VIDEOIO ERROR: V4L: device v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1, width=640, height=360 ! videoconvert ! appsink: Unable to query number of channels

Hi,
i installed the open data cam on an jetson nano and gets the output below. I tried it with an usb cam and one direct attached cam. I can open the video stream. What should be the reason?

Ready on http://localhost:8080
Ready on http://172.17.0.2:8080
Success init db
Process YOLO started
{ OPENDATACAM_VERSION: ‘2.1.0’,
PATH_TO_YOLO_DARKNET: ‘/darknet’,
VIDEO_INPUT: ‘usbcam’,
NEURAL_NETWORK: ‘yolov3-tiny’,
VIDEO_INPUTS_PARAMS:
{ file: ‘opendatacam_videos/demo.mp4’,
usbcam:
‘v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1, width=640, height=360 ! videoconvert ! appsink’,
usbcam_no_gstreamer: ‘-c 0’,
experimental_raspberrycam_docker:
‘v4l2src device=/dev/video2 ! video/x-raw, framerate=30/1, width=640, height=360 ! videoconvert ! appsink’,
raspberrycam_no_docker:
‘nvarguscamerasrc ! video/x-raw(memory:NVMM),width=1280, height=720, framerate=30/1, format=NV12 ! nvvidconv ! video/x-raw, format=BGRx, width=640, height=360 ! videoconvert ! video/x-raw, format=BGR ! appsink’,
remote_cam:
‘YOUR IP CAM STREAM (can be .m3u8, MJPEG …), anything supported by opencv’ },
VALID_CLASSES: [ ‘*’ ],
DISPLAY_CLASSES:
[ { class: ‘bicycle’, icon: ‘1F6B2.svg’ },
{ class: ‘person’, icon: ‘1F6B6.svg’ },
{ class: ‘truck’, icon: ‘1F69B.svg’ },
{ class: ‘motorbike’, icon: ‘1F6F5.svg’ },
{ class: ‘car’, icon: ‘1F697.svg’ },
{ class: ‘bus’, icon: ‘1F68C.svg’ } ],
PATHFINDER_COLORS:
[ ‘#1f77b4’,
#ff7f0e’,
#2ca02c’,
#d62728’,
#9467bd’,
#8c564b’,
#e377c2’,
#7f7f7f’,
#bcbd22’,
#17becf’ ],
COUNTER_COLORS:
{ yellow: ‘#FFE700’,
turquoise: ‘#A3FFF4’,
green: ‘#a0f17f’,
purple: ‘#d070f0’,
red: ‘#AB4435’ },
NEURAL_NETWORK_PARAMS:
{ yolov3:
{ data: ‘cfg/coco.data’,
cfg: ‘cfg/yolov3.cfg’,
weights: ‘yolov3.weights’ },
‘yolov3-tiny’:
{ data: ‘cfg/coco.data’,
cfg: ‘cfg/yolov3-tiny.cfg’,
weights: ‘yolov3-tiny.weights’ },
‘yolov2-voc’:
{ data: ‘cfg/voc.data’,
cfg: ‘cfg/yolo-voc.cfg’,
weights: ‘yolo-voc.weights’ } },
TRACKER_ACCURACY_DISPLAY:
{ nbFrameBuffer: 300,
settings:
{ radius: 3.1,
blur: 6.2,
step: 0.1,
gradient: [Object],
canvasResolutionFactor: 0.1 } },
MONGODB_URL: ‘mongodb://127.0.0.1:27017’ }
layer filters size input output
0 (node:51) [DEP0001] DeprecationWarning: OutgoingMessage.flush is deprecated. Use flushHeaders instead.
conv 16 3 x 3 / 1 416 x 416 x 3 -> 416 x 416 x 16 0.150 BF
1 max 2 x 2 / 2 416 x 416 x 16 -> 208 x 208 x 16 0.003 BF
2 conv 32 3 x 3 / 1 208 x 208 x 16 -> 208 x 208 x 32 0.399 BF
3 max 2 x 2 / 2 208 x 208 x 32 -> 104 x 104 x 32 0.001 BF
4 conv 64 3 x 3 / 1 104 x 104 x 32 -> 104 x 104 x 64 0.399 BF
5 max 2 x 2 / 2 104 x 104 x 64 -> 52 x 52 x 64 0.001 BF
6 conv 128 3 x 3 / 1 52 x 52 x 64 -> 52 x 52 x 128 0.399 BF
7 max 2 x 2 / 2 52 x 52 x 128 -> 26 x 26 x 128 0.000 BF
8 conv 256 3 x 3 / 1 26 x 26 x 128 -> 26 x 26 x 256 0.399 BF
9 max 2 x 2 / 2 26 x 26 x 256 -> 13 x 13 x 256 0.000 BF
10 conv 512 3 x 3 / 1 13 x 13 x 256 -> 13 x 13 x 512 0.399 BF
11 max 2 x 2 / 1 13 x 13 x 512 -> 13 x 13 x 512 0.000 BF
12 conv 1024 3 x 3 / 1 13 x 13 x 512 -> 13 x 13 x1024 1.595 BF
13 conv 256 1 x 1 / 1 13 x 13 x1024 -> 13 x 13 x 256 0.089 BF
14 conv 512 3 x 3 / 1 13 x 13 x 256 -> 13 x 13 x 512 0.399 BF
15 conv 255 1 x 1 / 1 13 x 13 x 512 -> 13 x 13 x 255 0.044 BF
16 yolo
[yolo] params: iou loss: mse, iou_norm: 0.75, cls_norm: 1.00, scale_x_y: 1.00
17 route 13
18 conv 128 1 x 1 / 1 13 x 13 x 256 -> 13 x 13 x 128 0.011 BF
19 upsample 2x 13 x 13 x 128 -> 26 x 26 x 128
20 route 19 8
21 conv 256 3 x 3 / 1 26 x 26 x 384 -> 26 x 26 x 256 1.196 BF
22 conv 255 1 x 1 / 1 26 x 26 x 256 -> 26 x 26 x 255 0.088 BF
23 yolo
[yolo] params: iou loss: mse, iou_norm: 0.75, cls_norm: 1.00, scale_x_y: 1.00
Total BFLOPS 5.571
Allocate additional workspace_size = 52.43 MB
Loading weights from yolov3-tiny.weights…Demo
Done!

(darknet:64): GStreamer-CRITICAL **: 16:30:08.644: gst_element_get_state: assertion ‘GST_IS_ELEMENT (element)’ failed
VIDEOIO ERROR: V4L: device v4l2src device=/dev/video0 ! video/x-raw, framerate=30/1, width=640, height=360 ! videoconvert ! appsink: Unable to query number of channels

Hi,
Please try Honey_Patouceul’s suggestion.
https://devtalk.nvidia.com/default/topic/1066411/jetson-tx2/videoio-error-unable-to-query-number-of-channels-/post/5401507/#5401507