[SOLVED] Replaygained Ogg tracks sound quieter than MP3 ones

[breversa]

Hello again,

As an opensource enthousiast, I've always been using Ogg-capable audio players. I used to have a european Samsung YP-U2, which was almost the perfect player (Ogg-capable, light and tiny, mechanical keys that can be felt by touch alone, huge battery life, good capacity, easy collection navigation ,etc.), but had sadly no Replaygain support, which is why I got a Sansa Fuze that I loaded with Rockbox (I'm using r22777-090921 right now).

However, I feel that my Ogg tracks play noticeably quieter than MP3 ones, although all of them should be properly replaygained (they all play at same volume with Amarok 1.4.10 + amarok_replaygain.py script on Mandriva Linux 2009 Spring).

So, here are my questions :
1- How can I make sure my tracks are properly replaygained ?

2- Assuming they are, how can I make sure Rockbox interprets properly the Replaygain tags ?

3- what else can I do/check to achieve "consistent" playback ?

Regards,
breversa

[Lear]

1 - I check for ReplayGain tags, but for MP3 that isn't reliable (it can be applied to the audio data, so there are no tags). Make sure the tags are in ID3 format, not APE (Rockbox doesn't support APE tags for MP3 files).

2 - Go to the "Show Track info..." screen. It shows how Rockbox interprets the ReplayGain values, if it found any.

[breversa]

Hello Lear, and thanks for your quick reply.

1- According to the mp3gain website FAQ (http://mp3gain.sourceforge.net/faq.php#tagprobs):

MP3Gain stores "Analysis" and "Undo" information in special tags inside the mp3 file itself. These tags are in the APEv2 format. APEv2 tags are carefully designed to not interfere with other tag formats, such as the popular ID3v1 format.

That would explain why  Rockbow can't apply any Replaygain correction to my mp3s.

However, according the the man page :

mp3gain does not just do peak normalization, as many normalizers do. Instead, it does some statistical analysis to determine how loud
       the file actually sounds to the human ear. Also, the changes mp3gain makes are completely lossless. There is no quality  lost  in  the
       change  because  the  program  adjusts the mp3 file directly, without decoding and re-encoding. Also, this works with all mp3 players,
       i.e. no support for a special tag or something similar is required.

Does that mean that all mp3 players can read APE tags ? o_O
Anybody know how to convert APE tags to ID3 ?


2- I checked, and of course, mp3gained files do not show any Replaygain tag. You were right...

[saratoga]

Rockbox won't read APEv2 tags, so you need to put the info in ID3 tags.  LAME does this automatically, and most replaygain software can as well (foobar2000 for instance).

[Lear]

Does that mean that all mp3 players can read APE tags ? o_O

No. If mp3gain adjusts the file directly, it will work with all players (including Rockbox, though it will then apply track or album gain). As I recall it, mp3gain can be configured to only write tags, in which case it wouldn't work with Rockbox.

Anybody know how to convert APE tags to ID3 ?

According to the mp3gain sources, you can tell it to write ID3v2 tags instead of APE tags. Haven't tried it myself though.

[breversa]

Yup, that's looks right : mp3gain v1.5.1 allows to write either ID3 or APE (default setting) tags. Since my version is 1.4.6 (and no more recent RPM available), I think I'm gonna compile it from source and see the results...

I'll keep you informed, of course.

EDIT :
Yay, problem solved !

The issue was indeed with mp3gain v1.4.6 storing Replaygain info in APE tags instead of ID3 tags.

I corrected it by using the latest mp3gain v1.5.1 (downloaded and compiled from http://sourceforge.net/projects/mp3gain/files/mp3gain/1.5.1/mp3gain-1_5_1-src.zip/download), and using the -s i option.

Exercept from mp3gain -h :

Code: [Select]

mp3gain version 1.5.1
copyright(c) 2001-2009 by Glen Sawyer
uses mpglib, which can be found at http://www.mpg123.de
Usage: mp3gain [options] <infile> [<infile 2> ...]
options:
[...]
-s i - use ID3v2 tag for MP3 gain info
-s a - use APE tag for MP3 gain info (default)

Now my reaplygained mp3 sound as loud as my Ogg ones. Thank you all (esp. Lear) !