Develop Reference

How to edit video frames without extracting each frame first ? OpenCV

I am currently extracting frames from a video so I can add some bounding boxes in each frame. Then, I want to put all the frames together and make a new video, using openCV. The problem is that every time I want to do that, I have to extract thousand of frames first. Is there a way to do it without having to extract the frames?
Thanks

That assumption isn't correct. You can use OpenCV's VideoCapture to load a video, get a frame, do some processing on it and save it using a VideoWriter object - one frame at a time. There is no need to load all frames into memory and then store them all at once.

Increase FPS in OpencV -VideoCapture

I read a Video with Opencv Video Capture class, then i convert to Frames.
Now, i Need to increase The Fps or The Frames in my Video(like to create slow motion Video) , I read about Frame Blending To increase Frames in Slow motoin Videos ,So i think i need this way for my problem .
so how actually Frame Blending works or any algorithms to impelement It on Opencv and are there other taqnics to increase frames ?

python write_videofile results in a black screen video

Code:
clip = ImageSequenceClip(new_frames, fps=fps1)
clip.write_videofile("out.mp4", fps=fps1)
TL;DR:
This code produces a black screen video.
where fps1 is from the original video I stitch on
I am trying to stitch a video using frames from many videos.
I created an array containing all the images in their respective place and then passed frame by frame on each video and assigned the correct frame in the array. When I acted that way the result was ok, but the process was slow so I saved each frame to a file and loaded it within the stitching process. Python throw an exception that the array is to big and I chunked the video into parts and saved each chunk. The result came out as a black screen, even thought when I debugged I could show each frame on the ImageSequenceClip correctly. I tried reinstalling moviepy. I use windows 10 and I converted all frames to png type.

Well #BajMile was indeed right offering to use opencv.
What took me a while to realize is that I have to use only functions of opencv, also for the images I was opening and resizing.

how to draw a shape on top of a playing video by clicking a mouse button in opencv python

Well, to begin with, I should admit that it is a pretty long question and I failed to find possible solutions through googling
I have a video in which an intruder tries to intrude into the other side of the fence.
I can track the intruder, but when he is in the other side, I should be able to save the intrusion duration into a file. The intrusion area would be something like this
I thought these steps:
I. Reading a video file;
II. Getting the very first frame displayed,
1. Pausing the video playback;
2. Manually drawing intrusion area on that frame with a mouse; (making draw and reset buttons as events maybe)
3. Replaying the video again
III. Waiting for the intruder to appear, etc. (III part is not important)
So far, I've done I and II (silly, I know) and should accomplish 1,2,3 subparts of step II.
import cv2
file = "intrusion.mp4"
capture = cv2.VideoCapture(file)
ret, firstFrame= capture.read()
while True:
cv2.imshow("First Frame", firstFrame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cv2.destroyAllWindows()
I hope you can give your advice and instructions!
PS: refer to any related posts, blogs or links, I am excited to find out

adding cv2.waitKey(0) will pause your while loop indefinitely! It will resume only after any key press.
I think what you're trying to achieve is object tracking using Background Subtraction. Refer Here and see if it fits your requirements.
EDIT:
I guess you want to draw a freehand shape for intrusion area! This Link will guide you to do it. I hope this helps

frozen frames detection openCV python

I'm trying to detect camera is capturing frozen frames or black frame. Suppose a camera is capturing video frames and suddenly same frame is capturing again and again. I spend long time to get any idea about this problem statement but i failed. So how we detect it or any idea/steps/procedure for this problem.

This was my approach to solve this issue.
Frozen frames: calculate absolute difference over HSV/RGB per every pixel in two consecutive frames np.arrays and determine max allowed diff that is valid for detecting frozen frames.
Black frames have naturally very low (or zero) V-value sum over the frame. Determine max V-sum of whole frame to determine, below which the frame is "black".

You can use this simple opencv method to detect black frame
if (cv::countNonZero(frame) == 0)
{
//do something if frame is black
}