Stream image with gstreamer and python over tcp

[abolfazl_asari]

hi I’m trying to stream the camera feed of the jetson nano camera from Jetson to another Linux system with gstreamer over TCP
I can take frames from Jetson and show them with autovideosink element in the terminal with this pipeline:
gst-launch-1.0 tcpclientsrc host=10.42.0.118 port=5000 ! gdpdepay ! rtph264depay ! avdec_h264 max-threads=1 ! videoconvert ! fpsdisplaysink sync=false
and it’s working pretty good
but when I try to run this pipeline in python with appsink it doesn’t work at all and i can’t see the images
I’m running this script :
import cv2

cap = cv2.VideoCapture(‘tcpclientsrc host=10.42.0.118 port=5000 ! gdpdepay ! rtph264depay ! h264parse ! avdec_h264 ! videoconvert ! “video/x-raw,format=(string)BGR” ! videoconvert ! appsink sync=false’, cv2.CAP_GSTREAMER)

if not cap.isOpened():
print(“Failed to open video stream”)
exit()

while True:
ret, frame = cap.read()
if not ret:
break

cv2.imshow('Frame', frame)

if cv2.waitKey(1) & 0xFF == ord('q'):
    break

cap.release()
cv2.destroyAllWindows()
and i get this message
‘Failed to open video stream’
can anybody help me to do this ?
thank you all

[DaneLLL]

Hi,
The pipeline may not be well read due to " " or ' '. There are working samples:
Doesn't work nvv4l2decoder for decoding RTSP in gstreamer + opencv - #3 by DaneLLL
Displaying to the screen with OpenCV and GStreamer - #9 by DaneLLL

You may put the pipeline in " " for a try:

"tcpclientsrc host=10.42.0.118 port=5000 ! gdpdepay ! rtph264depay ! h264parse ! avdec_h264 ! videoconvert ! video/x-raw,format=BGR ! videoconvert ! appsink sync=false"

[abolfazl_asari]

no i tried this befor it dosent work

[Honey_Patouceul]

I’m not positive about using RTP repayed into GDP for TCP. I’d advise to use mkv such as this as sender:

# Video test case
gst-launch-1.0 videotestsrc ! queue ! nvvidconv ! nvv4l2h264enc insert-vui=1 insert-sps-pps=1 idrinterval=15 ! h264parse ! matroskamux streamable=1 ! tcpserversink host=<Jeston_IP> port=4953

# CSI camera with argus
gst-launch-1.0 nvarguscamerasrc ! nvvidconv ! nvv4l2h264enc insert-vui=1 insert-sps-pps=1 idrinterval=15 ! h264parse ! matroskamux streamable=1 ! queue ! tcpserversink host=<Jeston_IP> port=4953

Then on client:

gst-launch-1.0 tcpclientsrc host=<Jetson_IP> port=4953 ! queue ! matroskademux ! h264parse ! avdec_h264 ! queue ! videoconvert ! fpsdisplaysink text-overlay=0 video-sink=fakesink -v

where <Jetson_IP> is the IP address of the Jetson.
If this works, try the following python code :

import cv2

# Check for gstreamer support from opencv
import re
print('GStreamer support: %s' % re.search(r'GStreamer\:\s+(.*)', cv2.getBuildInformation()).group(1))


# Create capture (you would edit for setting your Jetson's IP)
cap = cv2.VideoCapture('tcpclientsrc host=<Jetson_IP> port=4953 ! queue ! matroskademux ! h264parse ! avdec_h264 ! queue ! videoconvert ! video/x-raw,format=BGR ! queue ! appsink drop=1', cv2.CAP_GSTREAMER)
if not cap.isOpened():
	print('Failed to open camera');
	exit(-1)
w = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
h = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
fps = cap.get(cv2.CAP_PROP_FPS)
print('camera opened, framing %dx%d@%f fps' % (w,h,fps))

# Loop reading frame and displaying	
while True:
	ret,frame = cap.read()
	if not ret:
		print('Failed to read from camera')
		cap.release()
		exit(-3)
	cv2.imshow('Test', frame)
	cv2.waitKey(1)
cap.release()