(1)Raspberry Pi 音频设置

安装声音服务

sudo apt-get install alsa-utils

加载驱动

sudo modprobe snd_bcm2835

编译DEMO

cd /opt/vc/src/hello_pi/

./rebuild.sh

测试DEMO

cd hello_audio

3.5毫米输出

./hello_audio.bin

HDMI输出

./hello_audio.bin 1

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命令行播放器：

sudo apt-get install mplayer

GUI播放器：

sudo apt-get install smplayer

播放MP3

mplayer -ao alsa test.mp3

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调节音量

GUI模式

alsamixer

命令行模式

amixer

amixer sset PCM 80%

amixer --help

Usage: amixer [command]

Available options:

-h,--help       this help

-c,--card N     select the card

-D,--device N   select the device, default 'default'

-d,--debug      debug mode

-n,--nocheck    do not perform range checking

-v,--version    print version of this program

-q,--quiet      be quiet

-i,--inactive   show also inactive controls

-a,--abstract L select abstraction level (none or basic)

-s,--stdin      Read and execute commands from stdin sequentially

Available commands:

scontrols       show all mixer simple controls

scontents       show contents of all mixer simple controls (default command)

sset sID P      set contents for one mixer simple control

sget sID        get contents for one mixer simple control

controls        show all controls for given card

contents        show contents of all controls for given card

cset cID P      set control contents for one control

cget cID        get control contents for one control

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