Some people use mpc-hc for the Yunokami stream, but for me personally it runs in low fps, so I am using mpv instead, which runs at smooth 30fps.

Download mpv from here: https://mpv.srsfckn.biz/

Now let's set up a small config file (not compulsory). We will set up the screenshots settings in it.
You can download my config file from here: https://pomf.pyonpyon.moe/mgfhdc.zip (extract from zip)
You can see two commands already written there:
--screenshot-template=E:\My Videos\Pictures\train\1New\train-%n
--screenshot-jpeg-quality=96
The first command is where to save the screenshots. Change it to the path you want for yourself.
The "train-%n" part is how to name the screenshots. In this case it will name it as "train-number of picture in the folder"
The second command is the quality of picture. I have found 96 to be a satisfactory balance between quality and filesize for me.
While watching the stream press "S" to make a screenshot.

How to run a stream:
Make a shortcut to the mpv.exe file. (right click -> send to -> desktop (create shortcut))
On the shortcut press right click -> properties.
In the "Target:" field at the end of the path after mpv.exe put "rtmp://114.160.7.45/livepkgr/live-cam003" (no quotations marks, also leave a space between mpv.exe and the stream link)
Press Okay and you are done. You can Rename the shortcut to "Yunokami" or whatever if you want to.