Add feature to selectively force transcoding

[jpnassau 0]

Hello Devs,

I've noticed that more media is direct streaming or direct playing which I think is wonderful; so long as I'm on my internal network. I've been seeing media attempting to direct play/stream to devices outside my network instead of transcoding. For a small 700MB file that's fine, but I am seeing problems when it attempts this with 28GB+ HD files. If I remember correctly Emby should "know" that it should transcode, but in my testing I saw it attempt to direct play to the Android app. While I would love for that to work, it just doesn't. Can a toggle be added or enabled to force Emby server to transcode certain files? I usually only see issues with certain files so selective would be fine for the few cases it seems necessary.