Segmentation fault while running examples with USB camera

Autonomous Machines Jetson & Embedded Systems Jetson Nano
#1

I am trying to run ./detectnet-camera --camera /dev/video0 and camera-viewer /dev/video0 examples and running into a segmentation fault. I do have a screenshot of the log, but I am not sure how to post it in this topic. The log is very similar to what is mentioned in this thread:
https://devtalk.nvidia.com/default/topic/1057554/jetson-nano/imagenet-camera-on-my-logitech-hd-webcam-270-crashed-with-segmentation-fault-core-dumped-/

and the difference is that I have already tried providing the camera input as /dev/video0 which is the correct video source.

Another difference in the log is:

[gStreamer] opening gstCamera for streaming, transitioning pipeline to GST_STAT_PLAYING

The other statements in log are similar to the one shown in the link. It ends as follows:

camera-viewer: camera open for streaming
GST_ARGUS: Creating output stream
CONSUMER:Waiting until producer is connected …
GST_ARGUS: Available sensor modes:
Segmentation fault (core-dumped)

Kindly suggest if any other debugging steps are required.

#2

Hi,
The error shows it opens the source as Argus camera source. Your source is USB camera and you should specify it as v4l2 source in command line.

#3

How do I specify it as a v4l2 source. This is the way I have already tried out:

./detectnet-camera --camera /dev/video0

#4

I am using Logitech C170. Is it because this model is unsupported?

#5

Hi,
https://github.com/dusty-nv/jetson-inference/blob/master/docs/detectnet-camera.md
The example is

$ ./detectnet-camera <b>--camera=/dev/video0</b>

You probably miss ‘=’.

#6

That was a typo when I posted it. I have tried the same command as you have posted.

Now when I run this command, I notice that jetson freezes. Following is the log towards the end:

[gstreamer] gstreamer changed state from PAUSED to PLAYING ==> v4l2src0
[gstreamer] gstreamer msg stream start ==> pipeline0
[gstreamer] gstCamera onEOS
[gstreamer] gstreamer v4l2src0 ERROR Internal data stream error.
[gstreamer] gstreamer Debugging info:gstbasesrc.c(3055):gst_base_src_loop ():
/GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
streaming stopped, reason not negotiated (-4)
[gstreamer] gstreamer changed state from READY to PAUSED ==>mysink
detectnet-camera: camera open for streaming

After this the terminal is stuck and I have to kill the process

#7

Inow tried with Logitech C920 camera which is mentioned in the list of supported cameras and it is working

#8

Hi,
Please check if you can launch C170 by following the steps:
https://devtalk.nvidia.com/default/topic/1057681/jetson-tx1/logitech-c930e-on-jetson-tx1-very-slow-and-choppy-video/post/5363417/#5363417

https://github.com/dusty-nv/jetson-utils/blob/798c416c175d509571859c9290257bd5cce1fd63/camera/gstCamera.cpp
The pipeline of launching USB camera(v4l2src) is

{
		ss << "v4l2src device=" << mCameraStr << " ! ";
		ss << "video/x-raw, width=(int)" << mWidth << ", height=(int)" << mHeight << ", "; 
		
	#if NV_TENSORRT_MAJOR >= 5
		ss << "format=YUY2 ! videoconvert ! video/x-raw, format=RGB ! videoconvert !";
	#else
		ss << "format=RGB ! videoconvert ! video/x-raw, format=RGB ! videoconvert !";
	#endif

		ss << "appsink name=mysink";

		mSource = GST_SOURCE_V4L2;
	}

For C170, probably the pipeline have to be customized. You may try to modify format, width, height and check again.