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
Related
I'm using OpenCV and RTSP source to continuously record video from the RTSP source for 1 minutes.
And then start the process again and create new one.
Recording works fine for a while and then the program would only create files that are 6kb in size that are not playable.
import numpy as np
import cv2
import time
def get_output(out=None):
#Specify the path and name of the video file as well as the encoding, fps and resolution
if out:
out.release()
return cv2.VideoWriter(str(time.strftime('%d %m %Y - %H %M %S' )) + '.avi', cv2.VideoWriter_fourcc(*'MJPG'),
24, (320,240))
cap = cv2.VideoCapture("rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mp4")
next_time = time.time() + 60
out = get_output()
while True:
if time.time() > next_time:
next_time += 60
out = get_output(out)
# Capture frame-by-frame
ret, frame = cap.read()
if ret:
out.write(frame)
cv2.imshow('Frame', frame)
# Break the loop
else:
break
cap.release()
cv2.destroyAllWindows()
I have following code which reads frames from video file and stores as jpg. The code works fine if I read frames from camera directly but for video file it doesn't read the frames.
cap = cv2.VideoCapture('C:/Users/lostpanda.mp4')
#cap = cv2.VideoCapture(0)
count = 0
while cap.isOpened():
ret,frame = cap.read()
print(ret,frame)
cv2.imshow('window-name', frame)
name = 'C:/Users/video_testing/video-frames/' + str(count) + '.jpg'
#cv2.imwrite("frame%d.jpg" % count, frame)
cv2.imwrite(name,frame)
count = count + 1
if cv2.waitKey(10) & 0xFF == ord('q'):
break
Thanks
You can try this instead:
import cv2
import os
# Read the video from specified path
cam =cv2.VideoCapture(r"C:/Users/lostpanda.mp4")
try:
# creating a folder named data
if not os.path.exists('video-frames'):
os.makedirs('video-frames')
# if not created then raise error
except OSError:
print ('Error: Creating directory of data')
# frame
currentframe = 0
while(True):
# reading from frame
ret,frame = cam.read()
if ret:
# if video remains continue creating images
name = './video-frames/frame' + str(currentframe)+ '.jpg'
print ('Creating...' + name)
# write extracted images
cv2.imwrite(name, frame)
#Counter to show number of frames that are being created
currentframe += 1
else:
break
# Release all space and windows once done
cam.release()
cv2.destroyAllWindows()
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.
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()
I'm using OpenCV and Python to take images. However currently I can only take one picture at a time. I would like to have OpenCV to take multiple pictures. This is my current code.
import cv2.cv as cv
import time
cv.NamedWindow("camera", 1)
capture = cv.CaptureFromCAM(0)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("camera", img)
cv.SaveImage('pic.jpg', img)
if cv.WaitKey(10) == 27:
break
Your code overwrite a file. Save to different file each time.
For example:
import cv2.cv as cv
import time
cv.NamedWindow("camera", 1)
capture = cv.CaptureFromCAM(0)
i = 0
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("camera", img)
cv.SaveImage('pic{:>05}.jpg'.format(i), img)
if cv.WaitKey(10) == 27:
break
i += 1
A minimal example of what you'd like to do, based on the c++ binded interface.
import cv2
cpt = 0
maxFrames = 5 # if you want 5 frames only.
try:
vidStream = cv2.VideoCapture(0) # index of your camera
except:
print "problem opening input stream"
sys.exit(1)
while cpt < maxFrames:
ret, frame = vidStream.read() # read frame and return code.
if not ret: # if return code is bad, abort.
sys.exit(0)
cv2.imshow("test window", frame) # show image in window
cv2.imwrite("image%04i.jpg" %cpt, frame)
cpt += 1
A full example of script, able to read from a camera index, or a file. Includes some failsafes and some information about read device.
usage: record.py [source] [target folder]
#!/usr/bin/env python
import cv2
import sys
import os
cpt = 0
maxFrames = 30
try:
targetDir = sys.argv[2]
except:
targetDir = "" # if no argument, then use current directory
try: # read input. eval if to transform video index to int
vidStream = cv2.VideoCapture(eval(sys.argv[1]))
except:
print "problem opening input stream"
sys.exit(1)
if not vidStream.isOpened():
print "capture stream not open"
sys.exit(1)
# informations in case the input is a video file.
nFrames = vidStream.get(cv2.cv.CV_CAP_PROP_FRAME_COUNT)
print "frame number: %s" %nFrames
fps = vidStream.get(cv2.cv.CV_CAP_PROP_FPS)
print "FPS value: %s" %fps
# note that we could use frame number here, or "while 1"
# so we could read from a live written file or capture devide.
while cpt < maxFrames:
ret, frame = vidStream.read() # read frame and return code.
if not ret:
print "end of stream"
sys.exit(0)
cv2.imshow("test window", frame) # show image in window
cv2.imwrite(os.path.join(targetDir, "image_%04i.jpg" %cpt), frame)
cpt += 1
keyPressed = cv2.waitKey(1) # time to wait between frames
if keyPressed != -1: # if user pressed a key, stop recording.
sys.exit(0)
change the name of the image to be saved to " [image name] [a number which increase after every loop] "
By doing this your image will be stored with a new name after every loop.. otherwise all the images will overwrite the same name !
import cv2.cv as cv
import time
cv.NamedWindow("camera", 1)
capture = cv.CaptureFromCAM(0)
num = 0
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("camera", img)
cv.SaveImage('pic'+str(num)+'.jpg', img)
if cv.WaitKey(10) == 27:
break
num += 1
now your images will be saved as pic0.jpg, pic1.jpg, pic2.jpg and so on..
i think this wil helpful...
import cv2
vid = cv2.VideoCapture("video.mp4")
d = 0
ret, frame = vid.read()
while ret:
ret, frame = vid.read()
filename = "images/file_%d.jpg"%d
cv2.imwrite(filename, frame)
d+=1
this will save every frame with different name.