VisualHMI audio playback: play_sound series and automatic continuous playback of MP3

Audio Playback API: Plays music files from SD/U-disks, and works with player controls to create a complete music player (play/pause/previous/next/progress bar/volume).

1. API Summary Table

2. Player Control Address Table

3. Traverse SD card songs

musicNameListTb = {}      -- 歌名列表缓存
curPlayIndex = 1

function on_sd_inserted(dir)
  list_dir(dir)           -- 列 SD 卡根目录
end

function on_list_dir(path, filename, type, fsize)
  if type == 1 then
    local ext = string.sub(filename, -4)
    if ext == ".mp3" or ext == ".wav" then
      table.insert(musicNameListTb, filename)
      set_uint16(VT_LW, 0x1005, 1)   -- 有歌标志
    end
  end
end

4. Playback control logic

function on_update(slave, vtype, addr)
  if vtype == VT_LW then
    if addr == 0x1002 then
      local v = get_uint16(VT_LW, 0x1002)
      if v == 1 then
        play_sound("1:/music/"..musicNameListTb[curPlayIndex])
      else
        pause_sound()
      end
    elseif addr == 0x1001 then
      -- 上一首/下一首：切换 curPlayIndex 后重新播放
      local v = get_uint16(VT_LW, 0x1001)
      if v == 1 and curPlayIndex > 1 then
        curPlayIndex = curPlayIndex - 1
      elseif v == 2 and curPlayIndex < #musicNameListTb then
        curPlayIndex = curPlayIndex + 1
      end
      play_sound("1:/music/"..musicNameListTb[curPlayIndex])
    end
  end
end

function on_run(screen)
  updatMisPlayState()     -- 检测播放状态，播完自动下一首
end

Compiled from Guangzhou Dacai Technology VisualHMI development documentation (hmi-doc.gz-dc.com) LUA tutorial "Audio Playback", copyright owned by Dacai Technology.