audio-normalizer
Use when asked to normalize audio volume, match loudness, or apply peak/RMS normalization to audio files.
When & Why to Use This Skill
The Audio Normalizer skill is a professional-grade utility designed to standardize audio volume levels across various formats. It addresses the challenge of inconsistent loudness in media production by offering Peak normalization, RMS normalization, and LUFS matching (EBU R128/ITU BS.1770). This tool ensures that podcasts, music tracks, and video audio meet industry standards, providing a uniform listening experience while preventing digital clipping and preserving audio fidelity.
Use Cases
- Podcast Production: Automatically normalize multiple voice tracks to a consistent RMS level, ensuring clear and balanced dialogue throughout an episode.
- Music Playlist Leveling: Apply peak normalization to a collection of songs to ensure uniform maximum volume across a playlist without distortion.
- Broadcast & Streaming Compliance: Match audio files to specific LUFS targets (e.g., -16 LUFS for streaming or -23 LUFS for broadcast) to meet platform requirements.
- Batch Media Processing: Efficiently process entire directories of audio files to apply uniform gain adjustments, saving significant time in post-production workflows.
- Video Sound Preparation: Standardize audio levels from diverse recording sources before importing them into video editing software for final mixing.
| name | audio-normalizer |
|---|---|
| description | Use when asked to normalize audio volume, match loudness, or apply peak/RMS normalization to audio files. |
Audio Normalizer
Normalize audio volume levels using peak or RMS normalization to ensure consistent loudness across files.
Purpose
Volume normalization for:
- Podcast episode consistency
- Music playlist leveling
- Speech recording standardization
- Broadcast loudness compliance
Features
- Peak Normalization: Normalize to maximum peak level (dBFS)
- RMS Normalization: Normalize to average loudness level
- Loudness Matching: Match LUFS target for broadcast compliance
- Batch Processing: Normalize multiple files to same level
- Format Preservation: Maintain original audio format
- Headroom Control: Prevent clipping with configurable headroom
Quick Start
from audio_normalizer import AudioNormalizer
# Peak normalization to -1 dBFS
normalizer = AudioNormalizer()
normalizer.load('input.mp3')
normalizer.normalize_peak(target_dbfs=-1.0)
normalizer.save('normalized.mp3')
# RMS normalization for consistent average loudness
normalizer.normalize_rms(target_dbfs=-20.0)
normalizer.save('normalized_rms.mp3')
# Batch normalize all files to same level
normalizer.batch_normalize(
input_files=['audio1.mp3', 'audio2.mp3'],
output_dir='normalized/',
method='rms',
target_dbfs=-20.0
)
CLI Usage
# Peak normalization
python audio_normalizer.py input.mp3 --output normalized.mp3 --method peak --target -1.0
# RMS normalization
python audio_normalizer.py input.mp3 --output normalized.mp3 --method rms --target -20.0
# Batch normalize directory
python audio_normalizer.py *.mp3 --output-dir normalized/ --method rms --target -20.0
# Show current levels without normalizing
python audio_normalizer.py input.mp3 --analyze-only
API Reference
AudioNormalizer
class AudioNormalizer:
def load(self, filepath: str) -> 'AudioNormalizer'
def normalize_peak(self, target_dbfs: float = -1.0, headroom: float = 0.1) -> 'AudioNormalizer'
def normalize_rms(self, target_dbfs: float = -20.0) -> 'AudioNormalizer'
def analyze_levels(self) -> Dict[str, float]
def save(self, output: str, format: str = None, bitrate: str = '192k') -> str
def batch_normalize(self, input_files: List[str], output_dir: str,
method: str = 'rms', target_dbfs: float = -20.0) -> List[str]
Normalization Methods
Peak Normalization
- Scales audio so highest peak reaches target level
- Preserves dynamic range
- Good for preventing clipping
- Target: typically -1.0 to -3.0 dBFS
RMS Normalization
- Scales audio so average level reaches target
- Better for perceived loudness matching
- Good for podcasts and speech
- Target: typically -20.0 to -23.0 dBFS
LUFS Matching
- Integrated Loudness Units relative to Full Scale
- Broadcast standard (EBU R128, ITU BS.1770)
- Target: -23 LUFS (broadcast), -16 LUFS (streaming)
Best Practices
For Podcasts:
normalizer.normalize_rms(target_dbfs=-19.0) # Speech clarity
For Music:
normalizer.normalize_peak(target_dbfs=-1.0) # Preserve dynamics
For Broadcast:
normalizer.normalize_rms(target_dbfs=-23.0) # EBU R128 compliance
Use Cases
- Podcast Production: Consistent volume across episodes
- Music Playlists: Even loudness for continuous playback
- Audiobooks: Standardized narration levels
- Conference Recordings: Normalize different speakers
- Video Production: Match audio levels before mixing
Limitations
- Does not apply dynamic compression (use separate compressor)
- Does not remove DC offset (pre-processing recommended)
- Peak normalization won't match perceived loudness
- Doesn't fix clipped audio (distortion is permanent)