Convert HEVC to VOC — Free Online Tool
Extract and convert the audio track from an HEVC/H.265 video file into a VOC file using 8-bit unsigned PCM audio — the retro format developed by Creative Labs for DOS-era Sound Blaster cards. This tool strips the video entirely and resamples the audio into a format compatible with classic DOS games, multimedia applications, and vintage sound hardware.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your HEVC file here
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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
HEVC (.hevc) files contain a raw H.265 video bitstream, which may carry an embedded audio track. During this conversion, FFmpeg discards the entire video stream and decodes the source audio, then re-encodes it as 8-bit unsigned PCM (pcm_u8) wrapped in the VOC container format. The VOC format supports only raw PCM audio — no compression, no metadata, no multiple tracks — so the audio is fully decoded and rewritten from scratch. If the source audio was compressed (e.g., AAC or AC-3), it is fully decoded and then quantized down to 8-bit unsigned PCM, which is a significant reduction in bit depth. The sample rate is preserved unless explicitly overridden, but 8-bit PCM at any rate is a lossy step-down in fidelity compared to modern compressed codecs.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg program — in this browser tool, it runs as a WebAssembly binary (FFmpeg.wasm) entirely within your browser, with no file upload to any server. |
-i input.hevc
|
Specifies the input file — a raw HEVC/H.265 bitstream or HEVC-extension video file. FFmpeg will probe this file to detect any available audio streams alongside the H.265 video data. |
-c:a pcm_u8
|
Sets the audio codec to 8-bit unsigned PCM, which is the native encoding used by the VOC format for Sound Blaster 1.0/2.0 compatibility. The source audio (whatever codec it uses in the HEVC file) is fully decoded and re-encoded into this raw, uncompressed 8-bit format. |
output.voc
|
Specifies the output filename with the .voc extension, which tells FFmpeg to wrap the encoded pcm_u8 audio in a VOC container — the Creative Labs Sound Blaster audio format used in DOS games and early multimedia software. No video data is written to this file. |
Common Use Cases
- Extracting dialogue or sound effects from HEVC-encoded video for use in a retro DOS game or demoscene project that requires VOC audio assets
- Converting a narration or voiceover recorded in an HEVC video file into a VOC file to play back through a Sound Blaster card emulator like DOSBox
- Generating VOC audio assets for a retro-themed game engine or tool that specifically requires Sound Blaster-compatible file formats
- Archiving audio from HEVC video captures of vintage computing sessions into the era-appropriate VOC format for historical preservation projects
- Stripping and converting audio from HEVC content for use in DOS-era multimedia authoring tools that only accept VOC input files
Frequently Asked Questions
Yes — this conversion involves a significant reduction in audio fidelity. The VOC format with pcm_u8 encoding uses only 8 bits per sample, compared to the 16-bit or 24-bit audio typically found in modern HEVC video files. This results in a dynamic range of roughly 48 dB, which introduces audible quantization noise, especially during quiet passages. If your use case demands higher fidelity, you can use the pcm_s16le codec option instead, which provides 16-bit signed PCM and much better dynamic range.
The video stream is completely dropped. FFmpeg maps only the audio stream to the VOC output because the VOC format is audio-only and has no concept of video data. The H.265-encoded video frames are never decoded — they are simply ignored during the conversion process, making the operation faster than a full video transcode.
No. The VOC format does not support metadata of any kind — it is a bare-bones container designed for raw PCM audio playback on Sound Blaster hardware. Any title, artist, language, or chapter information embedded in the HEVC source file will be silently discarded during conversion.
Replace '-c:a pcm_u8' with '-c:a pcm_s16le' in the command to use 16-bit signed little-endian PCM instead. The full command would be: ffmpeg -i input.hevc -c:a pcm_s16le output.voc. The pcm_s16le codec is also supported by the VOC format and provides substantially better audio quality, with a dynamic range closer to CD audio. This is recommended for any audio that contains music or wide dynamic range content.
Yes, on the command line you can use a shell loop to process multiple files. On Linux or macOS, run: for f in *.hevc; do ffmpeg -i "$f" -c:a pcm_u8 "${f%.hevc}.voc"; done. On Windows Command Prompt, use: for %f in (*.hevc) do ffmpeg -i "%f" -c:a pcm_u8 "%~nf.voc". This browser-based tool processes one file at a time, but the displayed FFmpeg command is designed to be run locally for bulk operations or files over 1GB.
A raw .hevc file is technically a pure video elementary stream and typically does not contain audio. However, some tools mislabel or mux files with the .hevc extension even when they contain both audio and video streams. If your file truly has no audio track, FFmpeg will error with 'no audio stream found' and produce no output. In that case, you would need to source the audio separately or use a container format like MKV or MP4 that properly encapsulates both streams.
Technical Notes
The VOC format is a legacy container from the early 1990s designed for Creative Labs Sound Blaster cards and is supported natively by DOS, DOSBox, and various retro game engines. It supports only mono or stereo raw PCM audio — no compression, no chapter markers, no subtitle streams, and no secondary audio tracks. When converting from HEVC, only the first audio stream is mapped by default; any additional audio tracks are silently ignored. The default codec used here is pcm_u8, which encodes samples as unsigned 8-bit integers (values 0–255, with silence at 128). This format was standard for Sound Blaster 1.0 and 2.0 compatibility. The alternative pcm_s16le codec (16-bit signed little-endian) is supported for Sound Blaster 16 compatibility and offers far better dynamic range. Note that the sample rate of the source audio is passed through unchanged — VOC files can technically support various sample rates, but DOS-era hardware typically expected rates like 8000, 11025, 22050, or 44100 Hz. If your target playback environment expects a specific rate, add '-ar 22050' (or your desired rate) to the FFmpeg command. File sizes will be large relative to the audio duration since PCM audio is uncompressed: 8-bit mono at 22050 Hz produces approximately 1.3 MB per minute.