VLC MEDIA PLAYER is best. This is one of the best players in which all types of video we can play.
It works better in any type of extensions files like MKV, MP4, 3GP, MPEG, MOV, MPEG4, VAT, DAT etc
We can record video according to our requirement into it. Also, it has the facility of clicking snapshot of any memorable event, just by clicking we get the snapshot of the video
almost all kinds of video file formats, including rare file formats, without installing external codecs. The VLC player is an ideal replacement for even iTunes.
Now I am using VLC media player on my smartphone and also in my computer.
Features
video player
audio player
audio management
MKV playback
FLAC playback
Subtitles downloader
subtitles
audio.
Harmful, in what sense?
VLC is open source and free, although it takes a lot of memory(RAM) compared to other players, its my favourite.
from a programming perspective, it takes more RAM just to give you additional features and take less processor time.