OpenCV - Video doesn't play after saving in Python - python

I tried to save a video after it changes resolution to 300x300 on Python, but my video can't play after saving with
0xc10100be error: "This file isn't playable. That might be because the file type is unsupported, the file extension is incorrect, or the file is corrupt."
Here is my program:
import numpy as np
import cv2
cap = cv2.VideoCapture("F:\\mi\\Camera\\2b7d9eccaddffffe3c9ba70b7fe6c12e(0).mp4")
cv2.namedWindow("vid1", 0)
cv2.resizeWindow("vid1", 300,300)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (300,300))
while(cap.isOpened()):
ret, frame = cap.read()
cv2.imshow('vid1',frame)
out.write(frame)
if cv2.waitKey(25) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
What is wrong?

after asking my teacher about this problem, He fixed my program:
import numpy as np
import cv2
cap = cv2.VideoCapture("F:\\mi\\Camera\\2b7d9eccaddffffe3c9ba70b7fe6c12e(0).mp4")
cv2.namedWindow('frame',0)
cv2.resizeWindow('frame',300,300)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (300,300))
while(cap.isOpened()):
ret, frame = cap.read()
if ret:
vidout=cv2.resize(frame,(300,300)) #create vidout funct. with res=300x300
out.write(vidout) #write frames of vidout function
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
Thanks for your attention about my question!

I appears to me that you're not doing anything with "out".
You should add:
out.write(frame)
inside the loop.

Related

Video written through OpenCV on Raspberry Pi not running

I was working on saving live feed from USB webcam through opencv on Raspberry PI 4 B+ . Here is the code
import cv2
cap = cv2.VideoCapture(0)
fourcc=cv2.VideoWriter_fourcc(''D','I','V','X'')
out=cv2.VideoWriter('output.mp4',fourcc,25,(640,480))
while True:
ret, frame = cap.read()
cv2.imshow('frame', frame)
out.write(frame)
if cv2.waitKey(1) & 0xFF== ord('q'):
break
cap.release()
cv2.destroyAllWindows()
The video file is created but I am not able to run that file. I also tried with different formats like 'XVID','MJPG','H264' but faced the same issue.
My opencv version is 4.3.038
There are two issues, I would like to address:
Issue #1: DIVX should be declared as:
fourcc = cv2.VideoWriter_fourcc('D', 'I', 'V', 'X')
Issue #2:
You have declared to create the video with the size (640, 480). Therefore each frame you returned should be also (640, 480)
frame = cv2.resize(frame, (640, 480))
But if you use it with DIVX you will have a warning:
OpenCV: FFMPEG: tag 0x58564944/'DIVX' is not supported with codec id 12 and format 'mp4 / MP4 (MPEG-4 Part 14)'
OpenCV: FFMPEG: fallback to use tag 0x7634706d/'mp4v'
Instead of DIVX use mp4v for creating .mp4 videos.
Code:
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc('m', 'p', '4', 'v')
out = cv2.VideoWriter('output.mp4', fourcc, 25, (640, 480), isColor=True)
while True:
ret, frame = cap.read()
frame = cv2.resize(frame, (640, 480))
cv2.imshow('frame', frame)
out.write(frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
You can try this code. Works for me
import cv2
cap = cv2.VideoCapture(0)
video_speed = 15 #This frame rate works well on my case
video_name = 'output.avi'
writer = cv2.VideoWriter(video_name, cv2.VideoWriter_fourcc('M','J','P','G'),video_speed, (640,480))
while True:
ret , frame = cap.read()
if ret == True:
writer.writer(frame)
cv2.imshow('Frame', frame)
if cv2.waitKey(25) & 0xFF == ord('q'):
break
else:
break
cap.release()
writer.release()
cv2.destroyAllWindows()

How to save a video in Python OpenCV

I have opened a Video using CV2, made some changes using cv2.rectangle.
Now, when I do cv2.imshow('frame',frame), it plays the video.
Instead of this, I want to save the video somewhere, in the original size and frame rate.
You can save video frame by frame. Based on example on docs:
Open Cv video capture
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
# write the flipped frame
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()

Why isn't the video feed read by the web camera in python code?

When I run my python opencv code, the web camera does not read a video feed. There are no any errors, but the black color output with wifi sign and loading sign i there. How to fix that and read the video feed. Here is my code and the output.
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))
print(cap.isOpened())
while(cap.isOpened()):
ret, frame = cap.read()
if ret == True:
print(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
print(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
out.write(frame)
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame', gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
If you are only using one camera you can try the following:
cap = cv2.VideoCapture(-1)
This will pick up the first webcam the system can find.
How are you overlaying the wifi/loading signs - I assume they are not part of the webcam feed?

Opencv Writing video as output.avi from video file not from webcam

I am trying to write a video from video file it's not working but when I am using webcam code it's working
there are 2 files one is file.py and the other is web.py
here is my file.py
import numpy as np
import cv2
cap = cv2.VideoCapture('People - 6387.mp4')
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()
and this is my webcam.py this is working properly and writing video
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
out.release()
cv2.destroyAllWindows()`

Python OpenCV Opening Vid File vs. Opening Webcam

I cant figure out why this is not working.
The following code works perfectly using my webcam:
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
# write the flipped frame
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()
Yet when I exchange the Webcam for a video file, the output does not generate a video. Only a 5.7kb file named output.avi:
import numpy as np
import cv2
cap = cv2.VideoCapture('Input.avi')
# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
# write the flipped frame
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()
I can see in my windows that the video is being processed but is not being saved. I have also tried changing the resolution to match the initial video file.
I'm using OpenCV on Ubuntu, and this worked for me:
out = cv2.VideoWriter("output.avi", cv.CV_FOURCC(*'DIVX'), fps, (640, 480))
See if it works on Windows.

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