I.MX6 USB Camera

/*************************************************************************
 *                         I.MX6 USB Camera
 * 说明：
 *     今天购买了个USB Camera，用来测试一下驱动。
 *
 *                                      2017-1-23 深圳 南山平山村 曾剑锋
 ************************************************************************/

一、参考文档：
    . Using a USB Camera with GStreamer
        https://community.nxp.com/docs/DOC-93688
    . Webcam (Linux)
        http://developer.toradex.com/knowledge-base/webcam-(linux)

二、USB Camera配置：
    Device Drivers -> Multimedia support -> Video capture adapters -> V4L USB devices -> <*> USB Video Class (UVC)
    或者
    Device Drivers -> Multimedia support -> Media USB Adapters -> <*> USB Video Class (UVC)

三、识别输出信息：
    [zengjf@root /dev]#  ls /dev/video*
    /dev/video0   /dev/video16  /dev/video17  /dev/video18
    [zengjf@root /dev]#  usb -1.3: new high speed USB device number  using fsl-ehci
    usb -1.3: New USB device found, idVendor=057e, idProduct=030a
    usb -1.3: New USB device strings: Mfr=, Product=, SerialNumber=
    usb -1.3: Product: USB Camera
    usb -1.3: Manufacturer: Guillemot Corporation
    uvcvideo: Found UVC 1.00 device USB Camera (057e:030a)
    input: USB Camera as /devices/platform/fsl-ehci./usb2/-/-1.3/-1.3:1.0/input/input4

    [zengjf@root /dev]#  ls /dev/video*
    /dev/video0   /dev/video1   /dev/video16  /dev/video17  /dev/video18
    [zengjf@root /dev]#  lsusb
    Bus  Device : ID 1d6b:
    Bus  Device : ID 1d6b:
    Bus  Device : ID :005a
    Bus  Device : ID 057e:030a
    [zengjf@root /dev]#