Express is a basic port of MP3Gain to Mac OS X. It allows you to
analyze or apply track gain to a list of MP3 files. Anyone who has used
the Windows UI for MP3Gain should find this one familiar, as it
was designed to look similar to that version.
It's easy to use. Simply select the files you want to increase or
decrease the volume of, enter the desired loudness, and click Apply
Gain to update your files.
If you are using this program for the first time, please remember to back up your files before trying to modify them with MP3Gain. While the application should work fine for most users, differences between machines could result in problems that only affect a small number of people.
Requires OS X 10.6 Snow Leopard or later. (Pictured running
under Mountain Lion 10.8)
Last updated on February 2nd 2013:
Fixed a reported case of file corruption for certain long path and file names. Added subfolder processing, the ability to prevent clipping, and the ability to undo gain applied to files. Fixed automatic update.
Questions and Answers (Also found in the included Readme file)
What is MP3Gain?
MP3Gain is a tool to increase or decrease the volume of MP3 files
without re-encoding them. This is useful when you have a lot of music
at different volumes, you can use this tool to make everything the same
volume so that you don't need to adjust the volume on your MP3 player
when listening to your music on shuffle.
What does MP3Gain Express do?
This version of MP3Gain only does three things. It can:
What does MP3Gain Express not do?
- Analyze MP3 files and write the volume information to a tag
without changing the audio data itself. This is useful if you have a
player that supports "ReplayGain" tags. (Not iTunes or iPods, so mostly
useless on Mac OS X)
- Apply Gain to MP3 files. This updates the audio data in the files
to apply the new volume directly to them. This is done without re-encoding
the file, so there usually is no loss in audio quality compared to
original data. (I assume that if you make the file loud enough to start
"clipping" that this would count as quality loss. The loudness of
digital audio can be represented within a range of values, and once you
go above the maximum any points above the maximum can only be
represented as the maximum itself. If the "Clipping" column shows Yes
then this situation is occurring. In some cases, depending on how loud
you go, you may not notice it. You can click the "Prevent Clipping"
checkbox to automatically use a lower value if clipping would occur.)
- Undo changes applied to MP3 files, returning them to their original
volume. This will only work if the file has previously had gain applied to it,
and undo has not been performed on the file. The undo feature cannot remove
file corruption in files that were accidentally damaged by the program.
MP3Gain Express omits several features of the original MP3Gain, hence
"Express" tacked onto the name.
Why port MP3Gain to Mac again, even
though a port already existed?
- Album gain is not supported. (All tracks have their volume
adjusted individually, you can't adjust tracks as a group)
- MP3Gain Express does not back up your files for you. As with any
application, there is a chance something could go wrong. If you've
never used the tool before, I suggest backing up your files first to
make sure it works as you intended.
- Versions of Mac OS X older than 10.6 are not supported. If you
want an alternative, try Bery Rinaldo's port which is old and has more
This port was made to fulfill one need that I had. I wanted to increase
the volume of a few tracks I had that were too quiet. I didn't need any
of the other features of the program, so they aren't available in this
port. I started this port a few weeks before Mac OS X 10.7 Lion was
released, and Bery Rinaldo's port had not been updated in over 3 years
so I assumed it was dead. It also wasn't compatible with Snow Leopard
at the time.
I decided to do my own port for two reasons:
- The existing port was a front-end written in AppleScript. Anyone
familiar with my previous work (MultiPatch for example) might be aware
that I prefer to call code natively and not use an external tool to do
the work. I felt that this could benefit from the increased flexibility
of a native application.
- The existing port was bundled with PPC binary at that time, which
would not work on Mac OS X Lion. My intention was to release the port around
the time Lion came out in order to fill that gap.
After I reached the point where it was partially working, it sat
untouched for a few months. By the time I eventually came back to it,
Bery had updated his version with Lion support. I guess the only
advantages of this version are that it would be slightly faster due to
the native MP3Gain integration, and the UI is a bit more modern since
it was designed on Snow Leopard and Lion.
I have not actually used his port, so my comparisons are based on the information
on his website.
Is there a build of the command-line version of MP3Gain available on OS X for power users?
Yes. I am now providing a command-line build of MP3Gain with AACGain support.
This is the command-line version of AACGain 1.9 built for OS X 10.6 or later.
It is based on the 1.9 code from MP3Gain's SVN repository with no changes made.
You can download it here
Will this port be actively maintained
Probably not. MP3Gain itself isn't updated often anymore (Why would it
be? It already does what it was intended to do) and I primarily wrote
it for myself to use once every few years. I listen to my music on
shuffle, so I didn't need Album Gain. If this program ever breaks in a
future version of OS X, I will probably update it just so that there's
always a working port available.
What is the license?
MP3Gain is LGPL. This port is also LGPL. You can probably find more information about that license on Wikipedia.
Where can I get the source code, report bugs, or request features?
There is a project on GitHub for MP3Gain Express where you can check out the current development code for the application, submit your own changes, bug reports, or feature requests. You can find it at https://github.com/Sappharad/mp3gainOSX/
I can be contacted via e-mail at sappharad @ [same thing
as before the @ symbol] .com.