[James Smith]

Thanks John.
Be careful, that the video player you are using is not deinterlacing and the video really has these artifacts and the player is hiding them from you.
I hadn’t thought of that. The 2 software players I’m using are Powerdvd and Splash Lite. It could be they are deinterlacing automatically without me being aware.
[by the way, Splash Lite is a nice free software player for anyone that needs to play .m2ts files].

Maybe Youtube have changed something at their end so that now when they process a video, they no longer remove interlace artifacts….

[James Smith]

Hi John,
The render template has stayed the same: AVCHD 1920×1080 PAL.
The field order was set to Upper field first, so I changed it to ‘None (prorgressive scan)’ as you suggested, but it didn’t make any difference.

“Also make sure that your media is being correctly interpreted as interlaced if it is.”
The media is an .m2ts file from a Panasonic SD 60 which as far as I am aware is interlaced.

“In other words, right-click on an event, go to the Media tab and check that the field order matches the real field order of the media.”
If I understood you correctly, both field orders were set to ‘upper field first’ when I checked just now.

You can see an example of the interlace effects here which are present when there’s movement in the video (You can see them best at full screen 1080):
https://www.youtube.com/watch?v=lI8fQost7w8
The video looks really nice on the software players on my computer, but not so nice on Youtube due to the artefacts.

Funnily enough, as a test, I just re-uploaded an old Sony Vegas video to Youtube I had on my hard disk that I had previously uploaded to Youtube and know displays ok there with no interlace lines. This second time of uploading the same video now has it appearing on Youtube interlaced, suggesting that something’s changed at Youtube’s end, not mine. Is this possible? Or is it some error or misunderstanding at my end?