HydrogenAudio

Lossy Audio Compression => MP3 => MP3 - General => Topic started by: AliceWonder on 2012-08-27 10:14:38

Title: ReplayGain and iPod
Post by: AliceWonder on 2012-08-27 10:14:38
Just acquired an iPod Touch.

Quickly found myself adjust the volume. Seems iOS doesn't support ReplayGain but uses it's own system, SoundCheck.

The ReplayGain tags I have on my mp3 files are set by lame.

It looks like http://www.vdberg.org/~richard/rg2sc.html (http://www.vdberg.org/~richard/rg2sc.html) might do the trick (I transcode everything from flac in Linux) but I'm out of town at the moment.

Thought is have my shell script do flac -> lame as it always does, applying the ReplayGain, and then run rg2sc perl script on the result so they play at right volume in iOS.

But I just want to ask if there's a better (also free) solution out there. I don't have a perl environment on my Windows laptop so I can't even really try the script.
I definitely want something that works from *nix cli.

-=-

And am I correct that I will need to disable SoundCheck in iTunes or it will rewrite them every time I play a song in iTunes on my laptop?
Title: ReplayGain and iPod
Post by: skamp on 2012-08-27 13:11:01
"caudec (http://caudec.googlecode.com/) -G album *.mp3" will apply album gain (use 'track' if you want track gain) to your MP3 files, using mp3gain. It will work everywhere, but I don't know if you want that. No soundcheck required, and it will prevent the iPod's EQ presets from clipping.
Title: ReplayGain and iPod
Post by: db1989 on 2012-08-27 13:43:46
And, of course, you could use standalone MP3gain if you would also like to normalise existing MP3 files (rather than transcodes, as handled by caudec).

Edit: stuff about rg2sc was here, before I realised you’ve already seen it  I guess MP3gain might seem easier, depending on your opinion. Or you can invoke rg2sc via MP3tag, but that would require using Wine. Perhaps there is another frontend that can manage rg2sc natively on Linux.
Title: ReplayGain and iPod
Post by: skamp on 2012-08-27 14:03:08
And, of course, you could use standalone MP3gain if you would also like to normalise existing MP3 files (rather than transcodes, as handled by caudec).


That command line doesn't transcode, it just computes and applies gain to existing MP3 files in parallel. It runs much faster than standalone mp3gain.
Title: ReplayGain and iPod
Post by: db1989 on 2012-08-27 14:35:44
My mistake – thanks for the correction!
Title: ReplayGain and iPod
Post by: AliceWonder on 2012-08-27 18:44:26
"caudec (http://caudec.googlecode.com/) -G album *.mp3" will apply album gain (use 'track' if you want track gain) to your MP3 files, using mp3gain. It will work everywhere, but I don't know if you want that. No soundcheck required, and it will prevent the iPod's EQ presets from clipping.


That looks like the way to go, thanks!

Reading the page, it looks like at least for some processes it uses sox.
I assume sox is not involved in this command?

My sox is CentOS build and lacks mp3 support, I could rebuild the rpm if I needed (and maybe will, but I rarely use sox for anything mp3 anyway).
Title: ReplayGain and iPod
Post by: skamp on 2012-08-28 06:23:33
I assume sox is not involved in this command?


It is not. Caudec only uses SoX for resampling while transcoding ("caudec -r cd -c flac" for instance), which isn't the case here. Also, it's only used on decoded WAV files, so there's no need for MP3 support.