A question about YouTube's deinterlacing

[defbiz]

Is YouTube's deinterlacing algorithm good enough? What method does it use? Whenever I upload videos I just let the platform do the deinterlacing since I don't want to risk a third re-encode in case it looks worse, however from what I see it simply does a quick discard and weave. Should I QTGMC/yadif my videos first before uploading?

[poisondeathray]

You should do it - besides the lower quality, the YT deinterlacing discarding a field won't give your full temporal resolution either (59.94p/50p). Instead you'll get 29.97p/25p half the samples, less smooth motion

[Bwaak]

"Discard and weave"? In my experience, YT just weaves. I am bewildered how they have managed to become the biggest online video hub without decent deinterlacing. I can still see professional videos uploaded by, say, PBS, that show combing. I suppose they just upload their broadcast version without deinterlacing for YouTube.

Deinterlace to 50p/59.94p with at least 720 lines, anything smaller and YT will drop to 25/29.97 even if you encoded it as 50/59.94.