Hi @Dave_Love1, I double-checked with the engineers and they confirmed that any RTMP encoder will do the trick for sending audio only to Wowza. Shoutcast and Icecast are an option, but not the only options.
For RTMP encoders, Wowza handles incoming audio only files and live streams the same as audio + video. Wowza Streaming Engine media server software can transcode only the audio portion of the stream. If your RTMP source stream includes video, it’s ignored by the Engine Transcoder when you use our audio-only tempate.
(As far as a direct RTMP encoder straight to Wowza by default, we used to have our own device we sold that did that, but we don’t offer that anymore, but again any RTMP encoder will work fine.)
Here are the docs you would need for RTMP encoder and audio only transcoder for AAC playback: