What is AACGain?
AACGain is an open source audio normalization tool that adjusts the volume of AAC, MP3, Ogg Vorbis, FLAC, WavPack, MP4, M4A, and Apple Lossless (ALAC) audio files. It was created in 2001. It aims to match the loudness of all tracks in an album or collection to the same standard level.
By normalizing the loudness, AACGain makes it easier to set the volume correctly when listening to files encoded in different formats or from different sources. This avoids the need to constantly adjust volume between tracks. It applies ReplayGain adjustment directly to the file metadata.
Key features:
- Free and open source software
- Works on Windows, macOS, and Linux
- Command-line interface
- Analyzes loudness and normalizes volume automatically
- Preserves audio quality when adjusting gain
- Updates tags with ReplayGain information
- Handles a variety of audio formats
- Works well for normalizing albums, compilations
Overall, AACGain makes it easier to achieve consistent volume levels across large audio collections with mixed sources and formats. Its batch processing capabilities are useful for post-processing in audio production and broadcasting.