What is Scale Factor Edit?
Sony introduced Scale Factor Edit in 1999 (the first machine was the DHC-MD575 bookshelf system). Scale factor edit is a function that changes the volume level of previously recorded audio by adjusting all the scale factors in each soundgroup. Users can adjust a whole track’s level, or taper the beginning and ending of tracks. This can be used conveniently, for example, to equalize the volume of tracks recorded at different levels or to soften abrupt changes in level at track boundaries. The Scale Factor Edit function modifies audio data on the disc in a completely backward compatible way, any SF editing will be revealed in subsequent playback on all MD equipment. The MJ Magazine MDS-JA3ES article provides a good basis for understanding how this feature works. ATRAC (and other transform audio coders) store audio in the frequency domain. The samples are stored as floating point numbers, with an exponent and a mantissa. The so-called Scale Factor is the exponent, which is stored in 6 bit
