Dynamic Audio Normalizer is a library for advanced audio normalization purposes. It applies a certain amount of gain to the input audio in order to bring its peak magnitude to a target level (e.g. 0 dBFS). However, in contrast to more “simple” normalization algorithms, the Dynamic Audio Normalizer dynamically re-adjusts the gain factor to the input audio. This allows for applying extra gain to the “quiet” sections of the audio while avoiding distortions or clipping the “loud” sections. In other words: The Dynamic Audio Normalizer will “even out” the volume of quiet and loud sections, in the sense that the volume of each section is brought to the same target level. Note, however, that the Dynamic Audio Normalizer achieves this goal without applying “dynamic range compression”. It will retain 100% of the dynamic range within each “local” region of the audio file.

The Dynamic Audio Normalizer is available as a small standalone command-line utility and also as an effect in the SoX audio processor as well as in the FFmpeg audio/video converter. Furthermore, it can be integrated into your favourite DAW (digital audio workstation), as a VST plug-in, or into your favourite media player, as a Winamp plug-in. Last but not least, the “core” library can be integrated into custom applications easily, thanks to a straightforward API (application programming interface). The “native” API is written in C++, but language bindings for C99 Microsoft.NET,  Java,  Python and Pascal are provided.

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github.com/lordmulder/DynamicAudioNormalizer