Port of mp3gain to ANSI C

Release: 1.0.5

introduction usage download changes todo contact

Introduction

Mp3gain is a powerful utility to modify the real loudness of MP3 files automatically to one common level. It utilizes the psychoacoustic modell of replaygain to do the loudness analysis. The modifications to the MP3 files are lossless (i.e. without any additional losses) and reversible. See the original homepages for further details.

The modification of the MP3 files is done in place and lossless.

The utility can operate on MPEG 1, MPEG 2 and MPEG 2.5 file Layer 3 only.

Usage

installation

Copy the executable file somewhere to your harddrive. You propably want to use a folder which is listed in your PATH environment.

usage

See command line help for details:

mp3gain /?

remarks

The command line option /p (Preserve original file timestamp) does not work in this port. This was originally implemented using Win32 API calls.

Download

This program is distributed under the terms of the GNU LESSER GENERAL PUBLIC LICENSE.
ZIP file with C source, OS/2 binary and this guide: Version 1.0.5
The source code should compile on any ANSI C compliant C compiler.

There is a OS/2 debug executable available for profiling purposes. Do not execute it unless you read this:
This executable propably will freeze your whole system. I put on my hompage to help to track the bug in OS/2 or the gcc 3.0 environment respectively. This does not affect the regular executable above.

Changes to original distribution

I have changed the RMS window functionality completely. The data is now processed by half overlapping windows of 100ms length, scaled by a Hamming window function.
gain_analysis.c is now renamed to gain_analysis.cpp. This is because the .c version already used C++ syntax extensions. New C/C++ compilers often do not claim about that, but that is not guaranteed.
The code in gain_analysis.c is optimized significantly. The performance improovement is around 100% for the analysis part on my K6-475 using gcc 3.0. Including the MP3 decoder it is around 50%.
All Win32 API call are replaced by their ANSI C pendants, as far as possible.
The functionality to preserve the time stamps of the files is removed.

ToDo

Port of /p functionality to ANSI C (if possible)
Rename mp3gain.c to .cpp: mp3gain.c also uses C++ syntax extensions. So it should be renamed to .cpp, too. However, I had problems with that, so I have not done this so far.

Contact

Suggestions, help, complaints (but not too much:-): mueller@maazl.de

Original location of this page: http://www.maazl.de/project/mp3/mp3gain.html

Please keep in mind that I have only done the porting of this utility. So if you have questions not directly related to the ANSI C or OS/2 porting you should better contact the original author of mp3gain. See introduction for a link.