最近做一些目标检测类的工作，涉及到linux系统下用usb摄像头获取画面，然后如何不配置摄像头宽高等参数，只使用默认参数获取画面时，只能获得640*480规格的画面。

虽然一般usb摄像头都支持1920*1080 30帧的规格，但还是希望能够获取不同摄像头的完整参数。查阅了一些资料，做一些记录，如果能帮到其他人那是我的荣幸

工具介绍及安装

v4l2-ctl 是 Linux 系统中用于控制 Video for Linux 2 (V4L2) 设备的命令行工具，主要用于管理摄像头、视频采集卡等多媒体设备的参数和功能。

安装v4l2

sudo apt install v4l-utils

查看设备节点

:~# sudo ls /dev/video*
/dev/video0 /dev/video1 /dev/video2

可以通过插拔摄像头来判断usb摄像头对应的设备号

通过v4l2查看摄像头设备

:~# sudo v4l2-ctl --list-devices
rk_hdmirx (fdee0000.hdmirx-controller):
        /dev/video0

WN-Camera-RGB: WN-Camera-RGB (usb-fc880000.usb-1.2):
        /dev/video1
        /dev/video2
        /dev/media0

查看当前摄像头支持的视频压缩格式

:~# sudo v4l2-ctl -d /dev/video1 --list-formats
ioctl: VIDIOC_ENUM_FMT
        Type: Video Capture

        [0]: 'MJPG' (Motion-JPEG, compressed)
        [1]: 'YUYV' (YUYV 4:2:2)

查看USB摄像头 video1 分辨率信息

:~# sudo v4l2-ctl -d /dev/video1 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
Type: Video Capture
[0]: 'MJPG' (Motion-JPEG, compressed)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 160x120
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 320x240
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 352x288
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 1024x768
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 1280x1024
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 2592x1944
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 2048x1536
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
[1]: 'YUYV' (YUYV 4:2:2)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.200s (5.000 fps)
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.125s (8.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.050s (20.000 fps)
Size: Discrete 960x540
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 2592x1944
Interval: Discrete 0.500s (2.000 fps)
Size: Discrete 2048x1536
Interval: Discrete 0.333s (3.000 fps)

如果只有一个usb摄像头，一般默认是video0，只是我的开发板有点特殊，默认是video1

查看摄像头所有参数

:~# sudo v4l2-ctl -d  /dev/video1 --all
Driver Info:
        Driver name      : uvcvideo
        Card type        : WN-Camera-RGB: WN-Camera-RGB
        Bus info         : usb-fc880000.usb-1.2
        Driver version   : 5.10.110
        Capabilities     : 0x84a00001
                Video Capture
                Metadata Capture
                Streaming
                Extended Pix Format
                Device Capabilities
        Device Caps      : 0x04200001
                Video Capture
                Streaming
                Extended Pix Format
Media Driver Info:
        Driver name      : uvcvideo
        Model            : WN-Camera-RGB: WN-Camera-RGB
        Serial           : 200901010001
        Bus info         : usb-fc880000.usb-1.2
        Media version    : 5.10.110
        Hardware revision: 0x00000001 (1)
        Driver version   : 5.10.110
Interface Info:
        ID               : 0x03000002
        Type             : V4L Video
Entity Info:
        ID               : 0x00000001 (1)
        Name             : WN-Camera-RGB: WN-Camera-RGB
        Function         : V4L2 I/O
        Flags         : default
        Pad 0x01000007   : 0: Sink
          Link 0x02000010: from remote pad 0x100000a of entity 'Extension 4': Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
        Width/Height      : 640/480
        Pixel Format      : 'MJPG' (Motion-JPEG)
        Field             : None
        Bytes per Line    : 0
        Size Image        : 614400
        Colorspace        : sRGB
        Transfer Function : Rec. 709
        YCbCr/HSV Encoding: ITU-R 601
        Quantization      : Default (maps to Full Range)
        Flags             :
Crop Capability Video Capture:
        Bounds      : Left 0, Top 0, Width 640, Height 480
        Default     : Left 0, Top 0, Width 640, Height 480
        Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 640, Height 480, Flags:
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 640, Height 480, Flags:
Streaming Parameters Video Capture:
        Capabilities     : timeperframe
        Frames per second: 30.000 (30/1)
        Read buffers     : 0
                     brightness 0x00980900 (int)    : min=-64 max=64 step=1 default=0 value=0
                       contrast 0x00980901 (int)    : min=0 max=100 step=1 default=37 value=37
                     saturation 0x00980902 (int)    : min=0 max=100 step=1 default=64 value=64
                            hue 0x00980903 (int)    : min=-180 max=180 step=1 default=0 value=0
 white_balance_temperature_auto 0x0098090c (bool)   : default=1 value=1
                          gamma 0x00980910 (int)    : min=100 max=500 step=1 default=300 value=300
                           gain 0x00980913 (int)    : min=1 max=128 step=1 default=64 value=64
           power_line_frequency 0x00980918 (menu)   : min=0 max=2 default=1 value=1
                                0: Disabled
                                1: 50 Hz
                                2: 60 Hz
      white_balance_temperature 0x0098091a (int)    : min=2800 max=6500 step=10 default=4600 value=4600 flags=inactive
                      sharpness 0x0098091b (int)    : min=0 max=100 step=1 default=50 value=50
         backlight_compensation 0x0098091c (int)    : min=0 max=2 step=1 default=0 value=0
                  exposure_auto 0x009a0901 (menu)   : min=0 max=3 default=3 value=3
                                1: Manual Mode
                                3: Aperture Priority Mode
              exposure_absolute 0x009a0902 (int)    : min=50 max=10000 step=1 default=166 value=166 flags=inactive
         exposure_auto_priority 0x009a0903 (bool)   : default=0 value=1

查看usb摄像头详细参数

:~# v4l2-ctl -d /dev/video1 -D
Driver Info:
        Driver name      : uvcvideo
        Card type        : WN-Camera-RGB: WN-Camera-RGB
        Bus info         : usb-fc880000.usb-1.2
        Driver version   : 5.10.110
        Capabilities     : 0x84a00001
                Video Capture
                Metadata Capture
                Streaming
                Extended Pix Format
                Device Capabilities
        Device Caps      : 0x04200001
                Video Capture
                Streaming
                Extended Pix Format
Media Driver Info:
        Driver name      : uvcvideo
        Model            : WN-Camera-RGB: WN-Camera-RGB
        Serial           : 200901010001
        Bus info         : usb-fc880000.usb-1.2
        Media version    : 5.10.110
        Hardware revision: 0x00000001 (1)
        Driver version   : 5.10.110
Interface Info:
        ID               : 0x03000002
        Type             : V4L Video
Entity Info:
        ID               : 0x00000001 (1)
        Name             : WN-Camera-RGB: WN-Camera-RGB
        Function         : V4L2 I/O
        Flags         : default
        Pad 0x01000007   : 0: Sink
          Link 0x02000010: from remote pad 0x100000a of entity 'Extension 4': Data, Enabled, Immutable

查看摄像头MJPG压缩格式所支持的分辨率

:~# sudo v4l2-ctl --list-framesizes=MJPG -d /dev/video1
ioctl: VIDIOC_ENUM_FRAMESIZES
Size: Discrete 640x480
Size: Discrete 160x120
Size: Discrete 320x240
Size: Discrete 352x288
Size: Discrete 640x480
Size: Discrete 800x600
Size: Discrete 1024x768
Size: Discrete 1280x720
Size: Discrete 1280x1024
Size: Discrete 1920x1080
Size: Discrete 2592x1944
Size: Discrete 2048x1536

YUYV同样的方法，调整参数即可

最后

只是自己学习过程中的一些记录，如果对别人有帮助，我很荣幸。如还有问题，可以评论区、私信交流。