Camera | 3.瑞芯微平台MIPI摄像头常用调试命令

Camera | 1.Camera基础知识

Camera | 2.MIPI、CSI基础

前面2篇我们讲解了camera的一些基础概念和知识。

本文主要讲述在瑞芯微平台上摄像头开发常用的调试命令。

0、环境

soc??:?rk3568???
board:?EVB1-DDR4-V10
软??件：Android?11
Linux：4.19.232
Camera:ov13850

1. v4l2-utils工具包

v4l-utils工具是由Linux维护的V4L2开发工具包。

它提供了一套用于配置V4L2子设备属性的V4L2和媒体框架相关工具,测试V4L2设备,并提供开发库,如libv4l2等等。

v4l-utils工具包主要包含两个常用工具，分别是media-ctl、v4l2-ctl

瑞芯微的SDK在Buildroot固件中，已经编译好了v4l2-utils软件包里面的工具（Android通常默认支持）。

ubuntu系统安装方法：

peng@ubuntu:~$?sudo?apt?install?v4l-utils

2. media-ctl

media-ctl是v4l2-utils包中的一个工具，主要用来查看、配置Media Framework的各Entity的信息，如格式、裁剪、链接使能等。

V4l2-ctl 工具则是针对/dev/video0，/dev/video1 等 video设备，它在 video 设备上进行 set_fmt，reqbuf(申请buf)，qbuf(送buf回队列)，dqbuf(从队列取出buf)，stream_on，stream_off 等一系列操作。

?n为4的倍数(0,1,2,3…)
?/dev/videon+0：视频输出?SP主通道
?/dev/videon+1：视频输出?MP自身通道
?/dev/videon+2：3A统计
?/dev/videon+3：3A参数设置

1）找到video设备

拓扑结构中有多个的Entity，一些是sub device，一些是video device。前者对应的设备节点是/dev/v4l-subdev，后者对应的是/dev/video。多个的video device中，最常关注的是哪个设备可以输出图像。

$?media-ctl?-d?/dev/media0?-e?"rkisp_selfpath"
/dev/video1
$?media-ctl?-d?/dev/media0?-e?"rkisp_mainpath"
/dev/video0

上面两个命令分别显示出/dev/media0这个链路中，RKISP的SP及MP节点的设备路径。RKISP有两个视频输出设备，它们都能输出图像。

2）显示拓扑结构

使用以下命令可以显示拓扑结构：

$?media-ctl?-p?-d?/dev/media0

主要关注的是有没有找到Sensor的Entity。如果没有找到Sensor的Entity，说明Sensor注册有问题，请按FAQ文档排查。

例如，开发板上接上ov13850摄像头后可以看到如下的输出：

rk3568_r:/?#?media-ctl?-d?/dev/media0?-p???????????????
media-ctl?-d?/dev/media0?-p????????????????????????????
Opening?media?device?/dev/media0???????????????????????
Enumerating?entities???????????????????????????????????
Found?13?entities??????????????????????????????????????
Enumerating?pads?and?links?????????????????????????????
Media?controller?API?version?0.0.255???????????????????
???????????????????????????????????????????????????????
Media?device?information???????????????????????????????
------------------------???????????????????????????????
driver??????????rkisp-vir0?????????????????????????????
model???????????rkisp0?????????????????????????????????
serial?????????????????????????????????????????????????
bus?info???????????????????????????????????????????????
hw?revision?????0x0????????????????????????????????????
driver?version??0.0.255????????????????????????????????
???????????????????????????????????????????????????????
Device?topology????????????????????????????????????????
-?entity?1:?rkisp-isp-subdev?(4?pads,?7?links)?????????
????????????type?V4L2?subdev?subtype?Unknown???????????
????????????device?node?name?/dev/v4l-subdev0??????????
????????pad0:?Sink?????????????????????????????????????
????????????????[fmt:SBGGR10/2112x1568?????????????????
?????????????????crop.bounds:(0,0)/2112x1568???????????
?????????????????crop:(0,0)/2112x1568]?????????????????
????????????????<-?"rkisp-csi-subdev":1?[ENABLED]??????
????????????????<-?"rkisp_rawrd0_m":0?[]???????????????
????????????????<-?"rkisp_rawrd2_s":0?[]???????????????
????????pad1:?Sink?????????????????????????????????????
????????????????<-?"rkisp-input-params":0?[ENABLED]????
????????pad2:?Source???????????????????????????????????
????????????????[fmt:YUYV2X8/2112x1568?????????????????
?????????????????crop.bounds:(0,0)/2112x1568???????????
?????????????????crop:(0,0)/2112x1568]?????????????????
????????????????->?"rkisp_mainpath":0?[ENABLED]????????
????????????????->?"rkisp_selfpath":0?[ENABLED]????????
????????pad3:?Source???????????????????????????????????
????????????????->?"rkisp-statistics":0?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?6:?rkisp-csi-subdev?(6?pads,?5?links)?????????
????????????type?V4L2?subdev?subtype?Unknown???????????
????????????device?node?name?/dev/v4l-subdev1??????????
????????pad0:?Sink?????????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????<-?"rockchip-csi2-dphy0":1?[ENABLED]???
????????pad1:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rkisp-isp-subdev":0?[ENABLED]??????
????????pad2:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rkisp_rawwr0":0?[ENABLED]??????????
????????pad3:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????pad4:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rkisp_rawwr2":0?[ENABLED]??????????
????????pad5:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rkisp_rawwr3":0?[ENABLED]??????????
???????????????????????????????????????????????????????
-?entity?13:?rkisp_mainpath?(1?pad,?1?link)????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video0??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-isp-subdev":2?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?19:?rkisp_selfpath?(1?pad,?1?link)????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video1??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-isp-subdev":2?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?25:?rkisp_rawwr0?(1?pad,?1?link)??????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video2??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-csi-subdev":2?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?31:?rkisp_rawwr2?(1?pad,?1?link)??????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video3??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-csi-subdev":4?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?37:?rkisp_rawwr3?(1?pad,?1?link)??????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video4??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-csi-subdev":5?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?43:?rkisp_rawrd0_m?(1?pad,?1?link)????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video5??????????????
????????pad0:?Source???????????????????????????????????
????????????????->?"rkisp-isp-subdev":0?[]?????????????
???????????????????????????????????????????????????????
-?entity?49:?rkisp_rawrd2_s?(1?pad,?1?link)????????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video6??????????????
????????pad0:?Source???????????????????????????????????
????????????????->?"rkisp-isp-subdev":0?[]?????????????
???????????????????????????????????????????????????????
-?entity?55:?rkisp-statistics?(1?pad,?1?link)??????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video7??????????????
????????pad0:?Sink?????????????????????????????????????
????????????????<-?"rkisp-isp-subdev":3?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?61:?rkisp-input-params?(1?pad,?1?link)????????
?????????????type?Node?subtype?V4L?????????????????????
?????????????device?node?name?/dev/video8??????????????
????????pad0:?Source???????????????????????????????????
????????????????->?"rkisp-isp-subdev":1?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?67:?rockchip-csi2-dphy0?(2?pads,?2?links)?????
?????????????type?V4L2?subdev?subtype?Unknown??????????
?????????????device?node?name?/dev/v4l-subdev2?????????
????????pad0:?Sink?????????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????<-?"m00_b_ov13850?4-0010":0?[ENABLED]??
????????pad1:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rkisp-csi-subdev":0?[ENABLED]??????
???????????????????????????????????????????????????????
-?entity?70:?m00_b_ov13850?4-0010?(1?pad,?1?link)??????
?????????????type?V4L2?subdev?subtype?Sensor???????????
?????????????device?node?name?/dev/v4l-subdev3?????????
????????pad0:?Source???????????????????????????????????
????????????????[fmt:SBGGR10/4224x3136]????????????????
????????????????->?"rockchip-csi2-dphy0":0?[ENABLED]???

从entity70信息中可以看到：

应用程序

拓扑结构图如下：【后面文章会详细讲解该结构图，请收藏本系列文章】

3）修改Entity的format、size

举例一，ov3850摄像头支持多个分辨率的输出，默认为1920x1080。现将输出分辨率改为640x480：

media-ctl?-d/dev/media0
--set-v4l2'?"m00_b_ov13850?4-0010":0[fmt:SBGGR10/640x480]'

修改ov3850输出后，rkisp-isp-subdev的大小及video device crop也相应要修改。因为后级的大小不能大于前级的大小。

~/>$?media-ctl?-d/dev/media0?--set-v4l2?'?"rkisp-isp-subdev":0[fmt:SBGGR10/640x480]'
~/>$?media-ctl?-d/dev/media0?--set-v4l2?'?"rkisp-isp-subdev":0[crop:?(0,?0)/640x480]'
~/>$?media-ctl?-d/dev/media0?--set-v4l2?'?"rkisp-isp-subdev":2[crop:?(0,?0)/640x480]'
~/>$?v4l2-ctl?-d/dev/video0
--set-selection=target=crop,?top=0,?left=0,?width=640,?height=480

3. v4l2-ctl

v4l2-ctl的帮助信息查看：

[root@RK356X:~]#?v4l2-ctl?-h
General/Common?options:
--all???????????display?all?information?available
-C,?--get-ctrl?<ctrl>[,<ctrl>...]
get?the?value?of?the?controls?[VIDIOC_G_EXT_CTRLS]
-c,?--set-ctrl?<ctrl>=<val>[,<ctrl>=<val>...]
set?the?value?of?the?controls?[VIDIOC_S_EXT_CTRLS]
-D,?--info????????show?driver?info?[VIDIOC_QUERYCAP]
-d,?--device?<dev>?use?device?<dev>?instead?of/dev/video0
if?<dev>?starts?with?a?digit,?then?/dev/video<dev>?is?used
-e,?--out-device?<dev>?use?device?<dev>?for?output?streams?instead?of?the?default?device?as?set?with?--device
if?<dev>?starts?with?a?digit,?then?/dev/video<dev>?is?used
-h,?--help?display?this?help?message
…………

也可以进入以下网站：

https://www.mankier.com/1/v4l2-ctl

1）列出所有设备

命令：

v4l2-ctl?--list-devices

执行结果：

rk3568_r:/?#?v4l2-ctl?--list-devices
v4l2-ctl?--list-devices
rkisp-statistics?(platform:?rkisp):
????????/dev/video7
????????/dev/video8

rkisp_mainpath?(platform:rkisp-vir0):
????????/dev/video0
????????/dev/video1
????????/dev/video2
????????/dev/video3
????????/dev/video4
????????/dev/video5
????????/dev/video6

2）指定设备的预览支持格式

v4l2-ctl?--list-formats-ext?--device?/dev/video0
v4l2-ctl?--list-formats-ext?--device?/dev/video1

rk3568_r:/?#?v4l2-ctl?--list-formats-ext?--device?/dev/video0???
v4l2-ctl?--list-formats-ext?--device?/dev/video0????????????????
ioctl:?VIDIOC_ENUM_FMT??????????????????????????????????????????
????????Index???????:?0?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'UYVY'????????????????????????????????????
????????Name????????:?UYVY?4:2:2????????????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?1?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'422P'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:2??????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?2?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV16'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:2??????????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?3?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV61'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:2??????????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?4?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YM16'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:2?(N-C)????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?5?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV21'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:0??????????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?6?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV12'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:0??????????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?7?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NM21'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:0?(N-C)????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?8?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NM12'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:0?(N-C)????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?9?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YU12'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:0??????????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?10????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YM24'????????????????????????????????????
????????Name????????:?Planar?YUV?4:4:4?(N-C)????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?11????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'RGGB'????????????????????????????????????
????????Name????????:?8-bit?Bayer?RGRG/GBGB?????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?12????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'GRBG'????????????????????????????????????
????????Name????????:?8-bit?Bayer?GRGR/BGBG?????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?13????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'GBRG'????????????????????????????????????
????????Name????????:?8-bit?Bayer?GBGB/RGRG?????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?14????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'BA81'????????????????????????????????????
????????Name????????:?8-bit?Bayer?BGBG/GRGR?????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?15????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'RG10'????????????????????????????????????
????????Name????????:?10-bit?Bayer?RGRG/GBGB????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?16????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'BA10'????????????????????????????????????
????????Name????????:?10-bit?Bayer?GRGR/BGBG????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?17????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'GB10'????????????????????????????????????
????????Name????????:?10-bit?Bayer?GBGB/RGRG????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?18????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'BG10'????????????????????????????????????
????????Name????????:?10-bit?Bayer?BGBG/GRGR????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?19????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'RG12'????????????????????????????????????
????????Name????????:?12-bit?Bayer?RGRG/GBGB????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?20????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'BA12'????????????????????????????????????
????????Name????????:?12-bit?Bayer?GRGR/BGBG????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?21????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'GB12'????????????????????????????????????
????????Name????????:?12-bit?Bayer?GBGB/RGRG????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?22????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'BG12'????????????????????????????????????
????????Name????????:?12-bit?Bayer?BGBG/GRGR????????????????????
????????????????Size:?Stepwise?32x16?-?2112x1568?with?step?8/8?????????????????????????????????????????????????
rk3568_r:/?#??????????????????????
rk3568_r:/?#?v4l2-ctl?--list-formats-ext?--device?/dev/video1???
v4l2-ctl?--list-formats-ext?--device?/dev/video1????????????????
ioctl:?VIDIOC_ENUM_FMT??????????????????????????????????????????
????????Index???????:?0?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'UYVY'????????????????????????????????????
????????Name????????:?UYVY?4:2:2????????????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?1?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'422P'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:2??????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?2?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV16'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:2??????????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?3?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV61'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:2??????????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?4?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YM16'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:2?(N-C)????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?5?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV21'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:0??????????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?6?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NV12'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:0??????????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?7?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NM21'????????????????????????????????????
????????Name????????:?Y/CrCb?4:2:0?(N-C)????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?8?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'NM12'????????????????????????????????????
????????Name????????:?Y/CbCr?4:2:0?(N-C)????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?9?????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YU12'????????????????????????????????????
????????Name????????:?Planar?YUV?4:2:0??????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?10????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'YM24'????????????????????????????????????
????????Name????????:?Planar?YUV?4:4:4?(N-C)????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?11????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'GREY'????????????????????????????????????
????????Name????????:?8-bit?Greyscale???????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?12????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'XR24'????????????????????????????????????
????????Name????????:?32-bit?BGRX?8-8-8-8???????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?13????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'RGBP'????????????????????????????????????
????????Name????????:?16-bit?RGB?5-6-5??????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??
????????????????????????????????????????????????????????????????
????????Index???????:?14????????????????????????????????????????
????????Type????????:?Video?Capture?Multiplanar?????????????????
????????Pixel?Format:?'FBCG'?(compressed)???????????????????????
????????Name????????:?Rockchip?fbc?gain?????????????????????????
????????????????Size:?Stepwise?32x16?-?1920x1080?with?step?8/8??

3）获取指定设备的所有信息

v4l2-ctl?--all?--device?/dev/video0

设备信息如下：

rk3568_r:/?#?v4l2-ctl?--all?--device?/dev/video0
v4l2-ctl?--all?--device?/dev/video0
Driver?Info:
????????Driver?name??????:?rkisp_v5
????????Card?type????????:?rkisp_mainpath
????????Bus?info?????????:?platform:rkisp-vir0
????????Driver?version???:?1.8.0
????????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??????:?rkisp-vir0
????????Model????????????:?rkisp0
????????Serial???????????:
????????Bus?info?????????:
????????Media?version????:?4.19.255
????????Hardware?revision:?0x00000000?(0)
????????Driver?version???:?4.19.255
Interface?Info:
????????ID???????????????:?0x0300000e
????????Type?????????????:?V4L?Video
Entity?Info:
????????ID???????????????:?0x0000000d?(13)
????????Name?????????????:?rkisp_mainpath
????????Function?????????:?V4L2?I/O
????????Pad?0x01000010???:?Sink
??????????Link?0x02000011:?from?remote?pad?0x1000004?of?entity?'rkisp-isp-subdev':?Data,?Enabled
Priority:?2
Format?Video?Capture?Multiplanar:
????????Width/Height??????:?2112/1568
????????Pixel?Format??????:?'NV12'
????????Field?????????????:?None
????????Number?of?planes??:?1
????????Flags?????????????:
????????Colorspace????????:?Default
????????Transfer?Function?:?Default
????????YCbCr?Encoding????:?Default
????????Quantization??????:?Full?Range
????????Plane?0???????????:
???????????Bytes?per?Line?:?2112
???????????Size?Image?????:?4967424
Crop:?Left?0,?Top?0,?Width?2112,?Height?1568
Selection:?crop,?Left?0,?Top?0,?Width?2112,?Height?1568,?Flags:
Selection:?crop_bounds,?Left?0,?Top?0,?Width?2112,?Height?1568,?Flags:
Selection:?crop,?Left?0,?Top?0,?Width?2112,?Height?1568,?Flags:
Selection:?crop_bounds,?Left?0,?Top?0,?Width?2112,?Height?1568,?Flags:

User?Controls

???????????????????????exposure?0x00980911?(int)????:?min=4?max=3324?step=1?default=1536?value=1536

Image?Source?Controls

??????????????vertical_blanking?0x009e0901?(int)????:?min=192?max=29631?step=1?default=192?value=192
????????????horizontal_blanking?0x009e0902?(int)????:?min=576?max=576?step=1?default=576?value=576?flags=read-only
??????????????????analogue_gain?0x009e0903?(int)????:?min=16?max=248?step=1?default=16?value=16

Image?Processing?Controls

?????????????????link_frequency?0x009f0901?(intmenu):?min=0?max=0?default=0?value=0?flags=read-only
?????????????????????pixel_rate?0x009f0902?(int64)??:?min=0?max=0?step=0?default=0?value=120000000?flags=read-only
???????????????????test_pattern?0x009f0903?(menu)???:?min=0?max=4?default=0?value=0

4）显示摄像头参数

v4l2-ctl?--list-ctrls?--device?/dev/video0
或者
v4l2-ctl?-d?/dev/video0?-l?

显示摄像头参数

rk3568_r:/?#?v4l2-ctl?-d?/dev/video0?-l?????
v4l2-ctl?-d?/dev/video0?-l??
User?Controls???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
???????????????????????exposure?0x00980911?(int)????:?min=4?max=3324?step=1?default=1536?value=1536???
Image?Source?Controls??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
??????????????vertical_blanking?0x009e0901?(int)????:?min=192?max=29631?step=1?default=192?value=192???
????????????horizontal_blanking?0x009e0902?(int)????:?min=576?max=576?step=1?default=576?value=576?flags=read-only?
??????????????????analogue_gain?0x009e0903?(int)????:?min=16?max=248?step=1?default=16?value=16???
Image?Processing?Controls???????????????????????????????????????????????????????????????????????????????????????????????????????
?????????????????link_frequency?0x009f0901?(intmenu):?min=0?max=0?default=0?value=0?flags=read-only?
?????????????????????pixel_rate?0x009f0902?(int64)??:?min=0?max=120000000?step=1?default=120000000?value=120000000?flags=read-only??????
???????????????????test_pattern?0x009f0903?(menu)???:?min=0?max=4?default=0?value=0???

5）增加曝光exposure

exposure值区间为: ?4-3324
命令实例：

v4l2-ctl?-d?/dev/video0?--set-ctrl?exposure=3324

6）增加图片亮度analogue_gain

analogue_gain用于设置显示的图像的亮度

analogue_gain值区间：

16-248

命令实例：

v4l2-ctl?-d?/dev/video0?--set-ctrl?analogue_gain=240

analogue_gain=16现象

analogue_gain=244现象【效果非常明显】

7）使用v4l2-ctl抓帧

v4l2-ctl?-d?/dev/video0?--set-fmt-video=width=800,height=600,pixelformat=NV12?--stream-mmap=3?--stream-to=/sdcard/out.yuv?--stream-skip=9?--stream-count=1
m-mmap=3?--stream-to=/sdcard/out.yuv?--stream-skip=9?--stream-count=1?????????<
<<<<<<<<<?7.51?fps
<

【看到<<<<<<<<< 7.51 fps 说明成功】

参数说明

-d：?摄像头对应设备文件
--set-fmt-video：指定了宽高及pxielformat(用FourCC表示)。NV12即用FourCC表示的pixelformat
--stream-mmap：指定buffer的类型为mmap，即由kernel分配的物理连续的或经过iommu映射的buffer
--stream-to：指定帧数据保存的文件路径
--stream-skip：指定丢弃(不保存到文件)前3帧
--stream-count：指定抓取的帧数，不包括--stream-skip丢弃的数量

其他参数
--set-selection，指定对输入图像进行裁剪。特别是当RKISP1的前级大小发生变化时要保证selection不大于前级输出大小。RKCIF的裁剪则是通过--set-crop参数设置的
--stream-poll，该选项指示v4l2-ctl采用异步IO，即在dqbuf前先用select等等帧数据完成，从而保证dqbuf不阻塞。否则dqbuf将会阻塞直到有数据帧到来

如果支持264的可以编码为h264查看

v4l2-ctl?--device?/dev/video0?--set-fmt-video=width=1920,height=1080,pixelformat=H264?--stream-mmap=3?--stream-to=/sdcard/output?--stream-count=100

v4l2-ctl?--device?/dev/video0?--set-fmt-video=width=1920,height=1080,pixelformat=MJPG?--stream-mmap?--stream-to=/sdcard/output.mjpg?--stream-count=300

8）测试显示信息test_pattern

参数test_pattern，可以用于测试显示图像

命令实例：

v4l2-ctl?-d?/dev/video0?--set-ctrl?test_pattern=0?

test_pattern = 1test_pattern = 2test_pattern = 3

4. 显示图片

上一节，抓取的图片、视频要可以拷贝到ubuntu中借助借助工具ffplay查看。

1）ffplay

FFmpeg是一套可以用来记录、转换数字音频、视频，并能将其转化为流的开源计算机程序。

采用LGPL或GPL许可证。它提供了录制、转换以及流化音视频的完整解决方案。

它包含了非常先进的音频/视频编解码库libavcodec，为了保证高可移植性和编解码质量，libavcodec里很多code都是从头开发的。

ffplay是FFmpeg提供的一个极为简单的音视频媒体播放器（由ffmpeg库和SDL库开发），可以用于音视频播放、可视化分析，提供音视频显示和播放相关的图像信息、音频的波形等信息，也可以用作FFmpeg API的测试工具使用。

由于是基于FFmpeg开发所以ffmpeg支持的视音频格式它基本上都支持，不过ffplay不是图形化界面需要通过CMD命令窗口来操作。

2）官网网站

http://www.ffmpeg.org/ffplay.html

3）ffplay命令选项：

基本格式：?ffplay?[选项]?[‘输入文件’]

主要选项：

-x?width??????强制显示宽带
-y?height??????强制显示高度
-video_size?size????设置帧尺寸?设置帧尺寸大小。
?适用于类似原始YUV等没有包含帧大小(WxH)的视频。
?例如：ffplay?-pixel_format?yuv420p?-video_size?320x240?-framerate?5?yuv420p_320x240.yuv
-pixel_format?format???设置像素格式。
-volume?vol?????设置起始音量。音量范围[0?~100]
-window_title?title???设置窗口标题（默认为输入文件名）
-loop?number?????设置播放循环次数
-showmode?mode?????设置显示模式，可用的模式值：0?显示视频，1?显示音频波形，2?显示音频频谱。缺省为0，如果视频不存在则自动选择2
-vf?filtergraph????设置视频滤镜
-af?filtergraph????设置音频滤镜
-f?fmt???????强制使用设置的格式进行解析。比如-f?s16le?

-fs??????以全屏模式启动
-an??????禁用音频（不播放声音）
-vn??????禁用视频（不播放视频）
-sn??????禁用字幕（不显示字幕）
-nodisp?????关闭图形化显示窗口，视频将不显示
-noborder?????无边框窗口


-t?duration???设置播放视频/音频长度，时间单位如?-ss选项
-ss?pos????跳转到指定的位置，注意时间单位：
??比如：'55'?55?seconds,?
???'12:03:45'?,12?hours,?03?minutes?and?45?seconds,?
???'23.189'?23.189?second


-bytes????????按字节进行跳转（0=off?1=on?-1=auto）。
-seek_interval?interval???自定义左/右键定位拖动间隔（以秒为单位），默认值为10秒（代码没有看到实现）

4）显示图片

将文件**/sdcard/out.yuv从板子通过adb pull**命令拷贝出来，
运行于windows下：

adb?pull?/sdcard/out.yuv

再拷贝到ubuntu中，执行以下命令显示图片【用其他可以打开yuv格式图片的工具也可以】

ffplay?out.yuv?-f?rawvideo?-pixel_format?nv12?-video_size?800x600

掌握了这些命令，我们就可以调试摄像头了。

后面还会继续更新几篇Camera文章，

建议大家订阅本专题！