DVMS to CAF Converter

Upload DVMS, download CAF — no installs required

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Settings

The codec to encode the audio track. Codec "Without reencoding" copies the audio stream from the input file into output without re-encoding if possible.
Set the number of audio channels. This setting is most useful when downmixing channels (e.g., from 5.1 to stereo).
Set the sample rate of the audio. Music with a full spectrum (20 Hz — 20 kHz) requires values not lower than 44.1 kHz to achieve transparency. More info can be found on the wiki.

dvms

DVMS (Dutch Voice Messaging System) is a telephony-grade audio encoding born from the Netherlands' early push toward digital voicemail infrastructure. Deployed through KPN (formerly PTT Telecom) in the mid-1980s, the format stores mono voice data at a narrow 8 kHz sample rate, prioritizing compact message size over sonic breadth. Audio is compressed with a proprietary variant of logarithmic companding similar to European A-law encoding, squeezing recordings to roughly 8 kbit/s while keeping speech intelligible. Each file carries a small header identifying sample rate, compression type, and message metadata, which made automated routing across early PBX and voicemail systems straightforward. Although DVMS never gained traction outside Dutch telecom circles, it influenced how European carriers designed later voice messaging protocols. Tools like SoX and several legacy telephony libraries still read and write DVMS files, allowing archival playback of decades-old messages. Among its practical advantages: extremely small file sizes (a one-minute message occupies roughly 60 KB), reliable speech clarity despite aggressive compression, and a simple container layout that is easy to parse programmatically.
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caf

CAF (Core Audio Format) is a flexible audio container developed by Apple and introduced with Mac OS X 10.4 Tiger in 2005. Built to overcome limitations of older formats, CAF eliminates the 4 GB file size ceiling that constrains WAV and AIFF, theoretically supporting unlimited length. The container accommodates virtually any codec — AAC, ALAC, MP3, linear PCM, IMA ADPCM, and more — within a unified wrapper. Its chunk-based architecture stores audio alongside rich metadata including channel layouts, marker regions, annotations, and MIDI data. A defining advantage is handling extremely long recordings: broadcasters and field recordists can capture hours of continuous audio without size boundaries. Flexible codec support is another strength, as one container works whether the content is high-resolution 24-bit/192 kHz lossless audio or compressed speech. Apple's Core Audio framework provides native support on macOS and iOS, ensuring low-latency playback in professional applications like Logic Pro and Final Cut Pro. For Apple ecosystem workflows requiring both versatility and scale, CAF is an exceptionally capable choice.
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Confidential Handling

All uploaded files are handled securely — DVMS inputs are removed after processing, and CAF outputs expire within 24 hours.

Format Transition

DVMS recordings become far more usable as CAF. The conversion unlocks supports multiple codecs in one container that DVMS cannot provide.

Bulk Conversion

Handle multiple DVMS to CAF conversions at once. Upload your batch and let the converter process them in parallel.

How to convert DVMS to CAF

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose caf or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your caf file right afterwards

About formats

DVMS (Dutch Voice Messaging System) is a telephony-grade audio encoding born from the Netherlands' early push toward digital voicemail infrastructure. Deployed through KPN (formerly PTT Telecom) in the mid-1980s, the format stores mono voice data at a narrow 8 kHz sample rate, prioritizing compact message size over sonic breadth. Audio is compressed with a proprietary variant of logarithmic companding similar to European A-law encoding, squeezing recordings to roughly 8 kbit/s while keeping speech intelligible. Each file carries a small header identifying sample rate, compression type, and message metadata, which made automated routing across early PBX and voicemail systems straightforward. Although DVMS never gained traction outside Dutch telecom circles, it influenced how European carriers designed later voice messaging protocols. Tools like SoX and several legacy telephony libraries still read and write DVMS files, allowing archival playback of decades-old messages. Among its practical advantages: extremely small file sizes (a one-minute message occupies roughly 60 KB), reliable speech clarity despite aggressive compression, and a simple container layout that is easy to parse programmatically.
Developer: Dutch PTT Telecom
Initial release: 1984
CAF (Core Audio Format) is a flexible audio container developed by Apple and introduced with Mac OS X 10.4 Tiger in 2005. Built to overcome limitations of older formats, CAF eliminates the 4 GB file size ceiling that constrains WAV and AIFF, theoretically supporting unlimited length. The container accommodates virtually any codec — AAC, ALAC, MP3, linear PCM, IMA ADPCM, and more — within a unified wrapper. Its chunk-based architecture stores audio alongside rich metadata including channel layouts, marker regions, annotations, and MIDI data. A defining advantage is handling extremely long recordings: broadcasters and field recordists can capture hours of continuous audio without size boundaries. Flexible codec support is another strength, as one container works whether the content is high-resolution 24-bit/192 kHz lossless audio or compressed speech. Apple's Core Audio framework provides native support on macOS and iOS, ensuring low-latency playback in professional applications like Logic Pro and Final Cut Pro. For Apple ecosystem workflows requiring both versatility and scale, CAF is an exceptionally capable choice.
Developer: Apple Inc.
Initial release: 2005

Frequently Asked Questions

Why should I switch from DVMS to CAF?

DVMS suffers from German telephony format not recognized by standard media players. CAF offers native to Apple pro audio.

Which software opens CAF recordings?

You can open CAF with QuickTime, Logic Pro, GarageBand, and Apple audio tools.

Is there quality loss from DVMS to CAF?

No quality is lost. CAF stores audio without additional compression, so your DVMS recording carries over at full original fidelity.

Is DVMS to CAF conversion available on all platforms?

It works on any platform — desktop or mobile. Just open your browser, upload the DVMS recording, and convert to CAF.

Is my DVMS audio kept private during conversion?

Your uploaded DVMS recordings are deleted immediately after conversion. The resulting CAF outputs are removed within 24 hours.

Do I need to install anything for DVMS to CAF?

No installation required. The converter runs entirely in your web browser — just upload, convert, and download.