Of course it's easy to see how the video is encoded. ffmpeg will tell you everything about a video stream's encoding. I assume you're interested in the more difficult question of knowing if a 10-bit 4:2:2 video originated that way or was just upconverted from 8-bit 4:2:0.

To know if video is 8 bits or 10 bits per sample, you need to look in a video scope of some type and see if there are levels intermediate to the 256 levels you'd get with 8 bits. Not all scopes show more than 8 bits, but you can work around that by increasing the contrast to spread them apart. You'll need to be sure the software you're using supports 10 bits throughout the chain. I've done exactly this kind of analysis, to test whether various software supported more than 8 bits. It's a bit complicated and nuanced when you start: you can't trust any part of your software chain to be supporting more than 8 bits. The difficulty in testing this points to the fact that 8 bits is really good enough for many things. You need to work hard to expose the limitations of an 8-bit encoding. You can almost never tell just by looking. It usually requires some kind of manipulation.

There are lots of ways to visualize chroma subsampling, but probably the easiest way is to view the Y, U, and V channels in isolation and see how they compare. The chroma channels will be noticeably softer than the luma channel. You could also downsample and then upsample the chroma channels and compare that to the original channel to see if it's any softer.

thanks for the replies, mediainfo seems to be the best option. Gspot gave me little info instead.