把音量调到影院模式

幽兰的默认音量是按照个人使用场景设置的，最大音量不是特别大。如果兰友在使用幽兰播放电影，给多人一起看时，可以按下面步骤调大最大音量。

!!!注意，音量值不宜一下子调的太大，以免音量过大，导致耳膜受伤，千万牢记，风险自负!!!

1. 安装i2c-tools

sudo apt install i2c-tools

2. 执行如下命令设置50寄存器

sudo i2cset -f -y 3 0x19 0x50 0xb0 b

这里的0x50对应的是幽兰所用ES8326声音Codec的DAC控制器
REGISTER 0X50 -DAC CONTROL

这里的0xb0代表音量增益，值越大，音量越大，PC模式时是0x97，根据我们的经验，2-3人看电影时，可以调整为0xb0，不要再大!!!

… 0.5dB/step
0xBE - ‘-0.5dB’
0xBF - ‘0dB’
0xC0 - ‘+0.5dB’
…
0xFF - ‘+32dB’
Note: DAC_VOLUME is max gain when DRC enable

3. 执行如下命令确认设置成功

geduer@ulan:~$ sudo i2cdump -f -y 3 0x19 b
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 80 5f c0 05 e0 00 30 ad 4a 0a 1f 1f 09 03 00 ff ?_???.0?J?????..
10: c4 81 00 0c 03 0f 3b 40 02 f0 00 50 7f 0a 88 88 ??.???;@??.P????
20: 88 88 03 10 21 11 44 00 03 33 44 66 ff ff 00 00 ????!?D.?3Df….
30: 00 00 00 00 2c 0c 00 00 00 00 00 00 00 00 00 00 ….,?……….
40: 00 00 00 00 00 00 00 00 00 00 8c 00 00 08 01 15 ……….?..???
50: b0 00 00 00 10 aa d9 95 08 00 00 00 00 00 00 00 ?…?????…….
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …………….
f0: 00 00 00 00 00 00 00 00 00 00 00 1c 40 83 26 00 ...........?@?&.

4. 先戴上耳麦保护耳朵，点击左上角的声音图标，打开声音设置界面，测试音量和对音量进行微调