No, they are two different applications. MPlayer is a multimedia player developed initially for Linux and then ported to other operating systems. It's very good, it plays almost every everything, and it has for instance a lot of filters and so on. But most users may find it hard to use.
Fortunately, MPlayer can work together with another application (the video window can be embedded in another application's GUI, it obeys commands sent by the application). So SMPlayer is just a front-end which uses MPlayer to actually play the videos.
SMPlayer is the window you see, the menus, the preferences dialog... (along with other things you don't see, like functions to control MPlayer). But SMPlayer knows nothing about playing files. It doesn't even know what a codec is. MPlayer on the other hand, opens the files, decodes them, displays the video and plays the audio. Subtitles are also read, parsed and displayed on screen by MPlayer.
MPlayer2 is a fork of MPlayer. MPlayer2 offers several improvements and features over MPlayer and is compatible with SMPlayer.
SMPlayer is being developed by using Qt, which is a C++ library that allows cross-platform development. The same source code can be compiled on Windows, Linux and Mac OS. More info: http://qt.nokia.com/products/.
In the SMPlayer Drive preferences (Options - Preferences - Drives), enable the "Enable DVD menus (Experimental)" option and set your DVD drive. This feature requires a recent build of MPlayer compiled with libdvdnav support.
MPlayer has several output drivers, for video and sound. SMPlayer allows you to select the one you want among all of them (Preferences -> General -> Video/Audio).
For video it's recommended that you use xv (Linux) or directx (Windows). They use hardware acceleration and give the best performance. The inconvenience about directx for Windows Vista & later users is that it disables Aero.
x11 and directx:noaccel are drivers without hardware acceleration. They give the worst performance. Moreover directx:noaccel gives a bad quality in fullscreen mode.
gl and gl2 will use 3D acceleration from the graphic card. They will give better performance than directx:noaccel and x11 but no so much as directx or xv. gl/gl2 can be useful for Windows Vista & later users.
For sound, you should usually use alsa in Linux. I don't like esd or arts, they use to use more CPU.
In Windows the sound drivers are dsound and win32. I read that dsound can cause sometimes audio-video sync problems. If you notice that problem try win32 instead.
Other drivers allows you to save the video as image files or write the sound to the disk. These drivers are not officially supported by SMPlayer. Use them only if you know what you're doing.
You didn't choose a folder for storing the screenshots. Do it in Preferences -> General, and the screenshot option will be enabled.
With some formats (ike mp4 or ogm), MPlayer can't change the audio track at runtime. By unchecking the option "Fast audio track switching" (Preferences -> Performance) you'll be able to change the audio in those formats.
Preferences -> Keyboard and mouse. You'll be able to change most key shortcuts.
MPlayer can player most common formats "out of the box". But for codecs that haven't been yet implemented natively, it's necessary to install a package with binary codecs. You can get it from the MPlayer download page.
On Windows, install the codecs in the mplayer\codecs subdirectory. On Linux distros the package may be available as a regular package, maybe with the name of w32codecs or something like that.
If the option "Show icon in system tray" (in menu Options) is not checked, then yes, the two options do the same: quit the application.
But if that option is enabled, then Open -> Close will just hide the application (and stop the current file), but SMPlayer is still running. Open -> Quit really quits the application, no matter if the system tray icon is enabled or not.
Support for audio CDs was added in version 0.5.18.
Under Windows it's not possible to play audio CDs yet.
Probably MPlayer couldn't play the file. Open the mplayer log (Options -> View logs -> MPlayer), you'll probably find an error message in the latest lines.
On Windows is quite common that some MPlayer builds fail because they have been compiled without support for some feature that SMPlayer tries to use. The error message could give you a clue. If it complains about cache, try disabling the cache in Preferences -> Performance. If it complains about fontconfig, try to use a ttf font instead of a system font.
Some options require to stop the MPlayer process and start it again with new parameters. That's why playing interrupts for a moment.
SMPlayer crashed, but MPlayer is still running. Kill the MPlayer process in the Task Manager.
Anyway if SMPlayer crashes, it's a serious bug that should be fixed. Report it.
I recommend to use at least MPlayer SVN r33216 (from 2011-04-05) or MPlayer2, although a recent version from SVN/git would be better for improved codec support and bugfixes.
SMPlayer will try its best to work with older versions, but some options may not work.
Video filters -> Add black borders
You can add a video filter like expand=:::::4/3 in Preferences -> Advanced -> Options for MPlayer.
Other possibilities:heartbeat-cmd="gnome-screensaver-command -p &>/dev/null"(kde)
heartbeat-cmd="dcop kdesktop KScreensaverIface enable false &>/dev/null && dcop kdesktop KScreensaverIface enable true &>/dev/null"
Please take a look at the MPlayer manpage for more info.
To adjust the font size for the OSD, which displays the time and other messages from MPlayer in the upper-left corner, under Preferences -> Advanced -> Options for MPlayer, in the Options: field, add the following:
-subfont-autoscale 0 -subfont-osd-scale y
Where y is the size to your preference. The default value for -subfont-osd-scale is 20.
The main SMPlayer configuration file is smplayer.ini. Depending on your configuration, individual file settings are saved in smplayer_files.ini (one ini file) or the subdirectory file_settings (multiple ini files). They are located according to your OS:
Linux $HOME/.config/smplayer Windows 2000/XP C:\Documents and Settings\<your_username>\.smplayer Windows Vista/7 C:\Users\<your_username>\.smplayer
You can also see it in the SMPlayer log (Options -> View logs), look for a line like this:
* ini path: '/home/ricardo/.config/smplayer'
smplayer.ini stores the SMPlayer configuration while smplayer_files.ini stores the settings of the files you have played.
Note: In Linux, .config may be hidden by default. Be sure to enable hidden files and folders in your file manager.
When you use directx as video driver (Preferences -> General -> Video) the video can only be displayed on one monitor. If you use instead gl, gl2 or direct3d the video will be displayed in any monitor.
Anyway if you prefer to use directx you can choose the screen which will be display the video in the menu Video -> Screen.
This happens when using directx as video driver (Preferences -> General -> Video). You can change it to gl, gl2 or direct3d.
If you are unable to open files with special or non-English characters, enable Pass short filenames (8+3) to MPlayer under Options -> Preferences -> Advanced to work around this problem.