I want to capture frame from my camera when the specific event occurs
my code
import cv2
cap = cv2.VideoCapture("http://192.168.43.1:8080/video")
if int(data) < 45:
return_value, image = cap.read()
cv2.imwrite('Images/'+str(count)+'.png', image)
print("capture")
But its saving older frames when it capture please help i want current frame to be saved
You need to read the frames as they arrive otherwise they just buffer up. You discard the frames you don't want. The following should demonstrate this:
import cv2
cap = cv2.VideoCapture("http://192.168.43.1:8080/video")
while True:
return_value, image = cap.read()
k = cv2.waitKey(10) & 0xFF
if int(data) < 45:
cv2.imwrite('Images/'+str(count)+'.png', image)
print("capture")
if k == ord('q'):
break
Related
I am reading an rtsp(local rtsp link) stream from my cctv camera connected on LAN.
My Main Goal :-
I want to perform some processing on the frames and want to display via m3u8 in real time or nearly real time so that i can display in the frontend using hls.js.
Currently i am trying to create video in realtime so that using ffmpeg i can create the m3u8 .
Sharing my code below.
import cv2
from moviepy.editor import *
import numpy as np
import time
url = "rtsp://username:password#192.168.1.100:10554/Streaming/channels/401"
cap = cv2.VideoCapture(url)
def make_video_file(clips):
try:
print(f"clips = {clips}")
video_clip = concatenate_videoclips(clips,method='compose')
video_clip.write_videofile("video-output.mp4",fps=30)
except Exception as e:
print(e)
FRAME_COUNTER = 0
NUMBER_OF_FRAMES = 30
CLIPS = [0 for i in range(NUMBER_OF_FRAMES)]
while True:
ret, frame = cap.read()
# print(frame)
if not ret:
continue
CLIPS.pop(0)
CLIPS.append(ImageClip(frame).set_duration(1))
if FRAME_COUNTER == NUMBER_OF_FRAMES:
try:
FRAME_COUNTER = 0
make_video_file(CLIPS)
except:
pass
cv2.imshow('frame', frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
NUMBER_OF_FRAMES += 1
cap.release()
cv2.destroyAllWindows()
I'm using the below code to capture images from webcam. But i need only some no.of images to be captured on click.
# Opens the inbuilt camera of laptop to capture video.
cap = cv2.VideoCapture(0)
i = 0
while(cap.isOpened()):
ret, frame = cap.read()
# This condition prevents from infinite looping
# incase video ends.
if ret == False:
break
# Save Frame by Frame into disk using imwrite method
cv2.imwrite('Frame'+str(i)+'.jpg', frame)
i += 1
cap.release()
cv2.destroyAllWindows()```
Assuming you want 500 images add this:
...
i+=1
if (i+1)%500==0:
break
that would be easy. you can use k = cv2.waitKey(1) and check what button was pressed. here is a simple example:
import cv2
def main():
cap = cv2.VideoCapture(0)
if not cap.isOpened(): # Check if the web cam is opened correctly
print("failed to open cam")
return -1
else:
print('webcam open')
for i in range(10 ** 10):
success, cv_frame = cap.read()
if not success:
print('failed to capture frame on iter {}'.format(i))
break
cv2.imshow('click t to save image and q to finish', cv_frame)
k = cv2.waitKey(1)
if k == ord('q'):
print('q was pressed - finishing...')
break
elif k == ord('t'):
print('t was pressed - saving image {}...'.format(i))
image_path = 'Frame_{}.jpg'.format(i) # i recommend a folder and not to save locally to avoid the mess
cv2.imwrite(image_path, cv_frame)
cap.release()
cv2.destroyAllWindows()
return
if __name__ == '__main__':
main()
I'm trying to run a visual behaviour experiment where a whole heap of videos in a folder play one after another. I need to do this in python because I have a TTL pulse generator which I need to run at the start and end of each video.
I'm using cv2 and to try and play the videos but for reasons I can't figure out, I can't get them to play sequentially
Attached is my code
import cv2
import os
import random
videofolderPath = '/folderwithfiles'
videos = []
playlist = []
for file in os.listdir(videofolderPath):
if file.lower().endswith(".mp4"):
path=os.path.join('/folderwithfiles/',file)
playlist.append(path)
random.shuffle(playlist)
for i in range (3):
i += 1
cap = cv2.VideoCapture(playlist[i])
print(playlist[i])
while(True):
ret, frame = cap.read()
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q') or ret==False :
cap.release()
cv2.destroyAllWindows()
break
cv2.imshow('frame',frame)
cap.release()
cv2.destroyAllWindows()
The issue I'm having is I think they're all playing at once. When I press q I do see another video behind it but am struggling to get them to play one after another.
It looks like you have an error because you try to show the video before testing if ret == False.
Also, you should update i at the end of the loop as python indexing is zero based
The fix would look like this: (note that I changed the video folder path to test your code)
import cv2
import os
import random
videofolderPath = './videos'
videos = []
playlist = []
for file in os.listdir(videofolderPath):
if file.lower().endswith(".mp4"):
path = os.path.join(videofolderPath, file)
playlist.append(path)
random.shuffle(playlist)
for i in range(3):
cap = cv2.VideoCapture(playlist[i])
print(playlist[i])
while True:
ret, frame = cap.read()
# REMOVE cv2.imshow(f'frame_{i}', frame)
if cv2.waitKey(1) & 0xFF == ord('q') or ret == False:
cap.release()
cv2.destroyAllWindows()
break
cv2.imshow('frame', frame)
cap.release()
cv2.destroyAllWindows()
i += 1 # UPDATE INDEX AT THE END
A better way of writing your code would be something like this:
import cv2
import os
if __name__ == '__main__':
video_folder = "./videos"
for video_name in os.listdir(video_folder):
if not video_name.endswith(".mp4"):
continue
video_path = os.path.join(video_folder, video_name)
video = cv2.VideoCapture(video_path)
while True:
ret, frame = video.read()
if not ret:
break
cv2.imshow("video", frame)
cv2.waitKey(1)
video.release()
cv2.destroyAllWindows()
Also, I would recommend you to look at threading to load your video in "parallel" as it is very cpu intensive
I need a python script that live stream cam and I wanna grayscale the stream using keyboard, but I can't, every time I run the blow code stream change to grayscale but after a second it return to normal, please help me to fix this
import cv2
cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
gray=cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
c = cv2.waitKey(1)
if c & 0xFF == ord('q'):
break
elif c & 0xFF == ord('3'):
frame=gray
cv2.imshow('a',frame)
cap.release()
cv2.destroyAllWindows()
I need to change it using keyboard
Your problem is with the keyboard capture. The code waits for a keyboard input every iteration of the loop, if it gets none then none is passed to the code i.e. it doesnt remember what you typed last time so your elif is not entered the next time around.
Try the following to see what is happening...
import cv2
cap = cv2.VideoCapture(0)
gray_flag = False
while True:
ret, frame = cap.read()
gray=cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
c = cv2.waitKey(1) # only waits for 1 millisecond!!!
if c & 0xFF == ord('q'):
break
elif c & 0xFF == ord('3'):
gray_flag = True
elif c & 0xFF == ord('4'):
gray_flag = False
if gray_flag:
cv2.imshow('a', gray)
else:
cv2.imshow('a', frame)
cap.release()
cv2.destroyAllWindows()
The gray_flag ensures that your choice is remembered
Sorry I paste mirror parts at worng place, and as frame is null during mirror part, I made it into a comment while running
Looks like my cap.read() can't read anything
This is really a simple python code of opencv for just capturing a window and make webcamera work. But when I ran it, no window shown but no bugs shown either. How can I know what's wrong readily?
How can I know if the webcamera is 0 or sth else?
Why the mirror part doesn't work?
Could someone recommend me some good examples for opencv on python?
Thank you!!
import cv2
def capture_camera(mirror=True, size=None):
cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
#if mirror is True:
#frame = frame[:,::-1]
if size is not None and len(size) == 200:
frame = cv2.resize(frame, size)
cv2.imshow('camera capture', frame)
k = cv2.waitKey(100)
if k == 27:
break
cap.release()
cv2.destroyAllWindows()
capture_camera()
Your code is not executiong below if statement
if size is not None and len(size) == 200:
because size is tuple and len(size) will return 2 since you defined
size = (800,600)
2nd mistake : you were changing frame array before it is initialized.
first you need to get frame array which is returned by cap.read() then you can check if mirror is True if yes then reverse the array by frame = frame[:,::-1]
try this code :
import cv2
def capture_camera(mirror=True, size=None):
cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
if mirror is True:
frame = frame[:,::-1]
size = (800,600)
if size is not None:
frame = cv2.resize(frame, size)
cv2.imshow('camera capture', frame)
k = cv2.waitKey(100)
if k == 27:
break
cap.release()
cv2.destroyAllWindows()
capture_camera()
Try this code. It works for me:
import cv2
cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
cv2.imshow('Webcam (close with q)' ,frame)
if(cv2.waitKey(1) & 0xFF == ord('q')):
break
cap.release()
cv2.destroyAllWindows()
BTW:
Your code throws an error:
Traceback (most recent call last):
File "C:/Python/Scripts/OpenCV/Scripts/so_test.py", line 21, in <module>
capture_camera()
File "C:/Python/Scripts/OpenCV/Scripts/so_test.py", line 7, in capture_camera
frame = frame[:,::-1]
UnboundLocalError: local variable 'frame' referenced before assignment