Convert AIFF to VOC — Free Online Tool
Convert AIFF audio files to VOC format, transcoding Apple's uncompressed PCM audio down to 8-bit unsigned PCM (pcm_u8) compatible with Creative Labs' Sound Blaster format. This is a niche but precise conversion for retro gaming, DOS emulation, and legacy multimedia projects that require the VOC container.
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FFmpeg Command
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Estimated output:
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DownloadHow It Works
AIFF stores audio as big-endian PCM, typically at 16-bit or higher bit depth (pcm_s16be, pcm_s24be, or pcm_s32be). VOC, developed by Creative Labs for the Sound Blaster card, supports only 8-bit unsigned PCM (pcm_u8) or 16-bit little-endian PCM (pcm_s16le). This conversion uses FFmpeg to decode the AIFF PCM stream and re-encode it as pcm_u8 — reducing bit depth from 16/24/32-bit signed big-endian to 8-bit unsigned little-endian. This is a lossy transformation in terms of dynamic range: 8-bit PCM has only 256 amplitude levels compared to the 65,536 of 16-bit audio, resulting in audible quantization noise on complex or dynamic material. The sample rate and channel count from the AIFF source are preserved unless you specify otherwise.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool, which handles decoding the AIFF input, converting the PCM stream between formats, and writing the VOC output container. |
-i input.aiff
|
Specifies the input file — an AIFF audio file containing big-endian uncompressed PCM audio (typically pcm_s16be, pcm_s24be, or higher). FFmpeg reads and decodes this stream for reprocessing. |
-c:a pcm_u8
|
Sets the audio codec to 8-bit unsigned PCM (pcm_u8), which is the native and default encoding for VOC files. This reduces the bit depth from AIFF's 16-bit or higher signed big-endian format to 8-bit unsigned, converting amplitude representation and byte order to match the Sound Blaster VOC specification. |
output.voc
|
Specifies the output file with the .voc extension, which tells FFmpeg to write the Creative Labs VOC container format with the pcm_u8 encoded audio stream inside it. |
Common Use Cases
- Preparing custom sound effects for DOS game mods that require Sound Blaster-compatible VOC files for game engines like Build or id Tech 1
- Creating audio assets for DOSBox-based retro gaming projects where VOC is the native sound format expected by the game executable
- Converting professionally recorded AIFF audio (e.g., voice lines or foley) into lo-fi 8-bit VOC clips for authentic chiptune or retro multimedia presentations
- Supplying VOC-formatted audio to legacy hardware synthesizers or vintage sound cards that accept VOC playback directly
- Archiving or porting 1990s-era multimedia CD-ROM content that originally shipped with VOC audio, starting from a clean AIFF source master
- Testing audio rendering pipelines in retro emulators by supplying known-good AIFF sources and verifying their VOC output
Frequently Asked Questions
Yes, significantly. AIFF typically stores audio at 16-bit or higher precision with thousands of distinguishable amplitude levels, while the default VOC output uses 8-bit unsigned PCM (pcm_u8), which has only 256 levels. This reduction in bit depth introduces quantization noise — a kind of graininess or hiss — that becomes especially noticeable in quiet passages or with wide-dynamic-range source material. The VOC format was designed for early 1990s PC sound hardware, so this lo-fi character is expected and historically appropriate for its intended use cases.
Yes. VOC supports 16-bit little-endian PCM (pcm_s16le) in addition to the default 8-bit. To use it, modify the FFmpeg command to: ffmpeg -i input.aiff -c:a pcm_s16le output.voc. This preserves significantly more dynamic range and is closer in fidelity to the original AIFF, though compatibility with very old DOS software or hardware expecting strict 8-bit VOC files may vary.
No. The VOC format has no standardized metadata container — it is essentially a raw PCM audio stream with a minimal Sound Blaster-specific header. Any ID3-style or chunk-based metadata embedded in your AIFF file (title, artist, comments) will be discarded during conversion. If metadata preservation matters, you should keep the original AIFF as your archive master.
VOC files support a limited set of sample rates dictated by the Sound Blaster hardware era, with 8000 Hz and 22050 Hz being historically common. FFmpeg will attempt to write whatever sample rate your AIFF source uses, but playback on authentic DOS software or emulators may expect specific rates. If your AIFF is at 44100 Hz or 48000 Hz, consider adding -ar 22050 to the FFmpeg command to downsample to a rate more compatible with classic VOC players.
On Linux or macOS, you can run: for f in *.aiff; do ffmpeg -i "$f" -c:a pcm_u8 "${f%.aiff}.voc"; done. On Windows Command Prompt, use: for %f in (*.aiff) do ffmpeg -i "%f" -c:a pcm_u8 "%~nf.voc". This applies the same pcm_u8 encoding used by this tool to every AIFF file in the current directory, outputting a matching VOC file for each.
AIFF is an Apple format rooted in Motorola 68000 architecture, which uses big-endian byte ordering — so its PCM codec is pcm_s16be (signed 16-bit big-endian). Creative Labs' Sound Blaster and DOS environment used x86 architecture, which is little-endian, hence VOC's 8-bit unsigned (pcm_u8) or 16-bit little-endian (pcm_s16le) encoding. FFmpeg handles this byte-order and signedness conversion automatically during the transcode step.
Technical Notes
VOC is one of the oldest structured audio file formats still supported by FFmpeg, predating WAV and MP3 by several years. Its header identifies the file as Sound Blaster VOC and encodes audio in discrete data blocks. The format's 8-bit unsigned PCM default (pcm_u8) represents silence as 128 (0x80) rather than 0, which is a quirk of unsigned representation distinct from signed PCM formats. AIFF's pcm_s16be codec stores silence as 0 and uses two's complement signed integers — FFmpeg must convert both the signedness and the byte order during this transcode. Because VOC has no support for metadata, chapters, or multiple audio tracks — none of which AIFF commonly uses anyway — the only real data loss is the bit-depth reduction. File sizes for the resulting VOC will typically be smaller than the source AIFF (roughly half for 8-bit vs 16-bit source) due to reduced bytes per sample, though high sample rates can still produce large files. For authentic DOS game compatibility, mono audio at 22050 Hz or 8000 Hz using pcm_u8 is the safest target configuration.