Sorry, no Apple products here.
Ya, i thought the same thing Andrew.
But EOS called the same line. Somewhere between that call and JRiver.
Results in two separator results. TranscodingReader vs RespondToFileRequest.
Basically the video has to be perfect. mp4, video codec, audio codec. For JRiver to not transcode.
I'm not sure on resolution. I also don't know about number of video audio channels. I think multiple channel will also result in transcoding.