music-seperator-demucs

# Demucs Use `demucs` to split music into stems (default: `vocals`, `drums`, `bass`, `other`). Quick start - Help: `demucs --help` - Basic split: `demucs "input.mp3"` - Output dir: `demucs "input.mp3" -o "D:\\output"` - Vocals only pair: `demucs "input.mp3" --two-stems vocals` Prerequisites - Demucs available: `demucs --help` or absolute path like `D:\demucs-agent-tool\venv\Scripts\demucs.exe --help`. - FFmpeg available: `ffmpeg -version` must succeed. - Note: `ffmpeg-python` is only a Python wrapper and does not install `ffmpeg.exe`. Common options - Model: `-n htdemucs` (default) or other installed model names. - Device: `-d cuda` or `-d cpu`. - Chunking: `--segment 8 --overlap 0.25` to reduce VRAM/RAM pressure. - No chunking: `--no-split` for short audio with enough memory. - Equivariant shifts: `--shifts 1..10` (higher quality, slower). - Parallel jobs: `-j 2` (or more on strong CPUs). Output format - Default output is WAV. - FLAC: `demucs "input.mp3" --flac` - MP3: `demucs "input.mp3" --mp3 --mp3-bitrate 320 --mp3-preset 2` - Safer clipping behavior: `--clip-mode rescale` (default) or `--clip-mode clamp`. Naming and folder layout - Default output path pattern: `separated/<model>/<track>/<stem>.<ext>`. - Customize names: `--filename "{track}/{stem}.{ext}"`. - Variables supported: `{track}`, `{trackext}`, `{stem}`, `{ext}`. Batch usage - Multiple files in one call: `demucs "a.mp3" "b.wav" "c.flac" -o "D:\\separated"`. - Prefer absolute paths for automation scripts and scheduled jobs. Windows notes - In venv, executable is usually `venv\\Scripts\\demucs.exe`. - Use quoted paths when spaces exist: `demucs "D:\\My Music\\song.mp3"`. - For external programs, prefer absolute executable path instead of shell activation. - If non-ASCII paths cause tool/runtime issues, copy input to a temporary ASCII path and run Demucs there. Troubleshooting - `demucs` not found: run `python -m demucs --help` or call `venv\\Scripts\\demucs.exe` directly. - `FFmpeg is not installed` / `ffprobe not found`: install FFmpeg and add it to PATH, then verify with `ffmpeg -version`. - Out of memory: lower `--segment` (for example `6` or `4`), set `-d cpu`, or process fewer tracks at once. - Slow speed on CPU: reduce `--shifts`, keep chunking enabled, and tune `-j`. - Install/network failures: use a stable mirror and longer timeout when running pip.