RMVB (RealMedia Variable Bitrate) is a variable bitrate extension of the RealMedia multimedia container format developed by RealNetworks. As opposed to the more common RealMedia container, which holds streaming media encoded at a constant bitrate, RMVB is typically used for multimedia content stored locally.
You can use Free Video Converter as RMVB converter to convert video to RMVB, AVI to RMVB, MPG to RMVB, MP4 to RMVB, MOV to RMVB, WMV to RMVB and FLV to RMVB.
To convert DVD to RMVB you can use Need4 Video Converter.
To convert AVI, MPG, MP4, MOV, WMV or FLV video to RMVB follow these simple steps:


Open Free Video Converter and add a video file by clicking the File button. In the dialog window opened select the necessary video file and then click Open. The file will be added to the file list below.

To convert AVI, MPG, MP4, MOV, WMV or FLV video to RMVB in the file list select the files you want to convert so they are highlighted. Open the Output format list, choose General Video, then select the Best Quality Download preset, and adjust the output video quality level if necessary.

In the Save as field type in the name for the output video file. In the Save to field specify the folder on your PC where to store converted videos.
Specify additional options:
Overwrite existing files - check it to replace existing RMVB files with the same name in the output folder with just created files;
Open output folder when done - check it to open the output folder after the conversion is finished;
Shutdown when done - check it, and the program will be automatically closed after the conversion is completed.

If you want to convert a fragment of your video, click the Edit button
next to the necessary video file in the list. In the window opened drag the left marker to the start of a desired video episode and the right marker to the end of it.

After you have set up all the settings, make sure that the necessary video is checked in the file list and click the Convert button to start converting your AVI, MPG, MP4, MOV, WMV or FLV video to RMVB.
When video to RMVB conversion is completed, you can get converted videos in the output folder.
To convert DVD to RMVB you can use Need4 Video Converter.