你好，
通过aplay命令播放，line out输出是ok的
执行aplay -l输出结果是:
**** List of PLAYBACK Hardware Devices ****
card 0: SOUND0 [TI81XX SOUND0], device 1: AIC3X tlv320aic3x-hifi-1 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: SOUND1 [TI81XX SOUND1], device 0: hdmi HDMI-DAI-CODEC-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
所以我这样播放，aplay -Dhw:0,1 ccav.wav，这样line out的左右声道都是有声音的，正常。我用下面的脚步初始化
### set audio volume ###
amixer cset name="PCM Playback Volume" 100%
amixer cset name="PGA Capture Volume" 100%
### select DAC channel for output ###
### 0 used for line_out and headset_out;1 used for line_out;2 used for headset_o
amixer cset name="Left DAC Mux" 1
amixer cset name="Right DAC Mux" 1
amixer sset 'Right PGA Mixer Mic3L' off
amixer sset 'Right PGA Mixer Mic3R' off
amixer sset 'Left PGA Mixer Mic3L' off
amixer sset 'Left PGA Mixer Mic3R' off
amixer sset 'Right PGA Mixer Line1R' on
amixer sset 'Right PGA Mixer Line1L' on
amixer sset 'Left PGA Mixer Line1R' on
amixer sset 'Left PGA Mixer Line1L' on
硬件是LINE1P（10脚）和LINE1RP（12脚）脚分别连到LINE in的左声道和右声道
LEFT_LO+，LEFT_LO-(27和28脚)接到LINE out的左声道，RIGHT_LO+和RIGHT_LO-(29和30脚)连到LINE out的右声道。
我的程序采集音频之后在vlc中听是正常的，就是line out输出的右声道声音特别小，要开到最大才能听到一点。