Taking from a useful post from KMPlayer forum. I’m getting a few problem playing RealMedia files using the KMPlayer default settings. Sometimes after playing a while, the video and audio doesn’t sync properly.
Just posting this for anyone having any trouble getting realmedia files like .ra, .rm, .rmvb to play in kmplayer,here is a good solution for that. It requires no installation of any files, which is nice in keeping employer portable. Download this zip file from http://cdn.kmplayer.com/KMP/Download/codec/rmkmplayer.zip and use your favourite zip file extraction program to extract the files from the folder. You should have 5 files, cook.dll, drv23260.dll, drv33260.dll, drv43260.dll, pncrt.dll , and one folder with the file RealMediaSplitter.ax.
Close employer if it is open. Next, copy or move these files and the folder with file to your main employer directory which depending on your installation type is usually located in windows main program files directory. Next, open KMPloyer, and if not already selected, you should check the “real audio (needs real engine)” option located in kmplayer’s main menu (access by right clicking in player window), options, preferences, internal audio decoder. For best results, also have libcodec decode the video. In version 184.108.40.206 R2, this is located in main menu, options, preferences, internal video decoder. Next to realvideo, select Libcodec.
Also, in main menu, options, preferences, select splitter. Next to real media, select Gabest RM Splitter (RealMediaSplitter.ax). Now navigate to custom filter manager and click add external filter. Navigate to the folder named “filters” (which you just put in employer main directory) next click on RealMediaSplitter.ax and click open. Now you should have in custom filter manager 4 new filters: RealMedia Splitter, RealMedia Source, RealVideo Decoder, and RealAudio Decoder. For each one, priority settings, click “Use forcibly”. Close the preferences window. Now you should be able to play any realmedia files without major problems.