# Music player demo

## Overview
The music player demo shows what kind of modern, smartphone-like user interfaces can be created on LVGL. It works the best with display with 480x272 or 272x480 resolution. 


![Music player demo with LVGL embedded GUI library](https://github.com/lvgl/lv_examples/blob/master/src/lv_demo_music/screenshot1.gif?raw=true)

## Run the demo
- In `lv_conf.h` or equivalent places set `LV_USE_DEMO_MUSIC 1`
- With `LV_DEMO_MUSIC_AUTO_PLAY` enabled a ~60 sec demo will be played.
- After `lv_init()` and initializing the drivers call `lv_demo_music()`

## How the spectrum animation works
- `assets/spectrum.py` creates an array of spectrum values from a music. 4 band are created with 33 samples/sec: bass, bass-mid, mid, mid-treble.
- The spectrum meter UI does the followings:
	- Zoom the album cover proportionality to the current bass value
	- Display the 4 bands on the left side of a circle by default at 0°, 45°, 90°, 135° 
	- Add extra bars next to the "main bars" with a cosine shape. Add more bars for the lower bands.
	- If there is a large enough bass, add a random offset to the position of the bars. E.g. start from 63° instead of 0°. (bars greater than 180° start again from 0°)
	- If there is no bass, add 1 to the offset of the bars (it creates a "walking" effect)
	- Mirror the bars to the right side of the circle
	
## Using spectrum.py
- install `librosa` with `pip3 install librosa`	
- run `python sectrum.py my_file.mp3`
- see the result in `spectrum.h`