Convert M2TS to VOC — Free Online Tool
Convert M2TS Blu-ray video files to VOC audio format, extracting the audio stream and encoding it as raw PCM unsigned 8-bit audio compatible with Creative Labs Sound Blaster and DOS-era applications. This tool strips the video and container metadata entirely, outputting a bare-bones legacy audio file from high-definition Blu-ray source material.
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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
During this conversion, FFmpeg demuxes the M2TS transport stream container — which typically carries H.264 or H.265 video alongside multichannel audio codecs like AC-3, DTS, or AAC — and discards all video streams entirely. The first audio track is decoded from its source codec and then re-encoded as PCM unsigned 8-bit (pcm_u8) audio, which is the native format of Creative Labs VOC files. This is a lossy downgrade in bit depth terms: Blu-ray audio is typically 16-bit or higher, so reducing to 8-bit unsigned PCM will produce audible quality degradation, particularly in dynamic range and noise floor. The VOC container itself is extremely minimal, with no support for metadata, chapters, subtitles, or multiple audio tracks — all of which the M2TS source may contain.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool. In the browser-based version of this tool, this runs via FFmpeg.wasm compiled to WebAssembly, executing entirely within your browser without sending any file data to a server. |
-i input.m2ts
|
Specifies the input file as an M2TS container — a BDAV MPEG-2 Transport Stream as used on Blu-ray discs and AVCHD camcorders. FFmpeg will demux all streams (video, audio, subtitles) from this container, making them available for selective output. |
-c:a pcm_u8
|
Sets the audio output codec to PCM unsigned 8-bit, which is the native and default audio encoding for the VOC format. This re-encodes whatever audio codec is present in the M2TS source (AC-3, DTS, AAC, etc.) into raw 8-bit uncompressed PCM, which is the only audio format that DOS-era VOC-compatible software universally understands. |
output.voc
|
Specifies the output filename with the .voc extension, which causes FFmpeg to mux the encoded PCM audio into a Creative Labs VOC container. The VOC container adds a minimal file header identifying the audio format parameters before the raw PCM sample data. |
Common Use Cases
- Extracting a specific sound effect or short audio clip from a Blu-ray rip for use in a DOS game mod or retro game project that requires VOC-format audio assets.
- Creating period-accurate audio samples in VOC format from modern high-definition source material for use in DOSBox-based game development or emulation projects.
- Archiving a specific audio segment from an AVCHD camcorder recording in a legacy format for playback on vintage Sound Blaster hardware or software.
- Preparing audio assets from Blu-ray disc content for integration into older multimedia authoring tools that only accept VOC files as input.
- Downsampling and converting high-definition broadcast or Blu-ray audio to the minimal bit depth required by retro demo scene productions targeting DOS-era platforms.
Frequently Asked Questions
Yes, significantly. M2TS files from Blu-ray discs typically carry audio at 16-bit, 24-bit, or even lossless formats like DTS-HD MA or Dolby TrueHD, often at 48kHz or 96kHz. VOC with pcm_u8 encoding is limited to 8-bit unsigned PCM, which dramatically reduces dynamic range to roughly 48dB compared to the 96dB+ of 16-bit audio. The result will sound noticeably noisier and flatter, which is expected for this legacy format.
By default, FFmpeg selects the first audio stream found in the M2TS transport stream container. M2TS files — especially from Blu-ray discs — often contain multiple audio tracks such as a primary lossless track and a secondary commentary or dubbed language track. If you need a specific track, you would need to modify the FFmpeg command to add a stream specifier like '-map 0:a:1' to select the second audio stream.
All video streams, subtitle streams, and chapter markers are completely discarded during this conversion. VOC is a pure audio-only container with no ability to carry video data, subtitle tracks, or structural metadata like chapter points. Only audio data survives the conversion, and even then only a single mono or stereo track can be represented in the output VOC file.
Yes. The VOC format supports both pcm_u8 (8-bit unsigned) and pcm_s16le (16-bit signed little-endian) PCM encoding. To use the higher-quality 16-bit codec, change the command to 'ffmpeg -i input.m2ts -c:a pcm_s16le output.voc'. This will preserve significantly more dynamic range from the original M2TS audio and is recommended if your target application supports 16-bit VOC files, which most Sound Blaster-compatible software does.
You can batch process files using a shell loop. On Linux or macOS, run: 'for f in *.m2ts; do ffmpeg -i "$f" -c:a pcm_u8 "${f%.m2ts}.voc"; done'. On Windows Command Prompt, use: 'for %f in (*.m2ts) do ffmpeg -i "%f" -c:a pcm_u8 "%~nf.voc"'. Note that the browser-based tool processes one file at a time, so the FFmpeg command is particularly useful for batch workflows on your local machine.
M2TS files are large because they contain high-definition video streams (often encoded at multi-megabit H.264 or H.265 bitrates), multiple audio tracks, and sometimes subtitle data — all wrapped in a broadcast-oriented MPEG-2 Transport Stream container. The VOC output contains only a single audio track encoded as raw 8-bit uncompressed PCM with no container overhead beyond a minimal header, and with no video whatsoever. The size reduction can be extreme, sometimes thousands-to-one, depending on the length and video bitrate of the source M2TS file.
Technical Notes
The VOC format was designed by Creative Labs in the early 1990s for Sound Blaster cards and has virtually no modern adoption outside retro computing and emulation contexts. Its structure is a simple chunked container carrying raw PCM data preceded by a small header identifying the sample rate and bit depth. When converting from M2TS, FFmpeg must fully decode the source audio codec — which could be AC-3, E-AC-3, DTS, DTS-HD, AAC, or LPCM depending on the Blu-ray disc — before re-encoding to pcm_u8 or pcm_s16le. There is no passthrough or remux path possible here since no modern Blu-ray audio codec is native to VOC. The sample rate of the output will be inherited from the source unless explicitly resampled with '-ar'; note that very high sample rates from Blu-ray sources (96kHz, 192kHz) may produce VOC files that are incompatible with some legacy playback software that expects 8kHz, 11.025kHz, 22.05kHz, or 44.1kHz. VOC files do not support metadata fields such as title, artist, or album tags, so all M2TS container metadata is silently dropped. Multichannel audio (5.1 or 7.1 surround) will be downmixed to stereo or mono by FFmpeg's default behavior during the codec conversion.