audiozip is a GPLed package for zipping audio files a little better. The audiozipping method relies on this experimental fact: in many "useful" and "musical" cases, the wave form is in some way "continuous", that is the difference between a sample and the previous one (that is, d(n) = S(n) - S(n-1)) are often small.
Bonk is an audio compression program that operates in both lossy and lossless modes. The compression method Bonk uses is quite simple compared to other lossy formats (such as MP3), and is based on speech compression techniques. It is nevertheless capable of producing a high compression ratio while maintaining good sound quality.
CELT audio codec
CELT (Code-Excited Lapped Transform) is an ultra-low delay audio codec designed for realtime transmission of high quality speech and audio. This is meant to close the gap between traditional speech codecs (such as Speex) and traditional audio codecs (such as Vorbis).
a Gnustep front-end that will allow to extract tracks from audio-cd and encod them in the compression audio format ( ogg vorbis, etc ...) wanted
FAAC is an Advanced Audio Coder (MPEG2-AAC, MPEG4-AAC). The goal of FAAC is to explore the possibilities of AAC and exceed the quality of the currently best MP3 encoders.
FLAC stands for Free Lossless Audio Codec. Grossly oversimplified, FLAC is similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. The FLAC project consists of: the stream format, reference encoders and decoders in library form, flac, a command-line program to encode and decode FLAC files, metaflac, a command-line metadata editor for FLAC files, and input plugins for various music players.
A lossless WAV file compressor. Kexis' main goal is to develop prediction and encoding schemes to minimize compressed file size. Kexis strives to be the premier lossless sound encoder.
La is a Lossless Audio compression program. That is, in contrast to formats such as mp3, it reduces the size of music without affecting the quality, as the uncompressed signal is exactly identical to the original. However, the compression ratio is thus far lower than that for .mp3 files - you can expect around 50%, worse for heavier music and better for classical etc.
MP1E is an MPEG1 encoder based on ffmpeg with a lot of optimizations for SSE, MMX.
OptimFROG is a lossless audio compression program. OptimFROG obtains asymptotically the best lossless audio compression ratios. It has Windows and Linux versions, fully featured input plug-ins for the foobar2000, Winamp2, Winamp3, dBpowerAMP, XMPlay and XMMS audio players (with bitstream error resilience, ID3v1.1 and APEv2 read tagging support), optimal support for all integer PCM wave formats up to 32 bits and an extensible streamable (error tolerant) compressed format.
rip-utils is a comprehensive commandline toolkit for ripping, encoding, tagging, organizing, compiling and otherwise managing audio archives. Each utility participates in a common framework that allows commodity tools (such as file browsers, multimedia players and streaming servers) to access your digital catalog simply and effectively.
Shorten is an established low complexity waveform coder. It is fast and has low memory usage and thus is suitable for stand alone or embedded operation for a wide range of audio-like signals. Shorten has two basic modes of operation: lossless: The decompressed file is exactly the same as the original. Typically a factor of two compression is obtained for 16 bit audio. lossy: The compression may be specified either in terms of an average number of bits per sample, or in terms of an acceptable (perceptually weighted) signal to noise ratio.
Speex is an Open Source/Free Software patent-free audio compression format designed for speech. The Speex Project aims to lower the barrier of entry for voice applications by providing a free alternative to expensive proprietary speech codecs. Moreover, Speex is well-adapted to Internet applications and provides useful features that are not present in most other codecs.
An optimized MPEG-1/2 Layer II audio encoder based upon the ISO demonstration source code.
Xvid (formerly XviD) is an open source MPEG-4 video codec, implementing MPEG-4 Simple Profile, Advanced Simple Profile, and Advanced Video Coding standards.