v4l-ctl常用命令

v4l2-ctl -d /dev/video0 --list-formats-ext

查一下分辨率的支持，类似如下输出信息：

root@robot:~# v4l2-ctl -d /dev/video3 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
        Type: Video Capture Multiplanar

        [0]: 'RGBP' (16-bit RGB 5-6-5)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [1]: 'RGB3' (24-bit RGB 8-8-8)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [2]: 'BGR3' (24-bit BGR 8-8-8)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [3]: 'YUYV' (YUYV 4:2:2)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [4]: 'YUV4' (32-bit A/XYUV 8-8-8-8)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [5]: 'NV12' (Y/CbCr 4:2:0)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [6]: 'YM24' (Planar YUV 4:4:4 (N-C))
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [7]: 'XR24' (32-bit BGRX 8-8-8-8)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0
        [8]: 'AR24' (32-bit BGRA 8-8-8-8)
                Size: Discrete 2048x1280
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                Size: Discrete 0x0
                Size: Discrete 0x0

---------------------------------------------------------------------------------

 v4l2-ctl -d /dev/video0 -D

root@robot:~# v4l2-ctl -d /dev/video3 -D
Driver Info:
        Driver name      : mxc-isi-cap
        Card type        : mxc-isi-cap
        Bus info         : platform:32e00000.isi:cap_devic
        Driver version   : 5.10.35
        Capabilities     : 0x84201000
                Video Capture Multiplanar
                Streaming
                Extended Pix Format
                Device Capabilities
        Device Caps      : 0x04201000
                Video Capture Multiplanar
                Streaming
                Extended Pix Format
Media Driver Info:
        Driver name      : mxc-md
        Model            : FSL Capture Media Device
        Serial           :
        Bus info         :
        Media version    : 5.10.35
        Hardware revision: 0x00000000 (0)
        Driver version   : 5.10.35
Interface Info:
        ID               : 0x03000014
        Type             : V4L Video
Entity Info:
        ID               : 0x00000012 (18)
        Name             : mxc_isi.0.capture
        Function         : V4L2 I/O
        Pad 0x01000013   : 0: Sink
          Link 0x02000036: from remote pad 0x100000e of entity 'mxc_isi.0': Data, Enabled

---------------------------------------------------------------------------------

v4l2-ctl -d /dev/video0 --stream-mmap

正常出图时可看到帧号打印

借此判断一下 V4L2 是否正常

root@robot:~# v4l2-ctl -d /dev/video3 --stream-mmap
<<<<<<<<<<< 9.85 fps
<<<<<<<<<< 9.84 fps
<<<<<<<<<< 9.84 fps
<<<<<<<<<< 9.84 fps
<<<<<<<<<< 9.84 fps
<<<<<<<<<< 9.84 fps
<<<<<<<<< 9.84 fps
<<<<<<<<<< 9.84 fps

---------------------------------------------------------------------------------

test_v4l2-ctl.sh

#!/bin/bash

logName=`date +%Y_%m_%d_%H_%M_%S`.log

#echo $logName

v4l2-ctl -d /dev/video0 --stream-mmap |& tee $logName