Music Player Demo for RT-Thread

LVGL音乐播放器演示示例（RT-Thread定制版）

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.

如何使用这个Demo

• 在lv_conf.h中增加宏定义#define LV_USE_DEMO_RTT_MUSIC 1

• 如果想要自动播放的话，可以增加宏定义#define LV_DEMO_RTT_MUSIC_AUTO_PLAY 1

• 如果想要让demo循环反复播放，需要增加宏定义#define LV_DEMO_RTT_MUSIC_AUTO_PLAY_FOREVER 1 （如果不定义这个，在只定义 #define LV_DEMO_RTT_MUSIC_AUTO_PLAY 1 的情况下，默认是自动播放40秒，显示平均FPS结果，然后停住）

• lv_conf.h文件涉及到本demo的宏定义配置示例：

    /* music player demo */
    #include <rtconfig.h>
    
    #define LV_HOR_RES_MAX              LCD_WIDTH
    #define LV_VER_RES_MAX              LCD_HEIGHT
    #define LV_USE_DEMO_RTT_MUSIC       1
    #define LV_DEMO_RTT_MUSIC_AUTO_PLAY 1
    #define LV_FONT_MONTSERRAT_12       1
    #define LV_FONT_MONTSERRAT_16       1
    #define LV_COLOR_SCREEN_TRANSP      1

• 调用lv_demo_music()函数：例程

  void lv_user_gui_init(void)
  {
      extern void lv_demo_music(void);
      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