Real Media Videos with variable bitrate are marked by the extension RMVB.
These represent a special variant of the Real-Media-Container, which uses the extension rm.
The container format developed by RealNetworks typically includes video and audio sources encoded with the proprietary, lossy Real Video or Real Audio compression technology.
RealMedia is primarily used for streamed content, as it allows you to create and send different quality levels of a source material simultaneously. It is especially common in Asia.
Most often resolving problems with opening RMVB files is very simple. Just install an appropriate program that supports such files. All of the listed programs support RMVB files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of RMVB files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate RMVB files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the RealPlayer applications is not on the list, select "Browse" option in order to manually locate the directory where RealPlayer has been installed.
Sometimes problems with opening RMVB files may not lie with the application itself, but can arise due to other causes, such as: