For new users: PotPlayer is an excellent multimedia player for Windows, DirectShow based.
The player was originally made with the code of the great MPC player by a very good korean developer, but as now (2020) PotPlayer has a stable development while MPC-HC is in maintenance mode, with just some small bug fixes.
Respect to MPC-HC or MPC-BE the korean player has much more settings and functions, faster and more precise seeking, timeline preview like YouTube that works very well, much better than MPC-BE.
The streaming of Internet videos is more reliable than MPC-HC or MPC-BE because PotPlayer by default use its own splitter and audio-video decoders. They're FFMPEG based like LAV Filters. But LAV filters are more optimized for disk content, not streaming.
Attention: as for April 2020 PotPlayer try to install unwanted PUP program during the set-up, but You can (and should) just click on ''Refuse' and everything is fine.
Zoom Player is a DirectShow 32 bit only (no 64 bit version yet..) Windows player; it's reliable, quite fast, with really few bugs, works perfectly with madVR (high quality video renderer) and MPC Wasapi Audio renderer.
The menu is rich of options (in a positive way), in advanced mode it's probably one of the players with more possibilities of real custom settings (ex. Zoom Player can change the Pixel Aspect Ratio of the display in a very precise way, not many players have this function as for 2019).
IMHO the GUI (graphic user interface) could be a bit improved, but it's really a minor point. All in all a very good video player.
For new users: KMPlayer was made originally with the code of MPC and FFDSHOW, but when the developer sold the software to Pandora TV, slowly it became a useless video player.
It's full of big and small bugs, the interface and settings refer to Windows 2000 in a bad way, old filters, old plugins no more used, stutter and jitter, audio and video out of sync, a mess. madVR is not well integrated.
Also, the 32 bit version is no more recommended from the KMPlayer team itself on their forum 'cause is full of unwanted ads, also while playing video in windowed mode!
They advice to use the 64 bit version, which is a clone of MPC-HC, with the same options and very similar GUI.
So, my advice is: please don't use this software, please prefer capable video players like MPC-HC or MPC-BE or Zoom Player or JRiver, made by honest and competent developers.