When comparing SMPlayer vs qmmp, the Slant community recommends SMPlayer for most people. In the question“What are the best media players for UNIX-like systems?” SMPlayer is ranked 4th while qmmp is ranked 12th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Intergrated Subtitle download
Pro Faster than VLC in some cases
Pro Uses mplayer 2 and mpv as engines
Pro Offers some skinning options
Qmmp allows the user to drastically change its look via skins. It can use Winamp and Xmms skins, as well as a list of 12 skins made specifically for qmmp that can be found here.
Pro Small single-window interface
Unlike more popular players that draw a huge window taking up the entire screen, with tons of knobs and menus popping out in new windows, qmmp gives you a single tiny window (that looks pretty much the same as Winamp used to look) with the basic controls and the playlist. The rest is available through a menu.
Pro Lightweight and supports almost all formats
Pro Plugin based
You can extend it with plugins.
Pro Qt-App
No matter what OS or desktop you use Qmmp will integrate well
Pro Clean and simple interface
Pro Depends on libaries
It depends on libaries instead of big fat toolkits like gstreamer.