Animation, audio, and video. This compression scheme includes its own file format. It is a type of delta modulation (differential) compression and hence very efficient, but not useful for nonlinear editing applications. Compression ratios are up to 200:1, lossy but acceptable. There are three layers of MPEG1 encoding of increasing complexity, each layer with its own format. Layer I is fast with typically a 4:1 reduction in data rate with a 32-band filter bank, but offers less compression for comparable quality. Layer II (.MP2 files) is a popular compromise for use with audio files with ratios of 5:1 to 12:1, retaining much of the original sound file’s quality by employing more complex spectral analysis. At a ratio of 8:1, CD-rate audio exhibits little audible loss. Layer III takes longer to compress, but offers higher ratios while retaining much of the audio quality by varying filter bank bandwidths to better simulate the critical bands in human hearing as well as some nonlinear quantizing to increase the efficiency of the data reduction. See MPEG-2, MPEG-3, MPEG-4, DLS-2.