Running VisionWorks nvx_sample_nvgstcamera_capture Use USB Camera LogitechC310 error

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

My Camera Information
cat /dev/v4l/by-id/*
cat: /dev/v4l/by-id/usb-046d_081b_6D1FE030-video-index0: Invalid argument

//std::string resolution = “1280x720”, input = “device:///nvcamera”;
Modify the source code to
std::string resolution = “1280x720”, input = “device:///v4l2?index=0”;

error message Can’t Open Resource

What is the reason for this?
How to solve?

2

Hi,

Suppose you should be able to find your camera on /dev/video*.
Could you help to check it first?

Thanks.

3

About whether the code of nano jetbot camera.py can modify this code to use USB camera, if you can modify it to something, I refer to this file and the modification is invalid.

https://github.com/NVIDIA-AI-IOT/jetbot/blob/master/jetbot/camera.py

def _gst_str(self):
return ‘nvarguscamerasrc ! video/x-raw(memory:NVMM), width=%d, height=%d, format=(string)NV12, framerate=(fraction)%d/1 ! nvvidconv ! video/x-raw, width=(int)%d, height=(int)%d, format=(string)BGRx ! videoconvert ! appsink’ % (self.capture_width, self.capture_height, self.fps, self.width, self.height)

Reference has tried this kind of hard to use :

nvcamerasrc fpsRange="30.0 30.0" ! video/x-raw(memory:NVMM)…

I hope to give a method to support USB camera. Thank you very much.

4

Hi,
For USB camera, you can get all supported formats through v4l2-ctl command:

nvidia@nvidia-desktop:~$ v4l2-ctl -d /dev/video1 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
        Index       : 0
        Type        : Video Capture
        Pixel Format: 'YUYV'
        Name        : YUYV 4:2:2
                Size: Discrete 640x480
                        Interval: Discrete 0.033s (30.000 fps)
                        Interval: Discrete 0.042s (24.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.100s (10.000 fps)
                        Interval: Discrete 0.133s (7.500 fps)
                        Interval: Discrete 0.200s (5.000 fps)
(...skip...)
                Size: Discrete 800x600
                        Interval: Discrete 0.042s (24.000 fps)
                        Interval: Discrete 0.050s (20.000 fps)
                        Interval: Discrete 0.067s (15.000 fps)
                        Interval: Discrete 0.100s (10.000 fps)
                        Interval: Discrete 0.133s (7.500 fps)
                        Interval: Discrete 0.200s (5.000 fps)
(...skip...)

And pick one mode(ex: 800x600p24) to run:

'v4l2src device=/dev/video1 ! video/x-raw, width=800, height=600, format=(string)YUY2, framerate=(fraction)24/1 ! videoconvert ! video/x-raw,format=BGR ! appsink'
5

I have the same error.

I try:

std::string resolution = "1280x720", input = "device:///v4l2?index=0";

desktop:~/Downloads$ v4l2-ctl --all | more
Driver Info (not using libv4l2):
	Driver name   : uvcvideo
	Card type     : HD Pro Webcam C920
	Bus info      : usb-70090000.xusb-2.4
	Driver version: 4.9.140
	Capabilities  : 0x84200001
		Video Capture
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps   : 0x04200001
		Video Capture
		Streaming
		Extended Pix Format
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
6

Hi,
For running v4l2rc,you have to modify the sample code. Please refer to
[url]visionworks-1.6-samples issue - Jetson AGX Xavier - NVIDIA Developer Forums

7

I did not understand.

In the source code I use:

std::string resolution = "1280x720", input = "device:///v4l2?index=0";

What I need change ? “device:///v4l2?index=0” is for usb cam right ?

Usb cam are in /dev/video0.

I run this line and receive this error:

gst-launch-1.0 v4l2src device="/dev/video0" ! \ "video/x-raw, width=640, height=480, format=(string)YUY2" ! \ xvimagesink -e

(gst-launch-1.0:29390): GStreamer-CRITICAL **: 10:27:46.987: gst_element_make_from_uri: assertion 'gst_uri_is_valid (uri)' failed
WARNING: erroneous pipeline: syntax error