Allow users to customize ffmpeg/x264 options

It'd be pretty simple, and would let users with more powerful processors fine-tune their transcoder settings to achieve higher compression ratios while remaining live.

I'd like to see Plex tune for media type. For example a cartoon with the genre "Animation" might benefit from the ffmpeg -tune=animation option.

I'm gonna bet that a lot of those tuning options don't do a damn thing in the end.

This would be interesting, but I'd also be willing to bet that most users would just fubar it...  

You can currently do this however by directly editing the profile.xml for the device/profile in use.