# Music visualizer

> A music visualizer in Python — spectrum analyzers, a radial spectrum, a spectrogram, an oscilloscope and VU meters whose look changes live, fed by a song or the microphone.

Source: https://albakore.github.io/pyzed/audio/demos/visualizer/

(Image: A visualizer cycling through looks: blocks, bars, filled, mirror and line spectrums, a radial one, a spectrogram, a scope and an analog VU meter)

Every analyzer of Pyzed in one window: [`examples/audio/visualizer.py`](https://github.com/albakore/pyzed/blob/main/examples/audio/visualizer.py).

```bash
python examples/audio/visualizer.py
```

It plays a short groove made with the engine (a sequenced bass, kick, snare, hats and chords).
Switch the source to **Microphone** to see your own voice. The panel on the left changes the main
spectrum live: its look (`variant`), its colors (`colors`), how many bands it has, how fast
the bars fall and whether the peaks stay.

## How it is built

- `demo_song(engine)` builds the groove: a `clock` drives a `sequencer` for the bass and
  another one for the snare, and its beat output strikes the kick. Everything goes through a
  `scope` module before the speakers, so it can be analyzed.
- Each frame, the view asks that module for its analysis, computed in Rust:

```python
mags = tap.spectrum(512)      # 512 bands, 20 Hz to 24 kHz, in dB
rms, peak = tap.level()
wave = tap.scope(2048)        # the last 2048 samples
```

- The same `mags` feed a [`Spectrum`](https://albakore.github.io/pyzed/audio/components/spectrum/) in two looks and a
  [`Spectrogram`](https://albakore.github.io/pyzed/audio/components/spectrogram/); `wave` feeds a
  [`Scope`](https://albakore.github.io/pyzed/audio/components/scope/); the levels feed two
  [`VuMeter`](https://albakore.github.io/pyzed/audio/components/vu-meter/)s.

When the source is the microphone, the song's output is muted so the speakers do not feed back
into the microphone.