Free online DVR-MS to OPUS converter

Windows Media Center recordings are often stored as DVR-MS files, while modern browsers, voice applications, and media players commonly accept OPUS audio. Converting extracts the recording's audio track and re-encodes it in the OPUS codec, producing a smaller audio-only file.

What the DVR-MS format is

DVR-MS is Microsoft's Digital Video Recording format, an ASF-based container used primarily by Windows Media Center in Windows XP, Vista, and Windows 7. It stores recorded television programs and can contain MPEG-2 video, WMA or other Windows-compatible audio, metadata, captions, and copy-protection information. You may encounter it when opening archived Media Center recordings or files copied from an older Windows television-recording setup.

What the OPUS format is

OPUS is a lossy audio codec normally stored in an Ogg-based file with the .opus extension. It supports speech and music efficiently, works well at low bitrates, and is supported by current browsers, VLC, FFmpeg-based applications, WebRTC software, and many mobile players. It is suitable when the video is no longer needed, especially for speech recordings, podcasts, or compact archives.

How to convert DVR-MS to OPUS

FFmpeg is the most direct desktop method because it can read many DVR-MS recordings and select only their audio stream.

1. Install a current FFmpeg build that includes the libopus encoder.
2. Open a terminal in the folder containing the recording and inspect its streams with ffprobe input.dvr-ms. Identify the desired audio stream if the recording contains more than one.
3. Extract the first audio stream and encode it as OPUS with ffmpeg -i input.dvr-ms -map 0:a:0 -vn -c:a libopus -b:a 96k output.opus.
4. Use a different bitrate when necessary: 64k is generally adequate for speech, 96k suits mixed speech and music, and 128k provides more headroom for music.

To convert a different audio stream, change -map 0:a:0 to a stream such as -map 0:a:1. If FFmpeg reports that the file is unsupported, first open the recording in a DVR-MS-capable desktop player and export it to WAV or another unprotected intermediate format, then run ffmpeg -i intermediate.wav -c:a libopus -b:a 96k output.opus.

You can also use the free converter on 101convert.com without installing software. Upload the DVR-MS file, choose OPUS as the output format, start the conversion, and download the resulting audio file.

Quality, compatibility, and limitations

OPUS conversion is normally lossy: decoding the source and encoding it again cannot restore information already discarded by the original recording. The output bitrate affects size and quality, but it cannot improve a low-quality source. A DVR-MS file may contain DRM or broadcast copy restrictions; protected recordings may not be readable or exportable by FFmpeg or other converters. The conversion removes video, captions, and recording metadata unless they are separately exported, and some older players recognize the OPUS codec only when the file uses the expected Ogg-based .opus container.