Template:SelectAudio

Set Audio Device

If your system has multiple audio devices such as HDMI-Audio, 3.5mm audio jack and I2S-Codec you can set system's default audio device by running the following commands.

• After your board is booted run the following commands to install alsa packages:

$ apt-get update
$ apt-get install libasound2
$ apt-get install alsa-base
$ apt-get install alsa-utils

• 安装好需要的库后，查看系统当前所有的声卡设备的序列号。这里假设aplay的输出如下, 并不是真实情况, 请根据实际情况进行相对应的修改:

$ aplay -l
card 0: HDMI
card 1: 3.5mm codec
card 2: I2S codec

上面的信息表示card 0代表HDMI-Audio，card 1代表3.5mm耳机座, card 2代表I2S-Codec，修改配置文件/etc/asound.conf如下表示选择HDMI-Audio:

pcm.!default {
    type hw
    card 0
    device 0
}
 
ctl.!default {
    type hw
    card 0
}

如果将card 0修改为card 1, 则表示选择3.5mm耳机座, 以此类推。
拷贝一首 .wav 格式的音乐到开发板上，播放音乐：

$ aplay /root/Music/test.wav

可以听见从系统默认的音频设备里输出音频。