Install third party codecs on your Manjaro for maximum compatibility with video players (should be able to open and play almost any video or audio file).
First install codecs if you need:
$ sudo pacman -S a52dec faac faad2 flac jasper lame libdca libdv libmad libmpeg2 libtheora libvorbis libxv opus wavpack x264 xvidcore
Second install video player:
$ sudo pacman -S vlc
Third install audio player:
$ sudo pacman -S audacious