I am able to extract the frames of a certain test.mp4 file using the following code:
import cv2
def get_frames():
cap = cv2.VideoCapture('test.mp4')
i = 0
while cap.isOpened():
ret, frame = cap.read()
if not ret:
break
cv2.imwrite('test_'+str(i)+'.jpg', frame)
i += 1
cap.release()
cv2.destroyAllWindows()
A lot of the frames that are extracted are useless (they're nearly identical). I need to be able to set a certain rate at which the frame extraction can be done.
I think you need to just skip frames based on a fixed cycle.
import cv2
def get_frames():
cap = cv2.VideoCapture('test.mp4')
i = 0
# a variable to set how many frames you want to skip
frame_skip = 10
# a variable to keep track of the frame to be saved
frame_count = 0
while cap.isOpened():
ret, frame = cap.read()
if not ret:
break
if i > frame_skip - 1:
frame_count += 1
cv2.imwrite('test_'+str(frame_count*frame_skip)+'.jpg', frame)
i = 0
continue
i += 1
cap.release()
cv2.destroyAllWindows()
Try below logic. Here, we are waiting for a period of time(based on frame rate) and reading the last frame.
def get_frames():
cap = cv2.VideoCapture('test.mp4')
frame_rate = 10
prev = 0
i = 0
while cap.isOpened():
time_elapsed = time.time() - prev
ret, frame = cap.read()
if not ret:
break
if time_elapsed > 1./frame_rate:
# print(time_elapsed)
prev = time.time()
cv2.imwrite('./data/sample1/test_'+str(i)+'.jpg', frame)
i += 1
cap.release()
cv2.destroyAllWindows()
As an alternative to writing your own code to do this, have you considered using FFMPEG? FFMPEG has the ability to extract all frames from a video and save them as images, it also can extract frames at a lower frame rate than the source video.
See here for a demonstration of what I think you're trying to do, and the arguments to give ffmpeg to do so.
Related
I want to capture image and store it on my local system after every n seconds, I can not set frame(5) as I want video and detection to run completely. Currently my code is capturing image whenever a condition is failed.
def create_alert(self):
count = 0
cap = cv2.VideoCapture(0)
while cap.isOpened():
r,f = cap.read()
try:
info = ppe.detection(f)
x,y,w,h,label,conf = info[0]
if label == "lineman_fail":
# engine.say("Warning")
# engine.runAndWait()
ppe.take_screenshot(f,count)
count+=1
print(count)
print("Something wrong")
# cv2.imwrite("img_"+str(count)+".jpg",f)
except Exception as e:
print("_______-",e)
cv2.imshow("image",f)
if cv2.waitKey(1) & 0xFF == ord("q") :
break
cap.release()
cv2.destroyAllWindows()
def take_screenshot(self,frame,count):
prev = time.time()
cv2.imwrite("screen_shot/img_"+str(count)+".jpg",frame)
In order to capture image every n seconds try using datetime library, and find the difference between current time and elapsed time. Then use cv2's imwrite
while True:
current = time()
yolo_v4.delta += current - previous
previous = current
frame = camera.get_frame()
if yolo_v4.delta > 10:
ct=datetime.datetime.now().strftime("%Y_%m_%d_%H_%M_%S")
cv2.imwrite("screen_shot/img_"+str(ct)+".jpg",frame)
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 want to break my video into frames.
I am using the following code:
import cv2
import numpy as np
import os
# Playing video from file:
cap = cv2.VideoCapture('myvideo.mp4')
cap.set(cv2.CAP_PROP_FPS, 5)
try:
if not os.path.exists('data'):
os.makedirs('data')
except OSError:
print ('Error: Creating directory of data')
currentFrame = 0
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# Saves image of the current frame in jpg file
name = './data/frame' + str(currentFrame) + '.jpg'
print ('Creating...' + name)
cv2.imwrite(name, frame)
# To stop duplicate images
currentFrame += 1
if not ret: break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
I have set the FPS = 5 and 'myvideo.mp4' is 0:55 sec long. So, I'd expect to have 55*5 = 275 frames, but the code above gives me a lot more frames and it doesn't stop generating frames. Is something wrong in the code?
if you want a proper framerate you can do
framerate = vid.get(5)
instead of
cap.set(cv2.CAP_PROP_FPS, 5)
this will give you the exact framerate
I have a RaspberryPi, a few IP camera's and I would like to get a fresh image from all these camera's every 5 minutes. I have the following script, which open the RTSP feed af grabs images ALL THE TIME, talking 10-25 every second it runs.
Is there a way to open the videofeed an take only 1 image?
import cv2
import time
cap = cv2.VideoCapture('rtsp://192.168.86.81:554/11') # it can be rtsp or http $
ret, frame = cap.read()
while ret:
cv2.imwrite('images/{}.jpg'.format(time.time()), frame)
ret, frame = cap.read()
This solved my problem. I removed time as I do not need this. I will let the aboce code stand in case anybody would want to play around with this
import cv2
cap = cv2.VideoCapture('rtsp://192.168.86.81:554/11') # it can be rtsp or http stream
ret, frame = cap.read()
if cap.isOpened():
_,frame = cap.read()
cap.release() #releasing camera immediately after capturing picture
if _ and frame is not None:
cv2.imwrite('images/latest.jpg', frame)
import cv2
import time
from datetime import datetime
import getpass
#imagesFolder = "C:/Users/<user>/documents"
# https://stackoverflow.com/questions/842059/is-there-a-portable-way-to-get-the-current-username-in-python
imagesFolder = "C:/Users/" + getpass.getuser() + "/documents"
#cap = cv2.VideoCapture("rtsp://192.168.86.81:554/11")
# Use public RTSP Streaming for testing, but I am getting black frames!
cap = cv2.VideoCapture("rtsp://192.168.86.81:554/11")
frameRate = cap.get(5) #frame rate
count = 0
while cap.isOpened():
start_time = time.time()
frameId = cap.get(1) # current frame number
ret, frame = cap.read()
if (ret != True):
break
filename = imagesFolder + "/image_" + str(datetime.now().strftime("%d-%m-%Y_%I-%M-%S_%p")) + ".jpg"
cv2.imwrite(filename, frame)
# Show frame for testing
cv2.imshow('frame', frame)
cv2.waitKey(1)
count += 1
#Break loop after 5*60 minus
if count > 5*60:
break
elapsed_time = time.time() - start_time
# Wait for 60 seconds (subtract elapsed_time in order to be accurate).
time.sleep(60 - elapsed_time)
cap.release()
print ("Done!")
cv2.destroyAllWindows()