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* MPEG-4 HE-AAC ( High Efficiency Advanced Audio Coding ).

AAC is a perceptual coder suited for voice and music and the High Efficiency is an optional extension for reconstruction of high frequencies ( SBR: spectral bandwidth replication ) and stereo image ( PS: Parametric Stereo ).

24 kHz or 12 kHz sampling frequencies can be used for core AAC ( no SBR ) which correspond respectively to 48 kHz and 24 kHz when using SBR oversampling.