apt-get update
apt-get install libavcodec-extra
apt-get install libav-tools
apt-get install v4l-utils
查看usb摄像头：
v4l2-ctl –list-devices
输出如下则证明摄像头正常：
root@cubietruck:~# v4l2-ctl -list-devices
Video input set to 0 (Camera 1: ok)
brightness (int) : min=-64 max=64 step=1 default=0 value=0
contrast (int) : min=0 max=95 step=1 default=34 value=34
saturation (int) : min=0 max=128 step=1 default=42 value=42
hue (int) : min=-40 max=40 step=1 default=0 value=0
white_balance_temperature_auto (bool) : default=1 value=1
gamma (int) : min=72 max=500 step=1 default=106 value=106
power_line_frequency (menu) : min=0 max=2 default=1 value=1
sharpness (int) : min=0 max=10 step=1 default=7 value=7
backlight_compensation (int) : min=0 max=1 step=1 default=0 value=0
exposure_auto (menu) : min=0 max=3 default=3 value=3
exposure_auto_priority (bool) : default=0 value=1
brightness (int) : min=-64 max=64 step=1 default=0 value=0
contrast (int) : min=0 max=95 step=1 default=34 value=34
saturation (int) : min=0 max=128 step=1 default=42 value=42
hue (int) : min=-40 max=40 step=1 default=0 value=0
white_balance_temperature_auto (bool) : default=1 value=1
gamma (int) : min=72 max=500 step=1 default=106 value=106
power_line_frequency (menu) : min=0 max=2 default=1 value=1
sharpness (int) : min=0 max=10 step=1 default=7 value=7
backlight_compensation (int) : min=0 max=1 step=1 default=0 value=0
开始推送流媒体：
avconv -f video4linux2 -r 25 -s 640X480 -i /dev/video0 -f flv rtmp://{ip}/live/
