MPEG-4 Advanced Audio Coding Scalable Sampling Rate
<compression, standard, algorithm>
(MPEG-4 AAC SSR) An AAC flavour supporting different qualities for different targets. One stream can contain up to 3 streams for 11.025 kHz (Stream 1), 22.05 (Stream 1 and 2) and 44.1 kHz (all 3 Streams) sampling frequency. Quality is between Low Profile and Main profile. See also JPEG-2000.
Last updated: 2001-12-09
MPEG-4 Advanced Audio Coding Scalable Sampling Rate ♦ MPEG-4 Harmonics, individual lines and noise
Try this search on Wikipedia, Wiktionary, Google, OneLook.