Sky Sports Golf on YouTube - pixellation

So it's an encode or compression issue introduced somewhere in the chain between the camera, the high speed radio networks installed at the event, the satellite links, the host broadcaster (e.g. CBS or whoever their contractor is), more satellite and internet links to regional broadcasters (e.g. Sky) and who has ultimately delivered the stream to YouTube, which might or might not be Sky. There are video encode/decode/transcode steps across all those links where errors can be introduced. The stream used for satellite broadcast won't be the same for YouTube upload so observing differences between internet and set-top-box are to be expected.

I don't think it's possible to pin point the problem any further but these type of problems are more likely video feed issues at the event itself.