I've got a video consisting of AVCHD shots that has some slight grain/colour breakup in the highlights/midtones, and it looks fine upon my regular Match Source - High Bitrate H.264 export from Premiere Pro, but as soon as it's uploaded to youtube, this grain is brought out to look terrible. I assume because of the fact that YouTube recompresses everything uploaded.
I've tried Youtube presets, massive bitrates (45), but every time the grain is still made to look incredibly more obvious than in my export. You can see the upload here: https://www.youtube.com/watch?v=Ng6JTPaZ9uc, and it's most notable at 0:00 and 0:15.
Can anyone please advise how I can solve this as soon as possible? I didn't factor these issues happening into the release schedule and would really love to sort it out today.
Issues like this are often due to how YouTube's encoders handles the complexity around certain areas which include gradients and shadows or high contrast edges. You can try uploading a ProRes file but that may not have much impact. It's their encoder at issue. This is why some people still use paid services which allow customized cloud encoding to host their content.