OpenCV2 Write to webcam python - python

Can I do something like this?
import cv2
cap = cv2.VideoCapture(0)
wri = cv2.device(0)
while 1:
ret, val = cv2.cvtColor(cap.read(), cv2.RGB2GRAY)
if ret:
wri.setCurrentFrame(val)
if cv2.WaitKey(0) == 27:
break
cap.release()
wri.release()
cv2.destroyAllWindows()
I want to make something like ManyCam.
I have researched and have not been able to find anything like this.

Note that the VideoCapture object is strictly responsible for capturing(read) an image from the stream(webcam, video file, RTSP, e.t.c.).
Then you can do any further processing with any of the opencv functions
Now, the webcam hardware is a device you read from, not write to.

Try of this way
import cv2
capture = cv2.VideoCapture(0)
while(True):
ret, frame = capture.read()
grayFrame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('video gray', grayFrame)
cv2.imshow('video original', frame)
if cv2.waitKey(1) == 27:
break
capture.release()
cv2.destroyAllWindows()
That's it

Related

Facecam Video does not open with cv2.VideoCapture() and cannot be read

I'm new to OpenCV and just started learning
I am using macOS, python version 3.8.1
My code:
import cv2
# takes facecam video
cap = cv2.VideoCapture(-1)
while True:
# Capture frame-by-frame
ret, frame = cap.read()
if cap.isOpened() == True:
# Our operations on the frame come here
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
cap.open(-1)
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
This works for me
import cv2
cap = cv2.VideoCapture(0)
while True:
ne, frame = cap.read()
cv2.imshow("Webcam Capture", frame)
if cv2.waitKey(1) & 0xFF == ord("A"):
break
cap.release()
cv2.destroyAllWindows()

Why isn't the video feed read by the web camera in python code?

When I run my python opencv code, the web camera does not read a video feed. There are no any errors, but the black color output with wifi sign and loading sign i there. How to fix that and read the video feed. Here is my code and the output.
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))
print(cap.isOpened())
while(cap.isOpened()):
ret, frame = cap.read()
if ret == True:
print(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
print(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
out.write(frame)
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame', gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
If you are only using one camera you can try the following:
cap = cv2.VideoCapture(-1)
This will pick up the first webcam the system can find.
How are you overlaying the wifi/loading signs - I assume they are not part of the webcam feed?

cxFreeze issues with OpenCV - video doesn't play

When I use cx_Frezze to create an exe for the below OpenCV code it works as expected:
import cv2
import numpy as np
# mouse callback function
def draw_circle(event,x,y,flags,param):
if event == cv2.EVENT_LBUTTONDBLCLK:
cv2.circle(img,(x,y),100,(255,50,70),-1)
# Create a black image, a window and bind the function to window
img = np.zeros((512,512,3), np.uint8)
cv2.namedWindow('image')
cv2.setMouseCallback('image',draw_circle)
while(1):
cv2.imshow('image',img)
if cv2.waitKey(20) & 0xFF == 27:
break
cv2.destroyAllWindows()
But, when I try to do the same thing with the simple code below, the video is not displayed. Basically, nothing happens. No error message, no crash... nothing. But, no video.
import numpy as np
import cv2
try:
cap = cv2.VideoCapture('some_video.wmv')
while(cap.isOpened()):
ret, frame = cap.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame', gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
except:
pass
The setup.py code is the same for both, except for the file name.
Add print statements to your code for debugging:
import numpy as np
import cv2
try:
cap = cv2.VideoCapture('some_video.wmv')
if not cap.isOpened():
print('VideoCapture not opened')
exit(1)
while True:
ret, frame = cap.read()
if not ret:
print('frame is empty')
break
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame', gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
except:
pass
If VideoCapture is not opened or frame is empty then check this answer.

Issue at opening a video with VideoCapture

I'm unable to open some avi files with Videocapture from opencv. In fact, I just have one video which works, but none of my other videos will open.
The code I use:
import numpy as np
import cv2
cap = cv2.VideoCapture('test.avi')
while True:
ret, frame = cap.read()
if ret == True:
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame',gray)
if cv2.waitKey(30) & 0xFF == ord('q'):
break
else:
break
cap.release()
cv2.destroyAllWindows()

Stream video from drone Parrot 2.0. Python + cv2

I am trying to have access to the stream of my drone's camera.
Here my code:
import cv2
import numpy
import libardrone
drone = libardrone.ARDrone()
cap = drone.image
while(True):
cap = drone.image
if not cap:
continue
ret, frame = convert
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
It does not work. It does not open any frame where I can see the stream video of my drone's camera.
What's wrong? Do you have any suggestions?
Thank you!
import cv2
cam = cv2.VideoCapture('tcp://192.168.1.1:5555')
running = True
while running:
# get current frame of video
running, frame = cam.read()
if running:
cv2.imshow('frame', frame)
if cv2.waitKey(1) & 0xFF == 27:
# escape key pressed
running = False
else:
# error reading frame
print 'error reading video feed'
cam.release()
cv2.destroyAllWindows()
Try this code...This works for me.

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