Free online RMVB to DIVX converter

Older televisions, DVD players, and editing programs may accept DivX video but not RealMedia files. Converting an RMVB recording to a DivX-compatible AVI file can make it usable on that hardware and in software built for MPEG-4 Part 2 video.

What the RMVB format is

RMVB means RealMedia Variable Bitrate. It is a RealNetworks container associated with variable-bitrate RealVideo and RealAudio streams, commonly used by RealPlayer and RealProducer for older streaming distributions, downloads, and video archives.

Variable bitrate encoding assigns more data to complex scenes and less to simple scenes, which can reduce file size at a given quality level. An .rmvb file may contain RealVideo 3, RealVideo 4, or another RealVideo stream with RealAudio or another supported audio format. Modern players and devices support RMVB less consistently than MP4, AVI, or Matroska files.

Renaming .rmvb to .avi or .divx does not convert the streams. The file must be decoded and re-encoded into a compatible video and audio format.

What the DIVX format is

DivX generally refers to MPEG-4 Part 2 video encoded with a DivX-compatible encoder. It is commonly stored in an AVI container and was designed for compact files that could play on older DVD players, televisions, game consoles, and desktop software.

A legacy-compatible output typically contains MPEG-4 Part 2 video with the DIVX FourCC identifier and MP3 audio in an AVI container. The .divx extension may also be used for a DivX Media Format file, so the extension alone does not define the codec, container, or playback capabilities. Compatibility depends on the target device's supported resolution, frame rate, bitrate, MPEG-4 features, and audio format.

How to convert the file

Using the converter on 101convert.com:

1. Open the RMVB-to-DIVX converter and choose the .rmvb file.
2. Select DIVX as the output format when that option is available. If the converter offers AVI with DivX settings instead, choose AVI and verify that the video codec is MPEG-4 Part 2.
3. Start the conversion and download the resulting file when processing finishes.
4. Test the output on the intended player. A file that plays on a computer may still exceed a legacy device's resolution or bitrate limits.

Browser conversion requires uploading the video, so local conversion is preferable for confidential files or very large sources.

Using FFmpeg locally: Install a current FFmpeg build with RealMedia decoding and MPEG-4 video and MP3 audio encoding. In a terminal, run:

ffmpeg -i input.rmvb -c:v mpeg4 -vtag DIVX -q:v 4 -c:a libmp3lame -b:a 128k -f avi output.avi

This command decodes the RMVB streams, encodes MPEG-4 Part 2 video, writes the DIVX FourCC, encodes MP3 audio at 128 kbps, and places both streams in AVI. The MPEG-4 quantizer range uses lower values for higher quality and larger files; try -q:v 2 or -q:v 3 for better preservation and -q:v 6 for a smaller file.

If the receiving program specifically requires a .divx filename, use the same AVI structure with that extension:

ffmpeg -i input.rmvb -c:v mpeg4 -vtag DIVX -q:v 4 -c:a libmp3lame -b:a 128k -f avi output.divx

If FFmpeg reports that it cannot decode the source, use a build with RealVideo and RealAudio support or a desktop converter that explicitly lists RMVB input and DivX or AVI output. A graphical converter should expose the same essential settings: MPEG-4 Part 2 video, AVI output, the DIVX tag, and MP3 audio.

Quality and compatibility limits

Conversion cannot restore detail lost during RMVB compression. Re-encoding introduces another generation of quality loss, so use a lower quantizer when preservation matters and avoid unnecessary resizing or filtering.

For an older standalone player, follow its documented DivX profile. Common restrictions include AVI containers, MPEG-4 Part 2 rather than H.264, MP3 rather than AAC audio, standard-definition dimensions, moderate bitrates, and limited frame rates. Valid AVI structure does not guarantee playback if the video exceeds any of those limits.

Inspect the result with:

ffprobe output.avi

Check for MPEG-4 Part 2 video with a DIVX tag, MP3 audio, and dimensions and frame rate accepted by the target device. Incomplete or damaged RMVB downloads may contain incorrect timestamps and can produce audio synchronization errors; repair or replace the source before encoding when that occurs.