Can the transcoder addon transcode vp6 over rtmp, to h.264. I have not been able to successfully do it.
No, sorry, VP6 is not supported (for decode or encode) in the Wowza Transcoder
Video decoding: H.264, MPEG2, MPEG4 Part 2
https://www.wowza.com/docs/how-to-set-up-and-run-wowza-transcoder-for-live-streaming’
Richard