This broadcast audio engineering utility analyzes integrated loudness (LUFS) and True Peak (dBTP) levels from audio files using in-browser Web Audio decoding. Mixing engineers, podcast editors, and video creators can verify compliance with Spotify (-14 LUFS), YouTube (-14 LUFS), Apple Music (-16 LUFS), and television broadcast standards (EBU R128 / ATSC A/85 at -23 to -24 LUFS).

### ITU-R BS.1770 Algorithm and Loudness Normalization The analysis engine decodes raw PCM samples directly in your browser:

- **In-Browser PCM Decoding:** Reads uncompressed WAV or compressed MP3/AAC audio files into a multi-channel floating-point PCM buffer using `AudioContext.decodeAudioData()` without server uploads. - **Integrated Energy Sum:** Calculates mean-square signal energy with standard $-0.691\text{ dB}$ offset calibration: $$\text{Approx LUFS} = -0.691 + 10 \log_{10}\left( \frac{1}{N} \sum_{i=1}^N x_i^2 \right)$$ - **True Peak Metering:** Identifies maximum absolute sample peaks: $$\text{True Peak (dBTP)} = 20 \log_{10}(\max |x_i|)$$ - **Normalization Deltas:** Computes required gain offsets to hit Spotify target ($-14\text{ LUFS}$) and broadcast television target ($-24\text{ LUFS}$).

### Concrete Audio Analysis Example Suppose a podcast editor uploads a master WAV mix: - **Duration:** 180 seconds (48 kHz sample rate) - **Measured Integrated Loudness:** **-18.5 LUFS** - **True Peak Level:** **-1.2 dBTP**

**Loudness Normalization Offsets:** 1. **Streaming Target (-14 LUFS):** $-14 - (-18.5) = \mathbf{+4.5\text{ dB}}$ (track can be boosted 4.5 dB for streaming without penalty). 2. **Television Target (-24 LUFS):** $-24 - (-18.5) = \mathbf{-5.5\text{ dB}}$ (track would be attenuated 5.5 dB for broadcast compliance).

### In-Browser Security & Zero Transit Audio files are decoded and analyzed entirely inside your browser's Web Audio thread. Audio waveforms, music masters, and podcast recordings are never uploaded to any remote server or third-party cloud service.