What are HE-AAC and LC-AAC?
Both are different profiles of the MPEG4 AAC standard. LC means “low complexity” and HE means “high efficiency”. HE-AAC is also called AAC SBR/AAC+/aacplus, etc. Note that HE-AAC is meant to be used for low bitrate encoding and it is great for multichannel files (smaller filesize). For HE-AAC files, a HE capable decoder is required as well, see Q6. If you want to see comparison with other popular audio codecs at 64kbps, look here (Thanks to rjamorim ) More technically, HE-AAC is the combination of AAC and SBR. SBR stands for Spectral Band Replication. The point of SBR is to encode at low bitrate the entire frequency range without introducing additional artifacts. Traditionally, at low bitrates, audio codecs had the choice of reducing the frequency range and downsampling (see the MP3 FAQ #7) or introducing unpleasant audio artifacts. SBR fixes this problem by leaving the underlying codec to code the low range of frequencies, and the SBR decoder generates the high range frequencies throu
