AAC+) decoder Note: aacPlus v1 is AAC + SBR, aacPlus v2 is AAC + SBR + PS. high efficiency (HE, HE-AAC, aacPlus): uses Spectral Band Replication (SBR) and may use Parametric Stereo (PS).long term prediction (LTP): main profile with forward prediction.sample-rate scalability (SRS): submitted by Sony and reportedly similar to ATRAC/3.main (MAIN): LC profile with backwards prediction.low complexity (LC): reported to be the simplest (Apple iTunes files).Allegedly, each frame stands alone and does not depend on previous frames (whereas many perceptual audio codecs overlap data with the previous frame). Surface details of the format can be found at Wikipedia: Ĭonformance vectors can be obtained here: is a variable bitrate (VBR) block-based codec where each block decodes to 1024 time-domain samples. 3 Packaging/Encapsulation And Setup DataĪAC is a perceptual audio codec which means that it throws away certain information during the compression process, information that has been deemed less important.
0 Comments
Leave a Reply. |