain" functionality (Context menu > ReplayGain/Apply xxx ReplayGain to MP3 Data).

[kwanbis]

If you are referring to the option "Preferences > Advanced > Tools/ReplayGain Scanner/Target MP3 alteration volume level (dB)", yes. That option is used only for the "MP3Gain" functionality (Context menu > ReplayGain/Apply xxx ReplayGain to MP3 Data).

What i'm saying is that no matter what target i use, i get the same dB +/- value.

[Yirkha]

Because as I said, that option doesn't affect the scanner.

[lvqcl]

What i'm saying is that no matter what target i use, i get the same dB +/- value.

This setting doesn't affect replaygain calculation. It works only for changing loudness of MP3 file (via "apply gain...").

[kwanbis]

You mean it only affects when i "merge" the replaygain data to the mp3? If so, it is very confusing.

[Yirkha]

In what way specifically?

[kwanbis]

I assume the calculus of the replaygain +/- is based of my target, so if my target is 96, the calculus is +/- what is required to achieve that value, and which should be different of the +/- value needed to achieve a target value of 89.

[lvqcl]

So RG should work differently for MP3 and all other formats (OGG, FLAC, etc.)?

[kwanbis]

No, it should be this way for all supported formats. Meaning if i change the target value, it should be used for all calculations inside f2k.

This post has been edited by kwanbis: Nov 29 2009, 04:10

[jeremija]

If I understand correctly,

ReplayGain in foobar2000 always scans the files and calculates the gain relative to the standard 89dB value. Changing the slider will only affect the reproduction loudness. For example:

Scanned replaygain value: -5 dB (relative to the 89 dB reference level)
RG preamp set to: 89 dB (the player will turn down the volume for 5 dB)
RG preamp set to: 95 dB (the player will turn up the volume for 1 dB)
RG preamp set to: 80 dB (the player will turn down the volume for 14 dB)

It makes perfect sense to me not to be able to scan RG according to the user-specified reference value, because that would mean that some tracks scanned at 89 dB will be quieter than other equally loud tracks scanned at 95 dB reference value, and that would ruin the whole concept of ReplayGain.

This post has been edited by jeremija: Nov 29 2009, 10:07

[kwanbis]

So basically the thing is that the value on the column is the value defined as the playback value, and not the replaygain tool value, which are both different.

[lvqcl]

So basically the thing is that the value on the column is the value defined as the playback value, and not the replaygain tool value, which are both different.

What value on what column? If you mean "Target MP3 alteration volume level" then it has nothing to do with playback or RG calculation.

[kwanbis]

I have a custom column with this value: %__Replaygain_track_gain%

On second thoughts, if i change the slider target on general foobar2k playback options, shouldn't the column adjust?

This post has been edited by kwanbis: Nov 29 2009, 21:39

[shakey_snake]

no.

[kwanbis]

ReplayGain value is a value that "adjust" the volume of the songs, to more or less have all the same loudness.

So, there is a general Gain value (GGV) on fb2k, for songs with replaygain value, and those without.

There is also the replaygain scanner that analyzes the files, and calculates the gain adjustment (+/-) according to the replaygain target (RGT)

Now, i have created a column with thes value of %__Replaygain_track_gain% which should show, if i'm correct, the value calculated by the replaygain scanner to reach the replaygain scanners's target value, is it correct?

If it is, no matter what value y put as the target on the replaygain scanner, that that column shows the same value.

So i went to the general gain value, and also changed it from 89 to 95, but the column still shows the same values.

So, i'm probably missing something, but it is very confusing, as changing either or both of the gain values options in fb2k, have no visual consequences on the column.

What i'm missing?

[Case]

The target value for scanner is always 89 dB. The metadata you see in files is always relative to this. You will not see any different numbers for your files no matter what setting you adjust.

[kwanbis]

The target value for scanner is always 89 dB. The metadata you see in files is always relative to this. You will not see any different numbers for your files no matter what setting you adjust.

So what are this 2 options for?

[lvqcl]

1) To adjust volume level at playback time (It's like volume slider).

2) If you want fb2k to alter mp3 data (just like MP3Gain.exe does it) -- you can set target loudness level of these MP3 files.

[kwanbis]

The questions is, no matter what values i change on BOTH gain options on fb2k, the column shows always the same value.

[shakey_snake]

Sure, because those columns show the values as stored in the file tags, which are always in reference to 89db regardless of where the playback or mp3 alteration settings are set.

The real question is: why is this so hard to figure out?

It would be just like if your file was tagged "The Beatles" but your playlist column was $swapprefix(%artist%). What do you think the properties dialog shows? Tada! the actual value in the tag, not the value adjusted for display/sorting.

This post has been edited by shakey_snake: Nov 30 2009, 00:13

[kode54]

And if we had a $function() to adjust ReplayGain for current playback settings, then anything that supports it would have to refresh every time the configuration is changed. That would mean a callback notification just so you can have a visual display of the current ReplayGain correction that also factors in the playback volume adjustment. I doubt that will ever happen.

[kwanbis]

Sure, because those columns show the values as stored in the file tags, which are always in reference to 89db regardless of where the playback or mp3 alteration settings are set.

But the values stored on on the file tags, are the ones calculated by the replaygain scanner, to which i have told to use 95dB, and not 89.

So, if when i originally do the replaygain scann, the target was 89, and the value was, lets say -5db, after running the replaygain scann, but with target set at 95dB, the value should be -1, not still -5.