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()
Related
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()
I am trying to save a video using open CV, the idea is to alternate the video frames from colored to gray scale for few seconds. When I do the saving, the video saves the colored frames only.
import cv2
def saving(cap):
width=cap.get(cv2.CAP_PROP_FRAME_WIDTH)
height=cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
fps= cap.get(cv2.CAP_PROP_FPS)
fourcc=cv2.VideoWriter_fourcc(*'XVID')
out=cv2.VideoWriter('Project11.mp4',fourcc,fps,(int(width),int(height)))
return (out)
def first4seconds(video):
c=saving(video)
while(video.isOpened()):
print(video.get(cv2.CAP_PROP_POS_MSEC))
ret, frame = video.read()
if ret==True:
if cv2.waitKey(25) & 0xFF == ord('q'):
break
else:
break
if(500<=int(video.get(cv2.CAP_PROP_POS_MSEC))<1000 or 2000<=int(video.get(cv2.CAP_PROP_POS_MSEC))<3000):
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
c.write(gray)
cv2.imshow('frame',gray)
else:
c.write(frame)
cv2.imshow('frame',frame)
video.release()
cv2.destroyAllWindows()
cap = cv2.VideoCapture('test.mp4')
first4seconds(cap)
if(500<=int(video.get(cv2.CAP_PROP_POS_MSEC))<1000 or 2000<=int(video.get(cv2.CAP_PROP_POS_MSEC))<3000):
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
**gray_2=cv2.cvtColor(gray,cv2.COLOR_GRAY2BGR)**
**cv2.imshow('frame',gray_2)**
**c.write(gray_2)**
else:
c.write(frame)
cv2.imshow('frame',frame)
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.
This code opens the video but it plays in slow-motion.
How can I fix this so the video can play normal speed?
import numpy as np
import cv2
cap = cv2.VideoCapture('Predicacion.mp4')
while(cap.isOpened()):
ret, frame = cap.read()
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
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.