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unusual facts about audio compression


Audio compression

Dynamic range compression, also called audio level compression, in which the dynamic range, the difference between loud and quiet, of an audio waveform is reduced


Pre-echo

It occurs in transform-based audio compression algorithms – typically based on the modified discrete cosine transform (MDCT) – such as MP3, MPEG-4 AAC, and Vorbis, and is due to quantization noise being spread over the entire transform-window of the codec.


see also

Leveler

A leveler performs an audio process similar to compression, which is used to reduce the dynamic range of a signal, so that the quietest portion of the signal is loud enough to hear and the loudest portion is not too loud.

MP4 player

Fuzhou Rockchip Electronics's video processing Rockchip has been incorporated into many MP4 players, supporting AVI with no B frames in MPEG-4 Part 2 (not Part 14), while MP2 audio compression is used.