FFmpeg

FFmpeg is required for any audio / video workflow:

• Generate Subtitle — decoding source audio for STT
• Generate Voice — combining timed TTS clips into one file
• Dubbing — STT → TTS → mux back into video
• Live Translation — when system audio capture goes through parec

It's not bundled — install it once on your system.

Install

macOSUbuntu / DebianFedora / RHELArch / ManjaroWindows

brew install ffmpeg

sudo apt update && sudo apt install ffmpeg

sudo dnf install ffmpeg

Or, for a more complete build, enable RPM Fusion first.

sudo pacman -S ffmpeg

Download a static build from https://www.gyan.dev/ffmpeg/builds/ (the "release essentials" build is fine), unzip, then add the bin/ folder to your PATH:

1. Press Win + R, type sysdm.cpl, press Enter
2. Advanced → Environment Variables → System variables → Path → Edit
3. New → paste the absolute path to FFmpeg's bin folder
4. OK all the way out, restart any open terminals

Verify

ffmpeg -version

You should see a version banner with --enable-libx264 --enable-libvpx in the configuration line. If you see "command not found", the installation didn't end up on PATH.

In-app pre-flight check

The Voice / Dubbing pages call shutil.which("ffmpeg") before starting work. If FFmpeg isn't found you'll see a friendly error dialog with a link back here, not a half-run task.

Common error

Error	Meaning
FFMPEG_NOT_FOUND	ffmpeg isn't on PATH at the time the page tried to run it. Install it (above) and restart the app.

In the MCP server (ait-mcp), the same error is re-wrapped into a human-readable message:

"FFmpeg is required to decode this audio/video file but is not installed or not on PATH. Install FFmpeg and try again."