摄像头模组

Neardi 支持的摄像头如下：

[ov13855]
[os04a10]

ov13855实践

固件可以通过编译SDK获得，也可以通过 LKD3588 处下载固件，确保下载的固件包含ov13855功能。

SDK编译

选择配置

./build.sh lunch BoardConfig-rk3588-neardi-linux-lkd3588-f0.mk

BoardConfig-rk3588-neardi-linux-lkd3588-f0.mk 对应 kernel/arch/arm64/boot/dts/rockchip/rk3588-neardi-linux-lkd3588-f0.dts

rk3588-neardi-linux-lkd3588-f0.dts确保ov13855的驱动打开，如下：

#include "rk3588-neardi-linux-ld160-x0.dtsi"  
#include "rk3588-linux.dtsi"  
...  
#include "rk3588-neardi-linux-ld160-ov13855-os04a10-dphy0.dtsi"  //dphy0  
#include "rk3588-neardi-linux-ld160-ov13855-os04a10-dphy1.dtsi"  //dphy1  
...  
};

编译 kernel

./build.sh kernel

具体编译详见Ubuntu系统编译章节。

硬件连接

LKD3588连接ov13855

Gstreamer打开摄像头

查看摄像头节点

neardi@LPA3588:~$ v4l2-ctl --list-devices  
  
rkisp_mainpath (platform:rkisp0-vir0):  
	/dev/video22  
	/dev/video23  
	/dev/video24  
	/dev/video25  
	/dev/video26  
	/dev/video27  
	/dev/video28  
	/dev/media2  
  
rkisp_mainpath (platform:rkisp1-vir1):  
	/dev/video31  
	/dev/video32  
	/dev/video33  
	/dev/video34  
	/dev/video35  
	/dev/video36  
	/dev/video37  
	/dev/media3

找到mainpath，节点分别是/dev/video22和/dev/video31

使用GStreamer打开video22

gst-launch-1.0 v4l2src device=/dev/video22 ! video/x-raw,format=NV12,width=800,height=600, framerate=30/1 ! fpsdisplaysink

create start_gst_capture.c

  #include <stdio.h>  
  #include <stdlib.h>  
  #include <unistd.h>  
  
  int main() {  
      // Define the video device  
      const char *device = "/dev/video22";  
  
      // Set the DISPLAY environment variable (ensure X11 display is set correctly)  
      setenv("DISPLAY", ":0.0", 1);  
  
      // Prepare the gst-launch-1.0 command to capture video and display fps  
      char command[256];  
      snprintf(command, sizeof(command),  
               "gst-launch-1.0 v4l2src device=%s ! video/x-raw,format=NV12,width=800,height=600,framerate=30/1 ! fpsdisplaysink",  
               device);  
        
      // Print the command to be executed (for debugging)  
      printf("Executing: %s\n", command);  
  
      // Execute the command using system() function  
      int ret = system(command);  
      if (ret == -1) {  
          perror("Failed to execute gst-launch-1.0");  
      }  
  
      return 0;  
  }

gcc gst_video_capture.c -o gst_video_capture  
./gst_video_capture

使用GStreamer打开video31

gst-launch-1.0 v4l2src device=/dev/video31 ! video/x-raw,format=NV12,width=800,height=600, framerate=30/1 ! fpsdisplaysink

create start_gst_capture.c

  #include <stdio.h>  
  #include <stdlib.h>  
  #include <unistd.h>  
  
  int main() {  
      // Define the video device  
      const char *device = "/dev/video31";  
  
      // Set the DISPLAY environment variable (ensure X11 display is set correctly)  
      setenv("DISPLAY", ":0.0", 1);  
  
      // Prepare the gst-launch-1.0 command to capture video and display fps  
      char command[256];  
      snprintf(command, sizeof(command),  
               "gst-launch-1.0 v4l2src device=%s ! video/x-raw,format=NV12,width=800,height=600,framerate=30/1 ! fpsdisplaysink",  
               device);  
        
      // Print the command to be executed (for debugging)  
      printf("Executing: %s\n", command);  
  
      // Execute the command using system() function  
      int ret = system(command);  
      if (ret == -1) {  
          perror("Failed to execute gst-launch-1.0");  
      }  
  
      return 0;  
  }

gcc gst_video_capture.c -o gst_video_capture  
./gst_video_capture

执行成功：

FAQ

摄像头显示空白界面

不返回图像

neardi@LPA3588:~$ gst-launch-1.0 v4l2src device=/dev/video22 ! \  
> video/x-raw,format=NV12,width=800,height=600, framerate=30/1 ! \  
> fpsdisplaysink  
Setting pipeline to PAUSED ...  
Pipeline is live and does not need PREROLL ...  
Pipeline is PREROLLED ...  
Setting pipeline to PLAYING ...  
New clock: GstSystemClock

检查摄像头是否接好。
更换FPC线或摄像头。

摄像头打开失败

neardi@LPA3588:~$ gst-launch-1.0 v4l2src device=/dev/video22 ! \  
> video/x-raw,format=NV12,width=800,height=600, framerate=30/1 ! \  
> fpsdisplaysink  
Setting pipeline to PAUSED ...  
Pipeline is live and does not need PREROLL ...  
Pipeline is PREROLLED ...  
Setting pipeline to PLAYING ...  
New clock: GstSystemClock  
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Failed to allocate required memory.  
Additional debug info:  
../sys/v4l2/gstv4l2src.c(800): gst_v4l2src_decide_allocation (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:  
Buffer pool activation failed  
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data stream error.  
Additional debug info:  
../libs/gst/base/gstbasesrc.c(3127): gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:  
streaming stopped, reason not-negotiated (-4)  
Execution ended after 0:00:00.011081484  
Setting pipeline to NULL ...  
Freeing pipeline ...

使用v4l2-ctl工具抓图测试

抓取输出的 1 帧 NV12 数据保存到/tmp/nv12.bin，分辨率为 1920x1080。在保存数据前，先丢弃前面 3 帧(即前面 3 帧虽然返回给 userspace，但不保存到文件)。

shell  
v4l2-ctl -d /dev/video22  --set-fmt-video=width=1920,height=1080,pixelformat=NV12  --stream-mmap=3  --stream-skip=3  --stream-to=/tmp/nv12.bin  --stream-count=1  --stream-poll

-d，指定操作对象为/dev/video0设备。
--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
--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-skip，指定丢弃(不保存到文件)前 3 帧。
--stream-to，指定帧数据保存的文件路径。
--stream-count，指定抓取的帧数，不包括--stream-skip 丢弃的数量。
--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。

抓图正常返回结果：

<<<<

抓图异常返回结果：

could not open /camera.out for writing  
		VIDIOC_STREAMON returned -1 (Operation not permitted)

检查FPC线是否接反。
检查FPC线是否松动。
检查摄像头是否接好。
更换FPC线或摄像头。

ov13855实践​

SDK编译​

选择配置​

编译 kernel​

硬件连接​

Gstreamer打开摄像头​

查看摄像头节点​

使用GStreamer打开video22​

使用GStreamer打开video31​

FAQ​

摄像头显示空白界面​

摄像头打开失败​