Rtsp and gst-launch is not working opencv.VideoCapture in python but working in x86

Robotics & Edge Computing Jetson & Embedded Systems Jetson Xavier NX
1

I am using python 3.6.9 and opencv 4.5.2.

In x86, below code is working. I could see video, but it is not working in xavier nx.

import cv2

cameraCapture = cv2.VideoCapture(“rtsp://192.168.0.201:554/live0”, cv2.CAP_GSTREAMER)

if not cameraCapture.isOpened():
print(‘VideoCapture not opened’)
exit(-1)
cv2.namedWindow(‘RTSP Receiver’)

print(‘VideoCapture is capturing…’)
while True:
success, frame = cameraCapture.read()
cv2.imshow(‘RTSP Receiver’, frame)

if cv2.waitKey(1) & 0xff == ord("q"):
	break

cv2.destroyWindow(‘RTSP Receiver’)

cameraCapture.release()

.

Additionally, gst-launch is working in shell command like below but not working using opencv.

gst-launch-1.0 rtspsrc location=rtsp://192.168.0.201:554/live0 drop_on_latency=true udp_buffer_size=1572864 do_retransmission=false latency=1 ! queue max_size_time=5000000000 max-size-bytes=0 max-size-buffers=0 leaky=1 ! rtph265depay ! h265parse ! omxh265dec ! nvoverlaysink

import cv2

gst_str = ‘rtspsrc location=rtsp://192.168.0.201:554/live0 drop_on_latency=true udp_buffer_size=1572864 do_retransmission=false latency=1 ! queue max_size_time=5000000000 max-size-bytes=0 max-size-buffers=0 leaky=1 ! rtph265depay ! h265parse ! omxh265dec ! nvoverlaysink’

cameraCapture = cv2.VideoCapture(gst_str, cv2.CAP_GSTREAMER)

if not cameraCapture.isOpened():
print(‘VideoCapture not opened’)
exit(-1)
cv2.namedWindow(‘RTSP Receiver’)

print(‘VideoCapture is capturing…’)
while True:
success, frame = cameraCapture.read()
cv2.imshow(‘RTSP Receiver’, frame)

if cv2.waitKey(1) & 0xff == ord("q"):
	break

cv2.destroyWindow(‘RTSP Receiver’)

cameraCapture.release()

Thanks,

3

Hi,
Please try this python code on Xavier NX:
Doesn't work nvv4l2decoder for decoding RTSP in gstreamer + opencv - #3 by DaneLLL

4

It works well great!. But streaming is delayed about 5~6 sec.
What option needs?

Thank you.

5

Hi,
Generally delay is from the source and network, but you can run system in max performance mode and check if there is improvment. You can execute sudp nvpmodel -m 2, sudo jetson_clocks, and in nvv4l2decoder, set

  enable-max-performance: Set to enable max performance
                        flags: readable, writable
                        Boolean. Default: false

You may also set

  disable-dpb         : Set to disable DPB buffer for low latency
                        flags: readable, writable
                        Boolean. Default: false

But this works with certain h264 stream. You may try with your source and see if it works.

6

how to set in nvv4l2decoder?

7

Hi,
You may try

... ! nvv4l2decoder enable-max-performance-1 ! ...

and

... ! nvv4l2decoder enable-max-performance-1 disable-dpb=1 ! ...
8

Hi,

this code is working. I think the delay is enough to accept.

import cv2

gst_str = “rtspsrc location=rtsp://192.168.0.201:554/live0 drop_on_latency=true latency=1 ! rtph265depay ! h265parse ! nvv4l2decoder ! nvvidconv ! video/x-raw, format=(string)BGRx ! videoconvert ! video/x-raw,format=BGR ! appsink”

cameraCapture = cv2.VideoCapture(gst_str, cv2.CAP_GSTREAMER)

if not cameraCapture.isOpened():
print(‘VideoCapture not opened’)
exit(-1)
cv2.namedWindow(‘RTSP Receiver’)

print(‘VideoCapture is capturing…’)
while True:
success, frame = cameraCapture.read()
cv2.imshow(‘RTSP Receiver’, frame)

if cv2.waitKey(1) & 0xff == ord("q"):
    break

cv2.destroyWindow(‘RTSP Receiver’)

cameraCapture.release()

but the video is crumble shortly when fast scene changes and etc.