V4L2 on Jetson TX2

Autonomous Machines Jetson & Embedded Systems Jetson TX2
21

Thanks JerryChang!
That worked!

22

I am writing a video with

nvgstcapture -m 2 -k 2 -w 10

Is there a chance to use autofocus to increase the quality ?

Recorded sample:
https://drive.google.com/file/d/0B86kh-1GJW29T3ItOG1CYnJZZm8/view?usp=sharing

23

is there a way to get the video captured with guvcview?

ed to query video capabilities: Inappropriate ioctl for device
libv4l2: error getting capabilities: Inappropriate ioctl for device
V4L2_CORE: ERROR opening V4L2 interface for /dev/v4l-subdev0
Failed to query video capabilities: Inappropriate ioctl for device
libv4l2: error getting capabilities: Inappropriate ioctl for device
V4L2_CORE: ERROR opening V4L2 interface for /dev/v4l-subdev1
V4L2_CORE: Unable to find parent usb device.V4L2_CORE: (UVCIOC_CTRL_MAP) Error: Inappropriate ioctl for device

Screenshot from 2017-07-23 10-33-10.png
Screenshot from 2017-07-23 10-33-10.png1280×1024 384 KB

24

@Andrey
The onboard reference sensor didn’t have focus. Does your sensor module have focus?

25

You can try follow below thread to use video loopback

26

Thank you for sharing the link.
I’ve separated the question into a separate thread [url]https://devtalk.nvidia.com/default/topic/1019504/jetson-tx2/how-to-create-loopback-device-for-nvcamerasrc-for-tx2-/[/url]

27

ShaneCCC:
finally it created /dev/video0 device with the method [partially working]

# aptitude install v4l2loopback-source module-assistant
# module-assistant auto-install v4l2loopback-source

Is there any chance to redirect signal from the onboard camera to the /video0 device for it can be used with ordinary internet browser as a camera?

Screenshot from 2017-09-06 18-23-53.png
Screenshot from 2017-09-06 18-23-53.png1280×1024 153 KB

28

finally I managed to get it that way with supplied by colleague .ko file:

insmod v4l2loopback.ko devices=10
root@tegra-ubuntu:/home/nvidia/v4l2loopback# ls /dev/video* -l
crw-rw----+ 1 root video 81,  2 Sep  6 19:31 /dev/video0
crw-rw----+ 1 root video 81,  3 Sep  6 20:51 /dev/video1
crw-rw----+ 1 root video 81,  4 Sep  6 20:51 /dev/video2
crw-rw----+ 1 root video 81,  5 Sep  6 20:51 /dev/video3
crw-rw----+ 1 root video 81,  6 Sep  6 20:51 /dev/video4
crw-rw----+ 1 root video 81,  7 Sep  6 20:51 /dev/video5
crw-rw----+ 1 root video 81,  8 Sep  6 20:51 /dev/video6
crw-rw----+ 1 root video 81,  9 Sep  6 20:51 /dev/video7
crw-rw----+ 1 root video 81, 10 Sep  6 20:51 /dev/video8
29

now the issue is to make the flow from the onboard camera to be present at one of the created virtual devices

30

Hi JerryChang

when I input v4l2 cmmand , prompt system can not support , how can I add v4l2-ctl moudles

v4l2-ctl -d /dev/video0 --stream-mmap --stream-count=1 --stream-to=test.raw

-bash: v4l2-ctl: command not found

B/R

31

I would use insmod + v4l2loopback. I do use it actually. It returned the only way I can work with v4l2.
Regards
v4l2kernel.tar.gz (254 KB)

32

You can try install the v4l-utils or get the source from below link to build it yourself.

https://launchpad.net/ubuntu/xenial/+source/v4l-utils

33

thanka alot

34

how to make nvgstcapture back to normal from upside-down?

35

try the ro:2 for the rotate 180 degrees.

36

like that?

nvgstcapture -m 2 -k 2 -w 10 ro:2
37

it wont affect the rotation that way as it seems to me

38

Try below command.

nvgstcapture --orientation=2
39

thank you

nvgstcapture --orientation=0

did the trick

40

Hey ShaneCCC,

i try to run yolo dakrnet with the onboard cam of a jetson tx2 flashed with JetPack 3.2.
But it gives me the following video signal error:

VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV
Couldn't connect to webcam.
: Invalid argument
darknet: ./src/utils.c:253: error: Assertion `0' failed.
Aborted (core dumped)

Do you have an idea what to put behind the darknet command as proper video signal?

./darknet detector demo cfg/coco.data cfg/yolo.cfg yolo.weights <video file>