Colour change error in skvideo FFmpeg writer - python

When I am recording videos in skvideo with the following code
import skvideo.io
# open the webcam video stream
webcam = cv2.VideoCapture(0)
print(cv2.__version__)
# open output video file stream
video = skvideo.io.FFmpegWriter("video.avi",{}, {"-q":"0", "-color_primaries": "3", "-color_trc": "1", "-colorspace": "1"})
# main loop
while True:
# get the frame from the webcam
stream_ok, frame = webcam.read()
# if webcam stream is ok
if stream_ok:
# display current frame
cv2.imshow('Webcam', frame)
# write frame to the video file
video.writeFrame(frame)
# escape condition on Esc key pressed
if cv2.waitKey(1) & 0xFF == 27:
break
# clean ups
cv2.destroyAllWindows()
# release web camera stream
webcam.release()
# release video output file stream
video.close()
The colour of the picture is changing
Original
Recording
Can anyone tell me how can I fix it?
I have ffmpeg version git-2020-04-13-59e3a9a Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3.1 (GCC) 20200328
Python version 3.9.6
Opencv version 4.5.4
Skvideo version 1.1.10

Related

How to use hardware decoder for decode RTSP stream in python? (NVidia JetSon Nano)

I have NVIDIA Jetson Nano and FullHD Ip camera.
Camera streams RTSP/h264.
I want to decode frames in python script from this camera for analizies.
So, i tried use something like that:
# import the necessary packages
from imutils.video import VideoStream
import imutils
import time
import cv2
# grab a reference to the webcam
print("[INFO] starting video stream...")
#vs = VideoStream(src=0).start()
vs = VideoStream(src="rtsp://login:password#192.168.1.180").start()
time.sleep(2.0)
# loop over frames
while True:
# grab the next frame
frame = vs.read()
# resize the frame to have a maximum width of 500 pixels
frame = imutils.resize(frame, width=500)
# show the output frame
cv2.imshow("Frame", frame)
key = cv2.waitKey(1) & 0xFF
# if the `q` key was pressed, break from the loop
if key == ord("q"):
break
# release the video stream and close open windows
vs.stop()
cv2.destroyAllWindows()
That's works, but in that way frame decoded on CPU. How to use GPU decoder?
The solution:
Use cv2.VideoCapture with GStreamer backend:
import cv2
pipeline = "rtspsrc location=\"rtsp://login:password#host:port/\" ! rtph264depay ! h264parse ! omxh264dec ! nvvidconv ! video/x-raw, format=(string)BGRx! videoconvert ! appsink"
capture = cv2.VideoCaputure(pipeline, cv2.CAP_GSTREAMER)
while capture.isOpened():
res, frame = capture.read()
cv2.imshow("Video", frame)
key = cv2.waitKey(1) & 0xFF
if key == ord("q"):
break
capture.release()
cv2.destroyAllWindows()

Which OpenCV FOURCC codecs should I use for my Python program?

I have implemented a Python script which displays a video to the user and records it. The video is saved either compressed or uncompressed.
In an old program I have seen, that the "DIVX" MPEG-4 and the "IYUV" codecs were used. For some reason, they don't work on my computer (OUTPUT_VIDEO is a MP4-file).
OpenCV: FFMPEG: tag 0x58564944/'DIVX' is not supported with codec id 13 and format 'mp4 / MP4 (MPEG-4 Part 14)'
OpenCV: FFMPEG: fallback to use tag 0x00000020/' ???'
The "MPJPG" codec works with ".avi" files.
Because I'm not sure about the codecs, I would like to ask, which codecs should I use for my script to achieve the following requirements:
the video sequence can be saved as .mp3, .mp4 file (both compressed) or as .avi file (uncompressed).
Python script should work on Windows and Linux platforms.
This is my source code:
main.py
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import os
import cv2
import platform
#=========== TO CHANGE ===========
INPUT_VIDEO = os.path.join("..", "resources", "video.mp4")
OUTPUT_VIDEO = os.path.join("..", "recorded", "recorded.avi")
compress = False
#=========== TO CHANGE ===========
WINDOW_NAME = "Video Recorder"
player = cv2.VideoCapture(INPUT_VIDEO)
# Get the frames per second (fps) of the video.
fps = player.get(cv2.CAP_PROP_FPS)
# Get width and height via the video capture property.
width = player.get(cv2.CAP_PROP_FRAME_WIDTH)
height = player.get(cv2.CAP_PROP_FRAME_HEIGHT)
# Define the codec and create VideoWriter object according to the used operating system.
four_cc = None
if platform.system() == "Windows":
if compress:
four_cc = cv2.VideoWriter_fourcc(*"MJPG") # *"DIVX") # DIVX MPEG-4 codec.
else:
four_cc = cv2.VideoWriter_fourcc(*"MJPG") # *"IYUV") # Uncompressed yuv420p in avi container.
elif platform.system() == "Linux":
if compress:
four_cc = cv2.VideoWriter_fourcc(*"DIVX") # DIVX MPEG-4 codec.
else:
four_cc = cv2.VideoWriter_fourcc(*"IYUV") # Uncompressed yuv420p in avi container.
recorder = cv2.VideoWriter(OUTPUT_VIDEO, four_cc, fps, (int(width), int(height)))
if player is None:
quit()
while player.isOpened():
ret, frame = player.read()
if ret:
cv2.imshow(WINDOW_NAME, frame)
recorder.write(frame)
else:
break
key_code = cv2.waitKey(1)
# Closes the window if the ESC key was pressed.
if key_code == 27:
break
# Closes the window if the X button of the window was clicked.
if cv2.getWindowProperty(WINDOW_NAME, 1) == -1:
break
player.release()
recorder.release()
cv2.destroyAllWindows()
I'm using a Windows 7 computer, with opencv-contrib-python 3.4.0.12 and Python 3.6.

Read a video file from an URL and parse it using OpenCV [duplicate]

Given its link, I'd like to capture an online video (say from YouTube) for further processing without downloading it on the disk. What I mean by this is that I'd like to load it directly to memory whenever possible. According to these links:
http://answers.opencv.org/question/24012/reading-video-stream-from-ip-camera-in-opencv-java/#24013
http://answers.opencv.org/question/24154/how-to-using-opencv-api-get-web-video-stream/#24156
http://answers.opencv.org/question/133/how-do-i-access-an-ip-camera/
https://pypi.org/project/pafy/
it should be doable. My attempt looks like this:
import cv2
import pafy
vid = pafy.new("https://www.youtube.com/watch?v=QuELiw8tbx8")
vid_cap = cv2.VideoCapture()
vid_cap.open(vid.getbest(preftype="webm").url)
However it fails with an error
(python:12925): GLib-GObject-CRITICAL **: 14:48:56.168: g_object_set: assertion 'G_IS_OBJECT (object)' failed
False
How can I achieve my goal using python?
You can achieve this by using youtube-dl and ffmpeg:
Install the latest version of youtube-dl.
Then do sudo pip install --upgrade youtube_dl
Build ffmpeg with HTTPS support. You can do this by turning on the --enable-gnutls option.
Once the installations are complete, it's time to test the youtube-dl in terminal. We'll be using this youtube video for testing.
First we get the list of formats available for this video:
youtube-dl --list-formats https://www.youtube.com/watch?v=HECa3bAFAYk
Select a format code of your choice. I want the 144p resolution so I select 160.
Next we get the video url for our format of choice by:
youtube-dl --format 160 --get-url https://www.youtube.com/watch?v=HECa3bAFAYk
https://r3---sn-4g5e6nz7.googlevideo.com/videoplayback?clen=184077&aitags=133%2C134%2C160%2C242%2C243%2C278&fvip=3&requiressl=yes&signature=5D21FFD906226C7680B26ACEF996B78B6A31F7C9.31B1115DB13F096AA5968DB2838E22A0D6A2EDCB&source=youtube&mn=sn-4g5e6nz7%2Csn-h0jeen7y&xtags=tx%3D9486108&itag=160&mime=video%2Fmp4&mt=1529091799&ms=au%2Conr&ei=XxckW-73GNCogQfqrryQAg&expire=1529113535&mm=31%2C26&c=WEB&keepalive=yes&id=o-AJExEG49WtIUkrF7OikaaGBCfKntDl75xCoO5_9cL-eP&ip=95.91.202.147&sparams=aitags%2Cclen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Ckeepalive%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cxtags%2Cexpire&key=yt6&lmt=1526699176943888&dur=25.375&pl=22&gir=yes&mv=m&initcwndbps=1155000&ipbits=0&ratebypass=yes
Finally we can play this video url in either ffplay or vlc. But instead of copying and pasting, we can do this in one command:
ffplay -i $(youtube-dl --format 160 --get-url https://www.youtube.com/watch?v=HECa3bAFAYk)
Now that we have confirmed that youtube-dl and ffmpeg works, we can write a Python script to process the frames in OpenCV. See this link for more Python options.
import cv2
import numpy as np
import youtube_dl
if __name__ == '__main__':
video_url = 'https://www.youtube.com/watch?v=HECa3bAFAYkq'
ydl_opts = {}
# create youtube-dl object
ydl = youtube_dl.YoutubeDL(ydl_opts)
# set video url, extract video information
info_dict = ydl.extract_info(video_url, download=False)
# get video formats available
formats = info_dict.get('formats',None)
for f in formats:
# I want the lowest resolution, so I set resolution as 144p
if f.get('format_note',None) == '144p':
#get the video url
url = f.get('url',None)
# open url with opencv
cap = cv2.VideoCapture(url)
# check if url was opened
if not cap.isOpened():
print('video not opened')
exit(-1)
while True:
# read frame
ret, frame = cap.read()
# check if frame is empty
if not ret:
break
# display frame
cv2.imshow('frame', frame)
if cv2.waitKey(30)&0xFF == ord('q'):
break
# release VideoCapture
cap.release()
cv2.destroyAllWindows()
First of all Update youtube-dl using the command pip install -U youtube-dl
Then use my VidGear Python Library, then automates the pipelining of YouTube Video using its URL address only. Here's a complete python example:
For VidGear v0.1.9 below:
# import libraries
from vidgear.gears import CamGear
import cv2
stream = CamGear(source='https://youtu.be/dQw4w9WgXcQ', y_tube = True, logging=True).start() # YouTube Video URL as input
# infinite loop
while True:
frame = stream.read()
# read frames
# check if frame is None
if frame is None:
#if True break the infinite loop
break
# do something with frame here
cv2.imshow("Output Frame", frame)
# Show output window
key = cv2.waitKey(1) & 0xFF
# check for 'q' key-press
if key == ord("q"):
#if 'q' key-pressed break out
break
cv2.destroyAllWindows()
# close output window
# safely close video stream.
stream.stop()
For VidGear v0.2.0 and above: (y_tube changed to stream_mode)
# import libraries
from vidgear.gears import CamGear
import cv2
stream = CamGear(source='https://youtu.be/dQw4w9WgXcQ', stream_mode = True, logging=True).start() # YouTube Video URL as input
# infinite loop
while True:
frame = stream.read()
# read frames
# check if frame is None
if frame is None:
#if True break the infinite loop
break
# do something with frame here
cv2.imshow("Output Frame", frame)
# Show output window
key = cv2.waitKey(1) & 0xFF
# check for 'q' key-press
if key == ord("q"):
#if 'q' key-pressed break out
break
cv2.destroyAllWindows()
# close output window
# safely close video stream.
stream.stop()
Code Source
If still get some error, raise an issue here in its GitHub repo.
Using pafy you can have a more elegant solution:
import cv2
import pafy
url = "https://www.youtube.com/watch?v=NKpuX_yzdYs"
video = pafy.new(url)
best = video.getbest(preftype="mp4")
capture = cv2.VideoCapture()
capture.open(best.url)
success,image = capture.read()
while success:
cv2.imshow('frame', image)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
success,image = capture.read()
cv2.destroyAllWindows()
capture.release()
I want to highlight the issue I faced while running was a open-cv version problem, I was using OpenCV 3.4.x and the video feed was exiting before being read into the while loop, so, i upgraded my open cv to "opencv-contrib-python== 4.2.0.34".

Capture YouTube video for further processing without downloading the video

Given its link, I'd like to capture an online video (say from YouTube) for further processing without downloading it on the disk. What I mean by this is that I'd like to load it directly to memory whenever possible. According to these links:
http://answers.opencv.org/question/24012/reading-video-stream-from-ip-camera-in-opencv-java/#24013
http://answers.opencv.org/question/24154/how-to-using-opencv-api-get-web-video-stream/#24156
http://answers.opencv.org/question/133/how-do-i-access-an-ip-camera/
https://pypi.org/project/pafy/
it should be doable. My attempt looks like this:
import cv2
import pafy
vid = pafy.new("https://www.youtube.com/watch?v=QuELiw8tbx8")
vid_cap = cv2.VideoCapture()
vid_cap.open(vid.getbest(preftype="webm").url)
However it fails with an error
(python:12925): GLib-GObject-CRITICAL **: 14:48:56.168: g_object_set: assertion 'G_IS_OBJECT (object)' failed
False
How can I achieve my goal using python?
You can achieve this by using youtube-dl and ffmpeg:
Install the latest version of youtube-dl.
Then do sudo pip install --upgrade youtube_dl
Build ffmpeg with HTTPS support. You can do this by turning on the --enable-gnutls option.
Once the installations are complete, it's time to test the youtube-dl in terminal. We'll be using this youtube video for testing.
First we get the list of formats available for this video:
youtube-dl --list-formats https://www.youtube.com/watch?v=HECa3bAFAYk
Select a format code of your choice. I want the 144p resolution so I select 160.
Next we get the video url for our format of choice by:
youtube-dl --format 160 --get-url https://www.youtube.com/watch?v=HECa3bAFAYk
https://r3---sn-4g5e6nz7.googlevideo.com/videoplayback?clen=184077&aitags=133%2C134%2C160%2C242%2C243%2C278&fvip=3&requiressl=yes&signature=5D21FFD906226C7680B26ACEF996B78B6A31F7C9.31B1115DB13F096AA5968DB2838E22A0D6A2EDCB&source=youtube&mn=sn-4g5e6nz7%2Csn-h0jeen7y&xtags=tx%3D9486108&itag=160&mime=video%2Fmp4&mt=1529091799&ms=au%2Conr&ei=XxckW-73GNCogQfqrryQAg&expire=1529113535&mm=31%2C26&c=WEB&keepalive=yes&id=o-AJExEG49WtIUkrF7OikaaGBCfKntDl75xCoO5_9cL-eP&ip=95.91.202.147&sparams=aitags%2Cclen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Ckeepalive%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cxtags%2Cexpire&key=yt6&lmt=1526699176943888&dur=25.375&pl=22&gir=yes&mv=m&initcwndbps=1155000&ipbits=0&ratebypass=yes
Finally we can play this video url in either ffplay or vlc. But instead of copying and pasting, we can do this in one command:
ffplay -i $(youtube-dl --format 160 --get-url https://www.youtube.com/watch?v=HECa3bAFAYk)
Now that we have confirmed that youtube-dl and ffmpeg works, we can write a Python script to process the frames in OpenCV. See this link for more Python options.
import cv2
import numpy as np
import youtube_dl
if __name__ == '__main__':
video_url = 'https://www.youtube.com/watch?v=HECa3bAFAYkq'
ydl_opts = {}
# create youtube-dl object
ydl = youtube_dl.YoutubeDL(ydl_opts)
# set video url, extract video information
info_dict = ydl.extract_info(video_url, download=False)
# get video formats available
formats = info_dict.get('formats',None)
for f in formats:
# I want the lowest resolution, so I set resolution as 144p
if f.get('format_note',None) == '144p':
#get the video url
url = f.get('url',None)
# open url with opencv
cap = cv2.VideoCapture(url)
# check if url was opened
if not cap.isOpened():
print('video not opened')
exit(-1)
while True:
# read frame
ret, frame = cap.read()
# check if frame is empty
if not ret:
break
# display frame
cv2.imshow('frame', frame)
if cv2.waitKey(30)&0xFF == ord('q'):
break
# release VideoCapture
cap.release()
cv2.destroyAllWindows()
First of all Update youtube-dl using the command pip install -U youtube-dl
Then use my VidGear Python Library, then automates the pipelining of YouTube Video using its URL address only. Here's a complete python example:
For VidGear v0.1.9 below:
# import libraries
from vidgear.gears import CamGear
import cv2
stream = CamGear(source='https://youtu.be/dQw4w9WgXcQ', y_tube = True, logging=True).start() # YouTube Video URL as input
# infinite loop
while True:
frame = stream.read()
# read frames
# check if frame is None
if frame is None:
#if True break the infinite loop
break
# do something with frame here
cv2.imshow("Output Frame", frame)
# Show output window
key = cv2.waitKey(1) & 0xFF
# check for 'q' key-press
if key == ord("q"):
#if 'q' key-pressed break out
break
cv2.destroyAllWindows()
# close output window
# safely close video stream.
stream.stop()
For VidGear v0.2.0 and above: (y_tube changed to stream_mode)
# import libraries
from vidgear.gears import CamGear
import cv2
stream = CamGear(source='https://youtu.be/dQw4w9WgXcQ', stream_mode = True, logging=True).start() # YouTube Video URL as input
# infinite loop
while True:
frame = stream.read()
# read frames
# check if frame is None
if frame is None:
#if True break the infinite loop
break
# do something with frame here
cv2.imshow("Output Frame", frame)
# Show output window
key = cv2.waitKey(1) & 0xFF
# check for 'q' key-press
if key == ord("q"):
#if 'q' key-pressed break out
break
cv2.destroyAllWindows()
# close output window
# safely close video stream.
stream.stop()
Code Source
If still get some error, raise an issue here in its GitHub repo.
Using pafy you can have a more elegant solution:
import cv2
import pafy
url = "https://www.youtube.com/watch?v=NKpuX_yzdYs"
video = pafy.new(url)
best = video.getbest(preftype="mp4")
capture = cv2.VideoCapture()
capture.open(best.url)
success,image = capture.read()
while success:
cv2.imshow('frame', image)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
success,image = capture.read()
cv2.destroyAllWindows()
capture.release()
I want to highlight the issue I faced while running was a open-cv version problem, I was using OpenCV 3.4.x and the video feed was exiting before being read into the while loop, so, i upgraded my open cv to "opencv-contrib-python== 4.2.0.34".

OpenCV cv2 not working in Windows 7

I have a Windows 7 SP1 64 Bit machine with open cv2.4.9 installed and python 2.7.6 installed.
I use pre compiled version of opencv
The following code works perfectly for me
import cv2.cv as cv
import time
cv.NamedWindow("camera", 0)
capture = cv.CaptureFromCAM(0)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("camera", img)
if cv.WaitKey(10) == 27:
break
cv.DestroyAllWindows()
Now when I try to use this code
import cv2
import numpy as np
cam = cv2.VideoCapture(0)
s, img = cam.read()
winName = "Movement Indicator"
cv2.namedWindow(winName, cv2.CV_WINDOW_AUTOSIZE)
while s:
cv2.imshow( winName,img )
s, img = cam.read()
key = cv2.waitKey(10)
if key == 27:
cv2.destroyWindow(winName)
break
print "Goodbye"
The window is opened , the camera is initialized (as camera lights are on) , but nothing is displayed and the window closes and the program exits.
WHERE am I going wrong??
QUESTION 2
Can any one also suggest me how to capture live video stream from my Linux machine 192.168.1.3 . The stream is being generated by ffmpeg.
The video stream can be opened in web browser. But I want to capture it with opencv and python.

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