ATRAC (Adaptive TRansform Acoustic Coding) is an audio compression algorithm used to store information on Minidiscs, developed by Sony. It uses quadrature mirror filters and modified discrete cosine transform to represent encoded audio.
Table of contents |
2 ATRAC LP 3 ATRAC-3 LP-2 4 ATRAC-3 LP-4 |
Two stacked QMF split the signal into 3 parts:
Data rate is 266 Kb/s
Double play time, only mono.
Three stacked QMF split the signal into 4 parts:
Similar to ATRAC-3 LP-2, but 66 kbit/s (half the data rate of ATRAC-3 LP-2).
Low quality, similar to MP3 at 80...96 kbit/s.
see also: Lossy data compression, MP3ATRAC SP
No joint stereo encoding.ATRAC LP
ATRAC-3 LP-2
Joint stereo encoding.
132 kbit/s (yes, 15% below ATRAC SP/2)ATRAC-3 LP-4