linux --mplayer播放文件时有强大的电流杂音

vingt

mplayer是使用yum安装的，使用默认音频输出（应该是pluseaudio）,在播放avi、mpg等文件时电流杂音特别大。换了几个音频输出，要不是没有声音，就是依然有电流杂音。
这是怎么回事啊，是不是解码器有问题？
如果是这样的话怎么解决？

用命令行 mplayer **.mpg时输出如下：

==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
AUDIO: 44100 Hz, 2 ch, s16le, 224.0 kbit/15.87% (ratio: 28000->176400)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
Starting playback...
[VD_FFMPEG] Trying pixfmt=0.
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
[VD_FFMPEG] Trying pixfmt=1.
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
[VD_FFMPEG] Trying pixfmt=2.
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
Movie-Aspect is 1.22:1 - prescaling to correct movie aspect.
VO: [xv] 352x288 => 352x288 Planar YV12
A:  14.9 V:  14.9 A-V:  0.002 ct: -0.036 363/363  1%  0%  2.2% 1 0

lurz

运行alsamixer
按F5，逐个选项开关一下，把有问题的关了。