I'm trying to grab the images from a video file but I can't succeed to open it and I don't know why.
Below is a code sample that print False where I'm expecting to get a True. I don't get why I can't open this simple video file, any lead would be very much appreciated!
I tried with a relative path first then moved to an absolute path to see if anything changed and it's still the same...
video = cv2.VideoCapture()
path = "C:\\Users\\Leo\\Dropbox\\Projet VISORD\\TP3\\video.mpg"
print video.open(path)
The codecs that cv2 supports out of the box are limited. A few of the formats can be found at the link below. I haven't tried them all yet.
http://opencv.willowgarage.com/wiki/documentation/cpp/highgui/VideoWriter
I've had some luck with mp42 codec. Had to convert my camera's mp4 (h264) format to an avi in the correct format.
Using a tool ffmpeg at the moment.
ffmpeg -i input.mp4 -codec:v msmpeg4v2 output.avi
This still leaves something to be desired as it loses resolution, so I am working toward a better solution myself. I only just started at this myself.
The following code works for me:
import cv2
Load the video file:
capture = cv2.VideoCapture('videos/my_video.avi')
Frame is the image you want, flag is success/failure:
flag, frame = capture.read()
Loop through the video's frames:
while True:
flag, frame = capture.read()
if flag == 0:
break
cv2.imshow("Video", frame)
key_pressed = cv2.waitKey(10) #Escape to exit
if key_pressed == 27:
break
However, MPEG is a compressed format, which means that you need the correct codecs to be installed and might have to do some more work to handle the conversion. You can read about the supported different types of video formats at the OpenCV VideoCodec documentation.
(However, if you just want a simple working example, try using a .AVI file and see if it works for you.)
Had a similar problem. Try changing
path = "C:\\Users\\Leo\\Dropbox\\Projet VISORD\\TP3\\video.mpg"
to
path = "C:/Users/Leo/Dropbox/Projet VISORD/TP3/video.mpg"
and see if it works.
Related
I have been using Moviepy to combine several shorter video files into hour long files. Some small files are "broken", they contain video but was not completed correctly (i.e. they play with VLC but there is no duration and you cannot skip around in the video).
I noticed this issue when I try to create a clip using VideoFileClip(file) function. The error that comes up is:
MoviePy error: failed to read the duration of file
Is there a way to still read the "good" frames from this video file and then add them to the longer video?
UPDATE
To clarify, my issue specifically is with the following function call:
clip = mp.VideoFileClip("/home/test/"+file)
Stepping through the code it seems to be an issue when checking the duration of the file in ffmpeg_reader.py where it looks for the duration parameter in the video file. However, since the file never finished recording properly this information is missing. I'm not very familiar with the way video files are structured so I am unsure of how to proceed from here.
You're correct. This issue arises commonly when the video duration info is missing from the file.
Here's a thread on the issue: GitHub moviepy issue 116
One user proposed the solution of using MP4Box to convert the video using this guide: RASPIVID tutorial
The final solution that worked for me involved specifying the path to ImageMagick's binary file as WDBell mentioned in this post.
I had the path correctly set in my environment variables, but it wasn't till I specificaly defined it in config_defaults.py that it started working:
I solved it in a simpler way, with the help of VLC I converted the file to the forma MPEG4 xxx TV/device,
and you can now use your new file with python without any problem
xxx = 720p or
xxx = 1080p
everything depends on your choice on the output format
I already answered this question on the blog: https://github.com/Zulko/moviepy/issues/116
This issue appears when VideoFileClip(file) function from moviepy it looks for the duration parameter in the video file and it's missing. To avoid this (in those corrupted files cases) you should make sure that the total frames parameter is not null before to shoot the function: clip = mp.VideoFileClip("/home/test/"+file)
So, I handled it in a simpler way using cv2.
The idea:
find out the total frames
if frames is null, then call the writer of cv2 and generate a temporary copy of the video clip.
mix the audio from the original video with the copy.
replace the original video and delete copy.
then call the function clip = mp.VideoFileClip("/home/test/"+file)
Clarification: Since OpenCV VideoWriter does not encode audio, the new copy will not contain audio, so it would be necessary to extract the audio from the original video and then mix it with the copy, before replacing it with the original video.
You must import cv2
import cv2
And then add something like this in your code before the evaluation:
cap = cv2.VideoCapture("/home/test/"+file)
frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
fps = int(cap.get(cv2.CAP_PROP_FPS))
print(f'Checking Video {count} Frames {frames} fps: {fps}')
This will surely return 0 frames but should return at least framerate (fps).
Now we can set the evaluation to avoid the error and handle it making a temp video:
if frames == 0:
print(f'No frames data in video {file}, trying to convert this video..')
writer = cv2.VideoWriter("/home/test/fixVideo.avi", cv2.VideoWriter_fourcc(*'DIVX'), int(cap.get(cv2.CAP_PROP_FPS)),(int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))))
while True:
ret, frame = cap.read()
if ret is True:
writer.write(frame)
else:
cap.release()
print("Stopping video writer")
writer.release()
writer = None
break
Mix the audio from the original video with the copy. I have created a function for this:
def mix_audio_to_video(pathVideoInput, pathVideoNonAudio, pathVideoOutput):
videoclip = VideoFileClip(pathVideoInput)
audioclip = videoclip.audio
new_audioclip = CompositeAudioClip([audioclip])
videoclipNew = VideoFileClip(pathVideoNonAudio)
videoclipNew.audio = new_audioclip
videoclipNew.write_videofile(pathVideoOutput)
mix_audio_to_video("/home/test/"+file, "/home/test/fixVideo.avi", "/home/test/fixVideo.mp4")
replace the original video and delete copys:
os.replace("/home/test/fixVideo.mp4", "/home/test/"+file)
I had the same problem and I have found the solution.
I don't know why but if we enter the path in this method path = r'<path>' instead of ("F:\\path") we get no error.
Just click on the
C:\Users\gladi\AppData\Local\Programs\Python\Python311\Lib\site-packages\moviepy\video\io\ffmpeg_reader.py
and delete the the code and add this one
Provided by me in GITHUB - https://github.com/dudegladiator/Edited-ffmpeg-for-moviepy
clip1=VideoFileClip('path')
c=clip1.duration
print(c)
I am using Python 2.7.11 and OpenCV 2.4.9. I cannot read a video by using cv2.imread() or cv2.VideoCapture().
import cv2
cap = cv2.VideoCapture('cam.avi')
print ("open = ",cap.isOpened())
OR
import cv2
cap = cv2.imread('cam.avi')
print ("open = ",cap.isOpened())
It will return false.
I don't know why. I am sure that the cam.avi is here.
imread() does not support reading from video files directly.
See also the documentation of OpenCV.
If you want to read a video with imread you will first have to convert it to single images, either via a serperate program (ffmpeg comes to mind) or using OpenCV and store the images in memory.
Try providing full path to video, like:
import cv2
cap = cv2.VideoCapture(r'C:\Users\e01069\Downloads\drop.avi')
print ("open = ",cap.isOpened())
If you run following in your same file, you would know that python is looking for your file on some different location.
import os
print os.path.abspath(__file__) #this is your current working directory
Note: .imread wouldn't work this way.
I am using the following code to access my webcam using openCV + python...
import cv
cv.NamedWindow('webcam_feed', cv.CV_WINDOW_AUTOSIZE)
cam = cv.CaptureFromCAM(-1)
I am then getting the following error in the console...
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
VIDIOC_QUERYMENU: Invalid argument
I was originally using,
cv.CaptureFromCAM(0)
to access the same and had the same issue and used -1 because it is suppose to pick up any webcam.
I also tested to see if Ubuntu recognizes the webcam and it does. I am using v4l2 for the webcam.
{EDIT}
I am using the following code to display a video feed, it seems to only be showing just one image the web cam captured instead of a continuous video feed...
import cv
cv.NamedWindow('webcam_feed', cv.CV_WINDOW_AUTOSIZE)
cam = cv.CaptureFromCAM(-1)
feed = cv.QueryFrame(cam)
cv.ShowImage("webcam_feed", feed)
cv.WaitKey(-1)
WOW, answered my own question in 15 after me posting this. I did some research and the reason for the web cam only grabbing one image is because of the...
cv.WaitKey(-1)
This doesn't allow the contents of the window to refresh. I set the number to 10...
cv.WaitKey(10)
and it worked beautifully. I also tried 100, but saw no difference. I only saw a difference when the number was 1000. I use 1 because seems that it runs the smoothest.
Here is the full code to display a web cam feed
import cv
cv.NamedWindow("webcam", 1)
cam = cv.CaptureFromCAM(-1)
While True:
feed = cv.QueryFrame(cam)
cv.ShowImage("webcam", feed)
cv.WaitKey(1)
I believe you need to put
frame = cv.QueryFrame(cam)
cv.ShowImage("Webcam Feed", frame)
in a loop to continuously update the image shown in the window. That is, the frame from cv.QueryFrame is a static image, not a continuous video.
If you want to be able to exit with a key press, test cv.WaitKey with a small timeout in the loop too.
For me, the command in root
xhost +
save my time, Note to close and open new terminal.
See you.
I'm new to python and Opencv and I tried to put in the following code to save an image to my computer from my webcam:
import cv
if __name__=='__main__':
pCapturedImage = cv.CaptureFromCAM(1)
rospy.sleep(0.5)
pSaveImg=cv.QueryFrame(pCapturedImage)
cv.SaveImage("test.jpg", pSaveImg)
But when I try to open it,
I find that the jpeg is empty.
Could someone please help?
Also, I tried a program to show what my webcam is seeing:
import cv
if __name__=='__main__':
cv.NamedWindow("camera",1)
capture=cv.CaptureFromCAM(0)
while True:
img=cv.QueryFrame(capture)
cv.ShowImage("camera", img)
if cv.WaitKey(10)==27:
break
cv.DestroyedWindow("camera")
But when I run it, I get an application that just shows me a gray screen.
Could someone help with this too?
Thanks.
Have you tried the demo programs? They show how to use the webcam among many other things.
For the first problem, I am not familiar with using cameras in opencv, but I got it to work by opening the capture (capture.open(device_id) in the code below)
Here is a working python sample (I use the newer c++ interface: imread, imwrite, VideoCapture, etc... which you can find in the OpenCV docs listed as "cv2" when it is available for python.):
import cv2
capture = cv2.VideoCapture() # this is the newer c++ interface
capture.open(0) # Use your device id; I think this is what you are missing.
image = capture.read()[1]
cv2.imwrite("test.jpg", image)
I got your second sample also working just by using open on the capture object:
import cv2
cv2.namedWindow("camera", 1) # this is where you will put the video images
capture = cv2.VideoCapture()
capture.open(0) # again, use your own device id
while True:
img = capture.read()[1]
cv2.imshow("camera", img)
if cv2.waitKey(10) == 27: # waiting for the esc key
break
cv2.destroyWindow("camera")
I need to split big video file into smaller pieces by time. Give me your suggestions, please, and if you can some tips for library usage. Thanks.
OpenCV has Python wrappers.
As you're interested in video IO, have a look at QueryFrame and its related functions there.
In the end, your code will look something like this (completely untested):
import cv
capture = cv.CaptureFromFile(filename)
while Condition1:
# Need a frame to get the output video dimensions
frame = cv.RetrieveFrame(capture) # Will return None if there are no frames
# New video file
video_out = cv.CreateVideoWriter(output_filenameX,
CV_FOURCC('M','J','P','G'), capture.fps, frame.size(), 1)
# Write the frames
cv.WriteFrame(video_out, frame)
while Condition2:
# Will return None if there are no frames
frame = cv.RetrieveFrame(capture)
cv.WriteFrame(video_out, frame)
By the way, there are also ways to do this without writing any code.
Check youtube-upload, it splits the videos using ffmpeg.
Youtube-upload is a command-line
script that uploads videos to Youtube.
If a video does not comply with
Youtube limitations (<2Gb and <15'),
it will be automatically splitted
before uploading. Youtube-upload
should work on any platform
(GNU/Linux, BSD, OS X, Windows, ...)
that runs Python and FFmpeg.