MyMediaTools

Convert MOV to VOC — Free Online Tool

Convert MOV files to VOC audio format, extracting audio from Apple's QuickTime container and encoding it as raw PCM for classic Sound Blaster compatibility. This tool strips video and remuxes the audio stream as unsigned 8-bit PCM (pcm_u8), the native format of Creative Labs' VOC files used in DOS-era games and applications.

FFmpeg Command

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Estimated output:

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How It Works

During this conversion, FFmpeg discards all video, subtitle, chapter, and additional audio track data from the MOV container — none of which VOC supports. The primary audio stream is then decoded from whatever codec it uses inside the MOV file (typically AAC or PCM) and re-encoded as unsigned 8-bit PCM (pcm_u8), the default and most compatible codec for VOC files. The VOC format was designed by Creative Labs specifically for the Sound Blaster card and stores raw PCM audio with a simple header describing sample rate and bit depth. Because VOC is a lossless, uncompressed format, the output file size is determined purely by the audio duration and sample rate rather than any bitrate setting.

What Each Flag Does

Flag What it does
ffmpeg Invokes the FFmpeg command-line tool, which is the engine running inside your browser via WebAssembly (FFmpeg.wasm) to perform this conversion entirely on your device.
-i input.mov Specifies the input file as a MOV (QuickTime) container, which may contain video, audio, subtitles, chapters, and multiple audio tracks — all of which FFmpeg will parse before determining what to pass to the output.
-c:a pcm_u8 Sets the audio codec to pcm_u8 (unsigned 8-bit PCM), the native and most broadly compatible encoding for VOC files, matching the format originally used by Creative Labs Sound Blaster hardware in DOS-era computing.
output.voc Defines the output filename with the .voc extension, which tells FFmpeg to write a Creative Labs VOC container. Because VOC supports only audio, FFmpeg automatically omits the video stream from the MOV source without requiring an explicit -vn flag.

Common Use Cases

  • Preparing audio samples for use in a retro DOS game mod or Sound Blaster-compatible application that requires native VOC files
  • Archiving or restoring original game audio assets recorded in MOV format back to the VOC format used by classic game engines like iD Tech or BUILD
  • Extracting a voice-over or sound effect recorded in QuickTime on macOS for use in a legacy multimedia authoring tool that only accepts VOC input
  • Converting modern field recordings or Foley sound captured in MOV to VOC for use with DOSBox or other DOS emulators that mount Sound Blaster audio
  • Supplying audio replacements for retro game patches or fan-made total conversions where the engine hardcodes VOC file loading
  • Extracting a clean audio track from a professional MOV recording to produce a raw PCM reference file via the well-documented VOC container format

Frequently Asked Questions

It depends on the audio codec inside your MOV file. If the MOV contains AAC or MP3 audio, that lossy audio must first be decoded and then re-encoded as pcm_u8, introducing a generation of decode loss. Additionally, pcm_u8 stores only 8 bits of amplitude resolution per sample, which is significantly lower than the 16-bit or 24-bit audio common in professional MOV files — so you will notice a reduction in dynamic range and a slight increase in noise floor compared to the source. If preserving fidelity is critical, consider using the pcm_s16le codec option instead, which doubles the bit depth to 16 bits and more closely matches modern recording quality.
All of them are silently dropped. VOC is a pure audio-only format with no container support for video streams, subtitle tracks, chapter markers, or multiple audio tracks — all features that MOV natively supports. FFmpeg automatically handles this by selecting only the first audio stream from the MOV file and ignoring everything else. If your MOV file contains multiple audio tracks, only the default (first) track will appear in the output VOC file.
The original VOC format specification supports sample rates up to 44,100 Hz for stereo audio and higher rates for mono, tied to limitations of the original Sound Blaster hardware. FFmpeg will attempt to preserve the sample rate from your MOV source, but if your MOV audio was recorded at 48 kHz or 96 kHz (common in professional workflows), the output may be resampled depending on VOC compatibility requirements. For maximum compatibility with DOS applications and emulators like DOSBox, a sample rate of 22,050 Hz or 44,100 Hz mono or stereo is recommended.
Replace pcm_u8 with pcm_s16le in the command, making it: ffmpeg -i input.mov -c:a pcm_s16le output.voc. This encodes the audio as signed 16-bit little-endian PCM, which is the other codec VOC supports and doubles the dynamic range compared to the default 8-bit output. Note that 16-bit VOC files are less universally supported by the oldest Sound Blaster hardware and some legacy applications, but work correctly in DOSBox and most modern retro gaming tools.
Yes — on the command line you can use a shell loop to process many files at once. On Linux or macOS, run: for f in *.mov; do ffmpeg -i "$f" -c:a pcm_u8 "${f%.mov}.voc"; done. On Windows Command Prompt, use: for %f in (*.mov) do ffmpeg -i "%f" -c:a pcm_u8 "%~nf.voc". The browser-based tool on this page processes one file at a time and is best suited for files under 1 GB; the command-line approach is more practical for batch workflows or large archives.
MOV files typically use compressed audio codecs like AAC, which achieve high quality at low bitrates through psychoacoustic compression. VOC stores raw uncompressed PCM, so even 8-bit pcm_u8 at 44,100 Hz stereo produces about 88 KB per second of audio — with no bitrate ceiling. A short MOV with highly compressed AAC audio could actually expand significantly when written to VOC. Conversely, a long MOV with a high-bitrate video stream will appear much smaller as a VOC because all video data is discarded and only the audio remains.

Technical Notes

VOC is one of the oldest surviving digital audio container formats still in active use, maintained almost exclusively by the retro gaming and emulation communities. The format stores audio in a block-based structure with a 26-byte file header followed by typed data blocks, but from a practical standpoint FFmpeg treats it as a straightforward raw PCM container. The default codec for this conversion is pcm_u8 (unsigned 8-bit PCM), which uses values from 0–255 to represent amplitude with 128 as the silence midpoint — a quirk inherited from early Sound Blaster hardware design. The alternative pcm_s16le codec uses signed 16-bit values (-32768 to 32767) and is more compatible with modern expectations of audio quality. Crucially, VOC has no support for metadata of any kind — no title, artist, album, or encoder tags — so all QuickTime metadata atoms embedded in the MOV file are permanently lost in the output. The format also cannot store multichannel audio beyond stereo, has no concept of variable bitrate, and provides no mechanism for compression. Files are always lossless relative to the PCM representation, but the 8-bit default imposes a hard quality ceiling well below any professional or consumer MOV source. For DOS emulation use cases, ensure the sample rate and bit depth match what the target application or game engine expects, as VOC files are often loaded with hardcoded format assumptions.

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