![]() ![]() Here is a graph of perceptual audio quality with the 3 codecs. Typically AAC-HE v2 isn't used above 48k and AAC-HE v1 isn't used above 96k. Obviously this isn't a perfect algorithm and some stereo data is lost and not replicated accurately, but it's not too bad.ĪAC-HE is only suitable for bit-rates below 128k. This audio codec is the most efficient audio compression scheme available worldwide and allows for up to three times as. DAB+ DAB+ is More Efficient than DAB DAB+ uses MPEG-4 High Efficiency AAC v2 profile (HE-AAC v2). This was a huge improvement for encoder efficiency as what it does is down-mix the stereo signal to mono, and then use 2-3kbit to store the difference data to replicate the differences in the original stereo signal. If dgavcindex can demux the AAC audio, then I can just play the aac file in Winamp to output a wav. Then in AAC-HE v2 they added in PS (parametric stereo). V1 for AAC-HC added SBR (spectral band replication) which helps to reproduce the higher frequencies with lower bit-rates. AAC-HE is really just the same encoder as AAC-LC except it has additional tricks added to it's algorithm that are used under 128k. Here is a chart showing the AAC profiles:Īs you can see AAC-LC (low complexity) is a subset of the AAC-HE profile. ![]()
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