From Hydrogenaudio Knowledgebase
TTA (True Audio) audio codec is a free, simple real-time lossless audio encoder/decoder, based on adaptive prognostic filters which has shown satisfactory results comparing to majority of modern analogs.
 TTA Compressor
- Down to 30-60% lossless audio data compression
- Real-time encoding/decoding algorithm
- Fast decoding and encoding
- Open source code and documentation
- Hardware support
TTA performs lossless compression on multichannel 8, 16 and 24 bit data of the WAV audio files. Being "lossless" means that no data/quality is lost in the compression - when uncompressed, the data will be identical to the original. The compression ratios of TTA depend on the type of music file being compressed, but the compression size will generally range between 30% - 70% of the original. TTA format supports both ID3v1 and ID3v2 information tags.
 The Project
The TTA project provides:
- Free and simple data format
- Plugins for the most popular media players
- TTA DirectShow filters
- Tau Producer - GUI based compressor for Windows
- Set of the C/C++ TTA development libraries