Cathar vs Perfect Declipper

Cathar is a free audio restoration toolkit for Linux and macOS, with tools to clean, enhance, and level recordings. It accepts WAV, MP3, FLAC, OGG, and M4A files, along with audio tracks inside MP4 and MKV video, and writes WAV, FLAC, or AIFF according to the output filename extension. Restoration options include denoising, de-humming, de-winding, de-clicking, de-clipping, de-reverberation, spectral repair, de-plosive processing, and rustle removal. Enhancement tools handle de-essing, breath removal, voice isolation, and bandwidth extension; loudness and peak normalization prepare delivery levels. The Rust toolkit uses inspectable and tunable DSP stages. Effects can run through the Rust crate or as command-line steps in a media pipeline. An optional machine-learning feature adds a deterministic GRU denoiser with safetensors weights. Optional terminal tools provide an audio player and spectrogram viewer. Cathar is licensed under Apache 2.0 or MIT, and its latest listed release is v0.8.0; the project describes itself as pre-1.0.

Perfect Declipper is a Windows audio-repair plugin for recordings damaged by excessive loudness and clipping. It calculates missing clipped information from the data that remains, and can restore clipped audio and some dynamics. Thimeo says results can in many cases be indistinguishable from an unclipped original, while also explaining that lost data makes perfect reconstruction impossible and that several reconstructions may be equally good. Windows downloads include VST2, VST3, and Winamp/DSP plugins. Listed hosts and applications include Adobe Audition, Audacity, Cubase, Cakewalk Sonar, FL Studio, PlayoutONE, Winamp, RadioBOSS, and AIMP. The Windows build is listed for Windows XP SP3, Vista, 7, 8, 10, and 11. A Perfect Declipper plan costs €100 as a one-time purchase, with an optional Delossifier add-on for €130. Licenses last for life and include updates, though new features may cost extra.