Extract Audio from 3GP to DSS — Free Online Tool
Extract audio from 3GP mobile video files and convert it to DSS (Digital Speech Standard) format using the ADPCM IMA OKI codec — ideal for feeding mobile-recorded speech into Olympus, Philips, or Grundig dictation workflows. The conversion strips the video stream entirely and re-encodes the audio to the low-bitrate, speech-optimized DSS container.
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
3GP files typically carry AAC or MP3 audio alongside H.264 video, optimized for 3G mobile transmission. During this conversion, FFmpeg discards the video stream entirely using the -vn flag, then re-encodes the audio track from AAC (or MP3) to ADPCM IMA OKI — the only codec supported by the DSS container. ADPCM IMA OKI is a low-bitrate adaptive delta PCM codec historically used in Olympus digital voice recorders, so the output is mono, speech-optimized, and extremely compact. No video data is preserved, and the output is a pure audio file compatible with professional dictation software.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version of this tool, FFmpeg runs locally via WebAssembly (FFmpeg.wasm) with no server upload required. |
-i input.3gp
|
Specifies the input 3GP file — a mobile multimedia container that typically holds H.264 video alongside AAC or MP3 audio recorded on a 3G mobile device. |
-vn
|
Disables video output entirely, discarding the H.264 (or MJPEG) video stream from the 3GP file. This is required because DSS is a pure audio container and cannot hold any video data. |
-c:a adpcm_ima_oki
|
Encodes the audio using the ADPCM IMA OKI codec — the only codec supported by the DSS container — which produces narrow-band, mono, speech-optimized audio at a fixed low bitrate compatible with Olympus, Philips, and Grundig dictation devices. |
output.dss
|
Writes the result as a DSS file (Digital Speech Standard), a proprietary dictation audio container. FFmpeg selects the DSS muxer based on this file extension, packaging the ADPCM IMA OKI audio stream in the correct format. |
Common Use Cases
- Transferring a voice memo or dictation recorded on an older 3G mobile phone into a DSS-compatible transcription platform like SpeechExec or SpeechLive
- Archiving mobile-recorded spoken notes from a 3GP file into a DSS library managed by Olympus or Philips dictation hardware
- Converting a 3GP interview or field recording captured on a basic mobile device into DSS format for a legal or medical transcription service that only accepts DSS input
- Extracting speech from a 3GP video log and compressing it into DSS for storage on a digital voice recorder with limited internal memory
- Preparing mobile-sourced audio evidence or voice notes in DSS format for import into court transcription or case management systems that mandate DSS
Frequently Asked Questions
Yes, expect a meaningful quality reduction. 3GP files commonly store audio as AAC at 64 kbps or higher, which is a relatively modern and efficient codec. ADPCM IMA OKI, used in DSS, is a much older, lower-fidelity codec designed specifically for intelligible speech — not music or wideband audio. The result will be narrow-band, mono speech audio. For voice recordings and dictation this is typically acceptable, but any music or ambient sound in the 3GP file will sound noticeably degraded.
No, DSS does not support stereo. The ADPCM IMA OKI codec used in DSS files is inherently mono. If your 3GP file contains stereo audio, FFmpeg will automatically downmix it to mono during the conversion. For speech recordings this is generally not a problem, but be aware that any stereo separation in the original file will be lost.
No — the DSS format with the ADPCM IMA OKI codec does not expose adjustable quality or bitrate parameters in FFmpeg. The codec operates at a fixed encoding rate determined by the format specification, which is why there are no -b:a or -q:a flags in the FFmpeg command for this conversion. If you need higher-quality audio output, DSS is not the appropriate target format for that goal.
The -vn flag tells FFmpeg to ignore all video streams in the input file. Since 3GP files contain both video and audio tracks, without -vn FFmpeg would attempt to include the video in the output. Because DSS is a pure audio container with no video support, including -vn prevents errors and ensures only the audio track is processed and written to the output DSS file.
You can use a shell loop to process multiple files. On Linux or macOS, run: for f in *.3gp; do ffmpeg -i "$f" -vn -c:a adpcm_ima_oki "${f%.3gp}.dss"; done. On Windows Command Prompt, use: for %f in (*.3gp) do ffmpeg -i "%f" -vn -c:a adpcm_ima_oki "%~nf.dss". Each 3GP file in the directory will be converted to a corresponding DSS file with the same base filename.
Compatibility depends on the specific software version and DSS variant expected. DSS has two main variants — DSS Classic and DSS Pro (DS2) — and FFmpeg writes the original DSS Classic format using ADPCM IMA OKI. Most Olympus ODMS, Philips SpeechExec, and older Grundig applications support DSS Classic. However, newer platforms may prefer DS2 or WAV input, so verify your target software's accepted formats before batch converting a large archive.
Technical Notes
The DSS container is a proprietary format developed jointly by Olympus, Philips, and Grundig and is not a general-purpose audio format — it exists exclusively in the context of professional digital dictation hardware and software. FFmpeg's DSS muxer supports only the ADPCM IMA OKI codec, which samples at 8000 Hz mono, making it well-suited to telephone-quality speech but unsuitable for any other audio content. The 3GP input side presents no unusual challenges — FFmpeg reads 3GP reliably regardless of whether the audio track is AAC or MP3 — but the re-encoding step from either of those modern codecs to ADPCM IMA OKI is a lossy transcode that cannot be reversed to recover the original audio quality. There is no metadata (title, author, timestamps) carried over from the 3GP container into DSS, as the DSS format has its own proprietary metadata structure that FFmpeg does not populate from generic tags. Files sizes will be very small given the low fixed bitrate of ADPCM IMA OKI, often smaller than the original 3GP file despite the video being removed.