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@keithweaver
Created May 10, 2017 19:30
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Using OpenCV takes a mp4 video and produces a number of images.
'''
Using OpenCV takes a mp4 video and produces a number of images.
Requirements
----
You require OpenCV 3.2 to be installed.
Run
----
Open the main.py and edit the path to the video. Then run:
$ python main.py
Which will produce a folder called data with the images. There will be 2000+ images for example.mp4.
'''
import cv2
import numpy as np
import os
# Playing video from file:
cap = cv2.VideoCapture('example.mp4')
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
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
@JADHAVMITHUN
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how to control rate of frame generation
this code giving more than 12000 frames for 13 sec video
plz explain me.....

@yashgorana
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@JADHAVMITHUN
You can create a variable factor=2 to save alternate frames in the loop based on the value of currentFrame.
Alternatively, you can change the value of factor such that your target FPS is maintained regardless of source video FPS.
We can get the FPS of the video by calling cap.get(cv2.CAP_PROP_FPS)

@JasOlean
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my video time length is 22 seconds, and my fps is 25 . so how to split that video into 550 frames. Because when I run your code, I got a lot of images over 550 frames. How can I do that to get 550 frames exactly?

@Arnold1
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Arnold1 commented Oct 25, 2018

@JasOlean @JADHAVMITHUN:

try:

	FPS = 25
	# Playing video from file:
	cap = cv2.VideoCapture(input)
	cap.set(cv2.CAP_PROP_FPS, FPS)
  • add if not ret: break in the loop

@Hsuthirisoe
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can we extract all the video files in a folder and save in the same folder?

@rsomani95
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@Arnold1

Adding if not ret: break in the loop did the trick to me.


On the other hand,

cap.set(cv2.CAP_PROP_FPS, FPS)

returns False for any value of FPS (I tried both an int and a float -- does it accept both?). What does this mean? Can I ignore this/ omit this piece of code entirely?

@Djotchuang
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Djotchuang commented Jun 26, 2019

I added if not ret: break in the loop and it worked for me. That is, the number of frames were fewer.

@rekhasharma-kmm
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when i run this code ,my console gives this message.
warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:901)
warning: C:\PythonProgram�ideo.mp4 (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:902)
Traceback (most recent call last):
File "GettingFrame.py", line 16, in
name='.data/frame'+str(currentFrame)+'.jpg'
NameError: name 'currentFrame' is not defined
Please rectify it.

@sajidAli110
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i want to take video of class room student when i upload video program will automatically convert video into images and match if both mach student will be tarted as present.

@DuslerOtesi
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nothing data is there inside the data folder.

@roczy
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roczy commented Apr 4, 2020

How would one snapshot photos from the video frames so that these snapshots are save every minute up until 24 hours?

@anuja1005
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I am trying same code in Pycharm-django project but I am getting following stream of errors. I am new at it so I don't know how to fix this.

Errors :
Traceback (most recent call last):
File "C:\Users\Dell\Desktop\pp\test2\venv\lib\site-packages\numpy_init_.py", line 142, in
from . import core
File "C:\Users\Dell\Desktop\pp\test2\venv\lib\site-packages\numpy\core_init_.py", line 24, in
from . import multiarray
File "C:\Users\Dell\Desktop\pp\test2\venv\lib\site-packages\numpy\core\multiarray.py", line 14, in
from . import overrides
File "C:\Users\Dell\Desktop\pp\test2\venv\lib\site-packages\numpy\core\overrides.py", line 16, in
add_docstring(
RuntimeError: implement_array_function method already has a docstring
Traceback (most recent call last):
File "C:/Users/Dell/Desktop/pp/test2/templates/ex.py", line 1, in
import cv2
File "C:\Users\Dell\Desktop\pp\test2\venv\lib\site-packages\cv2_init_.py", line 5, in
from .cv2 import *
ImportError: numpy.core.multiarray failed to import

Does anyone know how to fix this ?

@sujithgunturu
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I need break the movie at 15 frames per second. I tried the following code but it does not work. Instead it is breaking with 25 frames per second

FramesPerSecond = 15
captureTheVideo = cv2.VideoCapture('a.mp4')
captureTheVideo.set(cv2.CV_CAP_PROP_FPS, FramesPerSecond)

@927drish
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what algorithm to use to select best frame?

@aiwithshekhar
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nice, not working

@oofmaloo
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oofmaloo commented May 21, 2023

In case anyone wants to skip frames / and use youtube clips

import cv2
import numpy as np
import os
from cap_from_youtube import cap_from_youtube

# Playing video from file:
youtube_url = 'https://www.youtube.com/watch?v=6j1Oj5N7kwE'
cap = cap_from_youtube(youtube_url, 'best')

try:
    if not os.path.exists('data'):
        os.makedirs('data')
except OSError:
    print ('Error: Creating directory of data')

fps = 25
seconds_to_skip = 30
# fps * seconds_to_skip

# start frame is
currentFrame = 8500
# if you want a start frame use this, otherwise set currentFrame to 0 and comment line below
cap.set(cv2.CAP_PROP_POS_FRAMES, currentFrame)
while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()

    if ret:
        print ('Creating frame...' + str(currentFrame))
        cv2.imwrite('./data/frame{:d}.jpg'.format(currentFrame), frame)
        currentFrame += (fps * seconds_to_skip) # i.e. at 30 fps, this advances one second
        cap.set(cv2.CAP_PROP_POS_FRAMES, currentFrame)
    else:
        cap.release()
        break

# When everything done, release the capture
cv2.destroyAllWindows()

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