So how does this work out fee/patentwise in the OSS world? I know ffmpeg/libav can play HEVC/x265 streams (or at least mpv can). Can it not encode to HEVC? Or do the fees start to apply when you start distributing content? Or is it like mp3 where fees are only attached to hardware encoders/decoders (which gets all iffy because where do you draw the line between hardware sold for encoding/decoding that has software codecs on it vs general purpose OSes with the same codecs?)

And doesn't Firefox have some special deal with Cisco to use their x264 decoder on the web?