Convert DVR to WMA — Free Online Tool
Convert DVR recordings to WMA audio by extracting and transcoding the AAC audio track to Windows Media Audio (wmav2) format. This is ideal for pulling audio from surveillance or broadcast capture footage into a lightweight, widely-supported Windows-native format.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
DVR files typically store video (H.264/libx264) alongside AAC-encoded audio in a proprietary container used by digital video recorders. Since WMA is a pure audio format with no video container support, the video stream is discarded entirely during this conversion — only the audio track is processed. The AAC audio is decoded and then re-encoded using the wmav2 codec (Windows Media Audio v2) at 128kbps by default. This is a full transcode, not a remux, meaning the audio signal is decompressed from AAC and recompressed into WMA, which introduces a generation of lossy compression. The resulting .wma file is a self-contained Windows Media Audio file compatible with Windows Media Player, legacy Windows software, and many media players that support the ASF/WMA container.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, the open-source multimedia processing engine that powers this conversion both in the browser (via FFmpeg.wasm) and locally on your desktop. |
-i input.dvr
|
Specifies the input DVR file. FFmpeg reads the proprietary DVR container and demuxes its streams — in this case identifying the audio track (typically AAC) for extraction, while the video stream is implicitly ignored since WMA cannot contain video. |
-c:a wmav2
|
Sets the audio codec to wmav2 (Windows Media Audio v2), Microsoft's standard lossy audio codec. This re-encodes the source AAC audio into WMA format, which is natively supported by Windows Media Player and the broader Windows ecosystem. |
-b:a 128k
|
Sets the audio output bitrate to 128 kilobits per second. This is the default balance point for WMA — adequate for speech and general audio from DVR recordings, producing files of roughly 1MB per minute. Increase to 192k or 256k if the source audio quality warrants it. |
output.wma
|
Defines the output filename and triggers FFmpeg to write the result as a WMA file wrapped in an ASF container. The .wma extension is recognized universally by Windows applications and media players that support Windows Media Audio. |
Common Use Cases
- Extracting spoken audio from a DVR-recorded broadcast or surveillance footage to archive as a compact WMA file for use on Windows-based systems
- Converting DVR security camera recordings to WMA so the audio (e.g., ambient sound or intercom audio) can be reviewed or logged separately from the video
- Preparing audio from a DVR-captured TV broadcast for playback on older Windows Media Player-based devices or car stereos that support WMA but not AAC
- Stripping and converting the audio track from DVR footage for use in Windows-native media workflows where WMA is the required delivery format
- Reducing file size by discarding the video stream from a large DVR recording and retaining only the WMA audio for voice or audio-only archiving purposes
- Feeding DVR-sourced audio into legacy Windows-based media management software or digital signage systems that require WMA input
Frequently Asked Questions
No. WMA is a strictly audio-only format and cannot contain any video data. During this conversion, the H.264 or MJPEG video stream from your DVR file is completely discarded, and only the audio track is extracted and re-encoded. If you need to keep the video, you should convert to a format like MP4 or MKV instead.
Yes, there is a quality penalty. Your DVR file's audio is already lossy AAC, and transcoding it to wmav2 means decoding it fully and recompressing it with a second lossy codec — a process sometimes called 'double lossy' encoding. At 128kbps, wmav2 produces acceptable results for speech and ambient audio, but for music or high-fidelity content originally recorded at high AAC bitrates, audible artifacts may be more noticeable. Raising the output bitrate to 192k or 256k can reduce but not eliminate this degradation.
Modify the -b:a flag in the command. For example, replace '128k' with '192k' for higher quality: ffmpeg -i input.dvr -c:a wmav2 -b:a 192k output.wma. For smaller file sizes at reduced quality, use '96k' or '64k'. WMA supports bitrates from 64k up to 320k, so you can tune this to match your storage or quality requirements.
Yes, by replacing '-c:a wmav2' with '-c:a wmav1' in the command. WMA v1 (wmav1) is an older codec with slightly lower compression efficiency and is primarily useful for compatibility with very old Windows Media Player versions or legacy hardware. For virtually all modern use cases, wmav2 is preferable as it produces better audio quality at the same bitrate.
DVR files store proprietary metadata that FFmpeg cannot reliably read or map to standard tags. The WMA format does support metadata tags such as title, artist, and album within its ASF container, but DVR-specific fields like camera ID, recording timestamp, or channel name will not automatically transfer. You would need to manually set WMA tags using FFmpeg's -metadata flag if needed.
Yes. On Linux or macOS, you can use a shell loop: for f in *.dvr; do ffmpeg -i "$f" -c:a wmav2 -b:a 128k "${f%.dvr}.wma"; done. On Windows Command Prompt, use: for %f in (*.dvr) do ffmpeg -i "%f" -c:a wmav2 -b:a 128k "%~nf.wma". This processes each DVR file in the current directory and outputs a corresponding WMA file with the same base filename.
Technical Notes
DVR is a proprietary container format with no single universal specification — different manufacturers (surveillance NVRs, set-top boxes, broadcast recorders) implement it differently, which means FFmpeg's ability to demux a given DVR file depends on how closely it conforms to recognizable container structures. Audio in DVR files is most commonly AAC at bitrates ranging from 64kbps to 192kbps. WMA uses Microsoft's ASF (Advanced Systems Format) as its container, and the wmav2 codec is the standard choice, offering better compression than wmav1 with broad compatibility across Windows platforms. One important limitation: WMA does not support multiple audio tracks, chapters, or subtitles, none of which are concerns for a DVR-to-WMA extraction since only a single audio stream is being processed. DRM support is a WMA feature but is not applied by FFmpeg during conversion. File sizes will vary significantly based on source audio duration and the chosen output bitrate; at 128kbps, expect approximately 1MB per minute of audio.