OptimFROG
OptimFROG is a proprietary lossless audio data compression codec developed by Florin Ghido. OptimFROG is optimized for very high compression ratios, even for the price of slower encoding and decoding.
OptimFROG DualStream
OptimFROG DualStream is a lossy codec, aimed to fill gap between perceptual coding and lossless coding. OptimFROG DualStream has an option to produce a correction file. This file can be used, in combination with the main lossy-encoded file, for lossless decoding.
This correction feature is also offered by WavPack and MPEG-4 SLS.
Technical details
Metadata
Both OptimFROG file formats use APEv2 tags to store the metadata.
External links