From AMS documentation, I can package vod content as audio-only by appending "audio-only" to url for instance:
http://<ams server ip>/hls-vod/audio-only-aac/vod.m3u8
Similarly I can package live content (single bitrate) as audio-only for instance:
http://<ams server ip>/hls-live/audio-only-aac/livepkgr/_definst_/liveevent/livestream1. m3u8
In my case, I have 3 bitrates being published for a live audio-video event. The variant playlist for this event is created by hls_http module by refering to Manifest.xml.
I could not figure out a way to insert an audio-only stream to this variant playlist created by hls_http module for live stream.
Please let me know if I am missing something because this seems to be a pretty obvious requirement for live streaming to IOS devices.