macos: Add Apple AAC encoder element
Requires !6223 (merged) and !6320 (merged)
Adds atenc
, currently supporting AAC-LC audio at up to 7.1. CBR/VBR are supported and come with necessary knobs for control (bitrate/quality).
Adding LD, HE-AAC and HE-AAC-v2 should be relatively simple in the future, the problem from my testing is that for those formats the AudioSpecificConfig is a bit different and parsing fails, which sometimes causes no output or wrong channel configurations. So leaving AAC-LC only for now.
Edited by Piotr Brzeziński