Home » API Reference » Encoding Settings » AAC » Max AAC Profile


:String permalink

API Versions: V1, V2

Parent: outputs

Default: he-aac

Valid Values: aac-lc, he-aac, or he-aac-v2

Compatible Job Types: All

Example: he-aac-v2


The AAC audio codec has several profiles. By default, Zencoder will pick the right profile based on the bitrate and number of channels used: stereo content under 40kbps will use HE-AAC v2 if max-aac-profile is set to "he-aac-v2"; stereo content under 84kbps will use HE-AAC if max-aac-profile is set to "he-aac"; and AAC-LC will be used for higher bitrate content, or if max-aac-profile is set to "aac-lc". "he-aac" is the default value, which means that by default, 0-84kbps will use HE-AAC and 85kbps and up will use AAC-LC.

AAC-LC ("Low Complexity") is the most common AAC profile, and virtually every AAC decoder supports AAC-LC. AAC-LC allows mono and stereo, with sample rates from 8khz-96khz, and high bitrates (>300kbps). Use AAC-LC when encoding stereo content at 80kbps and above or mono content above 40kbps, or when you want to support devices that only play AAC-LC, like the Roku or old iPods.

HE-AAC ("High Efficiency") is a widely supported AAC profile that sounds better than AAC-LC at low bitrates by implementing Spectral Band Replication (SBR). HE-AAC supports mono and stereo content at sample rates of 16khz-48khz and bitrates ranging from 16kbps-128kbps. Most web and mobile decoders support HE-AAC, including Flash, HTML5 (wherever AAC is supported), iPhone, iPad, Android, etc. Use HE-AAC for stereo content below 80, or low bitrate mono content.

HE-AAC v2 is optimized for even more aggressive compression than HE-AAC by adding Parametric Stereo (PS) to HE-AAC. This means that HE-AAC v2 is only suitable for stereo content; mono content can only use HE-AAC. HE-AAC v2 is supported by Flash, HTML5, and some mobile devices (Windows Phone 7, Android). Use HE-AAC v2 for stereo content below 40kbps or so, but not for iOS audio. (Newer iOS devices can play HE-AAC v2 content, but ignore the PS information, resulting in mono content.)

  "input": "s3://zencodertesting/test.mov",
  "outputs": [
      "max_aac_profile": "he-aac-v2"
  <outputs type="array">