If Auris is useful to you, consider supporting development:
Auris is a desktop audio library scanner for Linux, built for anyone who cares about the quality of their music collection.
It scans your music folders and gives you a deep technical analysis of every file — revealing clipping issues, dynamic range, spectral content, inter-sample peaks, and whether your files carry the frequency content you'd expect from their format.
- Spectral content classification — Full Spectrum / Reduced Spectrum / Limited Spectrum, based on measured frequency content rather than format claims
- Spectral gap measurement — the actual measured dB difference between high-frequency and full-spectrum content, so you can evaluate results yourself
- True peak detection — inter-sample peak measurement via ebur128 oversampling, catching distortion that standard peak measurement misses
- Clipping risk detection — identifies tracks with dangerously loud peaks, using true peak as primary signal
- Dynamic range measurement — reveals over-compressed or heavily limited tracks
- Sample rate & bit depth reporting — full technical breakdown per file
- Compare Files — compare 2–5 audio files side by side with a quality recommendation and clear reasoning
- Multi-threaded scanning — fast parallel analysis of large libraries
- Progress bar with stop button — cancel scans at any time
- Filter & search — filter by spectrum classification, search by filename or metadata
- Export CSV — save results for further analysis
- Dark & light mode — automatically follows your system theme
- Open / Reveal in Folder — quickly act on flagged files
- Built-in help — plain language explanations of every metric
Auris uses FFmpeg to perform analysis of each audio file across three passes:
- Spectral pass — measures energy in frequency bands above 16kHz and 20kHz relative to the full signal, identifying how much high-frequency content is present
- Dynamic range pass — measures peak and RMS levels via direct
astatsto calculate dynamic range reliably across all formats including FLAC - True peak pass — measures inter-sample peaks via
ebur128oversampling, detecting distortion that standard peak measurement misses
Sample rate and bit depth are extracted separately via FFprobe.
Results are displayed in an interactive table with color-coded risk levels and exportable as CSV.
| Column | What it means |
|---|---|
max_volume |
Loudest sample peak in dBFS. Values close to 0.0 dB indicate potential clipping |
mean_volume |
Average loudness. Helps identify heavy compression |
risk |
Clipping risk: High / Moderate / Low. Uses true peak as primary signal when available |
cutoff_freq |
Frequency threshold used for spectral classification (Hz) |
spectral_gap_db |
Measured energy gap (dB) between >20kHz filtered signal and full signal. Larger = less high-frequency content present |
quality |
Spectral content classification — see below |
dynamic_range |
Peak minus RMS level (dB). Higher = more dynamic and natural sounding. Below 8 dB may indicate heavy compression |
true_peak |
Inter-sample peak (dBFS) via oversampling. Values above 0 indicate inter-sample clipping |
sample_rate |
Audio samples per second. 44100 = CD quality. 96000+ = hi-res |
bit_depth |
Bits per sample. 16-bit = CD quality. 24-bit = studio quality |
| Label | What it means |
|---|---|
| Full Spectrum | High-frequency energy detected above 20kHz. Consistent with genuine lossless audio |
| Reduced Spectrum | Frequency content limited above 16kHz. May indicate a high-bitrate lossy source, or a 24-bit file with naturally limited high-frequency content |
| Limited Spectrum | Frequency content limited above 15kHz. Consistent with MP3 or other lossy encoding |
Important: These labels describe measured frequency content, not a claim about how a file was encoded. Vocal and acoustic recordings naturally have limited high-frequency content regardless of format — a genuine lossless FLAC of a vocal performance may show a large spectral gap. 24-bit files are treated as minimum Reduced Spectrum since lossy encoders do not work in 24-bit. Use results as a guide alongside knowledge of your files' original source.
The Compare Files feature lets you select 2–5 audio files and compare their quality characteristics side by side. Auris recommends which version to keep based on:
- Spectral quality label (Full > Reduced > Limited)
- Dynamic range (higher = more natural)
- Sample rate, then bit depth as tiebreakers
- Clipping risk flagged as a warning
Click Compare Files in the toolbar to open the comparison dialog.
- Linux
- FFmpeg (with ebur128 support — included in standard builds)
- libfuse2 (only needed for AppImage)
- libxcb-cursor0 (only needed for AppImage)
- Python 3.12+ (only needed if running from source)
- Download
Auris-x86_64.AppImagefrom the latest release - Make it executable and run:
chmod +x Auris-x86_64.AppImage
./Auris-x86_64.AppImageInstall dependencies if needed (Ubuntu / Debian / Pop!_OS):
sudo apt install ffmpeg libfuse2 libxcb-cursor0git clone https://github.com/noisetta/auris.git
cd auris
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python app.py- WMA support —
.wmafiles now supported in both the scanner and Compare Files dialog - Bug fixes — duplicate widgets in action row, double error dialog on scan failure, help dialog referencing old quality label, app icon not loading inside AppImage
- Version label — current version now visible in the UI
- Typo fix — corrected "EMMS" label in Compare Files dialog
- Compare Files — new feature to compare 2–5 audio files side by side with quality recommendation
- Spectral classification renamed — labels now describe measured frequency content (Full Spectrum / Reduced Spectrum / Limited Spectrum) rather than making provenance claims (Lossless / Likely Lossy / Lossy)
- Spectral Gap column — shows actual measured dB gap so users can evaluate results directly
- True Peak column — inter-sample peak measurement via ebur128 oversampling
- Clipping risk improved — now uses true peak as primary signal, more accurate than sample-peak alone
- Dynamic range fixed for FLAC — uses a separate analysis pass to avoid a known ffmpeg asplit/-inf bug affecting some FLAC files
- 24-bit refinement — 24-bit files with large spectral gaps are classified as Reduced Spectrum minimum, reflecting that lossy encoders do not work in 24-bit
- Help text and tooltips updated — more accurate explanations of what each metric measures and its limitations
- Updated quality labels to Lossless / Likely Lossy / Lossy for clarity
- Added disclaimer in help dialog about spectral analysis limitations
- Added support for .m4a, .aac, .ogg, and .opus audio formats
- Column header display fix
- Initial release
Active development. Planned for upcoming releases:
- Spectrogram export — generate and export spectrograms for scanned files, useful for sharing quality proof with others
- Network transfer monitoring — real-time analysis of incoming audio transfers, designed for Soulseek/Nicotine+ users
- Watched folder daemon — automatic scan of new files as they arrive in a download folder
- AUR package — native installation for Arch-based distributions
Contributions are welcome. Feel free to open issues or pull requests on GitHub.
MIT License — free to use, modify, and distribute.
