I want to read a live stream from youtube to perform some basic CV things, probably we have to somehow strip of the youtube URL to convert it in a format that might be readable by openCV like?:
cap = cv2.VideoCapture('https://www.youtube.com/watch?v=_9OBhtLA9Ig')
has anyone done it?
I am sure you already know the answer by now, but I will answer for others searching the same topic. You can do this by using Pafy
(probably together with youtube_dl).
import pafy
import cv2
url = "https://www.youtube.com/watch?v=_9OBhtLA9Ig"
video = pafy.new(url)
best = video.getbest(preftype="mp4")
capture = cv2.VideoCapture(best.url)
while True:
grabbed, frame = capture.read()
# ...
And that should be it.
I've added Youtube URL source support in my VidGear Python Library that automatically pipelines YouTube Video into OpenCV by providing its URL only. Here is a complete python example:
# 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
After 100-120 frames the answer from #lee hannigan was crashing on me for a live stream on youtube.
I worked out a method with Pafy to just grab x number of frames and splice them together. This ended up poorly stitching the chunks together though, and gave choppy results. Pafy may not be designed for live streams, I couldn't find a way to stitch the frames together seamlessly.
What worked in the end is below, slightly modified from guttentag_liu's answer on this post. It takes a few more packages, and is lengthy, but works. Because the file is live, it needs to be in chunks, hence saving to a temporary file. You could probably do your openCV work on each chunk, then save to a file in the end instead of re-opening.
# pip install urllib
# pip install m3u8
# pip install streamlink
from datetime import datetime, timedelta, timezone
import urllib
import m3u8
import streamlink
import cv2 #openCV
def get_stream(url):
"""
Get upload chunk url
input: youtube URL
output: m3u8 object segment
"""
#Try this line tries number of times, if it doesn't work,
# then show the exception on the last attempt
# Credit, theherk, https://stackoverflow.com/questions/2083987/how-to-retry-after-exception
tries = 10
for i in range(tries):
try:
streams = streamlink.streams(url)
except:
if i < tries - 1: # i is zero indexed
print(f"Attempt {i+1} of {tries}")
time.sleep(0.1) #Wait half a second, avoid overload
continue
else:
raise
break
stream_url = streams["best"] #Alternate, use '360p'
m3u8_obj = m3u8.load(stream_url.args['url'])
return m3u8_obj.segments[0] #Parsed stream
def dl_stream(url, filename, chunks):
"""
Download each chunk to file
input: url, filename, and number of chunks (int)
output: saves file at filename location
returns none.
"""
pre_time_stamp = datetime(1, 1, 1, 0, 0, tzinfo=timezone.utc)
#Repeat for each chunk
#Needs to be in chunks because
# 1) it's live
# 2) it won't let you leave the stream open forever
i=1
while i <= chunks:
#Open stream
stream_segment = get_stream(url)
#Get current time on video
cur_time_stamp = stream_segment.program_date_time
#Only get next time step, wait if it's not new yet
if cur_time_stamp <= pre_time_stamp:
#Don't increment counter until we have a new chunk
print("NO pre: ",pre_time_stamp, "curr:",cur_time_stamp)
time.sleep(0.5) #Wait half a sec
pass
else:
print("YES: pre: ",pre_time_stamp, "curr:",cur_time_stamp)
print(f'#{i} at time {cur_time_stamp}')
#Open file for writing stream
file = open(filename, 'ab+') #ab+ means keep adding to file
#Write stream to file
with urllib.request.urlopen(stream_segment.uri) as response:
html = response.read()
file.write(html)
#Update time stamp
pre_time_stamp = cur_time_stamp
time.sleep(stream_segment.duration) #Wait duration time - 1
i += 1 #only increment if we got a new chunk
return None
def openCVProcessing(saved_video_file):
'''View saved video with openCV
Add your other steps here'''
capture = cv2.VideoCapture(saved_video_file)
while capture.isOpened():
grabbed, frame = capture.read() #read in single frame
if grabbed == False:
break
#openCV processing goes here
#
cv2.imshow('frame',frame) #Show the frame
#Shown in a new window, To exit, push q on the keyboard
if cv2.waitKey(20) & 0xFF == ord('q'):
break
capture.release()
cv2.destroyAllWindows() #close the windows automatically
tempFile = "temp.ts" #files are format ts, open cv can view them
videoURL = "https://www.youtube.com/watch?v=_9OBhtLA9Ig"
dl_stream(videoURL, tempFile, 3)
openCVProcessing(tempFile)
Probably, because Youtube does not provide the like/dislike counts anymore, the first solution gives error. As a solution, you should comment the 53rd and 54th lines in the backend_youtube_dl.py in pafy package file as in the image below, after that the code in the first solution will work:
Secondly, you can get not get audio with OpenCV, it is a computer vision library, not multimedia. You should try other options for that.
Related
I am testing different background segmentation algorithm from the library pybgs. Unfortunately, I am facing an error that I don't understand.
The code is :
import cv2
import pybgs as bgs
video_path = "video.mp4"
# create VideoCapture object for further video processing
captured_video = cv2.VideoCapture(video_path)
# check video capture status
if not captured_video.isOpened:
print("Unable to open: " + video_path)
exit(0)
background_sub_method = bgs.SuBSENSE()
while True:
# read video frames
ret, frame = captured_video.read()
# check whether the frames have been grabbed
if not ret:
break
# pass the frame to the background subtractor
foreground_mask = background_sub_method.apply(frame)
# obtain the background without foreground mask
img_bg_model = background_sub_method.getBackgroundModel()
cv2.imshow("Initial Frame", frame)
cv2.imshow("FG Mask", foreground_mask)
cv2.imshow("Subtraction Result", img_bg_model)
key = cv2.waitKey(10)
if key == 27:
break
Except that the algorithm don't work properly, I get this error that I don't understand.
[ERROR:0#0.002] global /home/usr/opencv-4.x/modules/core/src/persistence.cpp (505) open Can't open file: './config/SuBSense.xml' in write mode
Failed to open ./config/SuBSense.xml
In my lib pybgs, I have a config folder but there is no SuBSense.xml file.
So I don't know where this error is from, where this SuBSense.xml file is suppose to be.
I'm trying to write a simple time lapse desktop video recorder which you can use to append to the same file over multiple sessions, and the following code works, however it requires encoding with ffmpeg to set an fps that isn't a default 25. I want to avoid using cv2 so i'm going the long way around this problem.
So what would be a way to write the video to include an fps setting of some sort, without having to re-encode with ffmpeg.
import fpstimer
from typing import BinaryIO
from io import BytesIO
from PIL import Image, ImageGrab
timer = fpstimer.FPSTimer(0.2)
def video(chunk: bytes, file_handler: BinaryIO):
file_handler.write(chunk)
while True:
try:
frame = ImageGrab.grab().convert('RGB')
buf = BytesIO()
frame.save(buf, format='PNG')
byte_im = buf.getvalue()
with open('output.mp4', "ab") as fh:
video(byte_im, fh)
timer.sleep()
except KeyboardInterrupt:
print('done')
raise
I was reading the book 'Automating the boring stuff with python' where I read about webbrowser module. I tried to make a program that downloads a given number of videos from the web. But since Chrome starts multiple downloads simultaneously, I wondered if there could be some code which could replace the comments in my code listed below.
# This is a program to download a list of episodes
import webbrowser, sys
start = int(sys.argv[1]) # denotes the starting episode number
stop = int(sys.argv[2]) # denotes the final episode number
while start <= stop:
link = #(first half of link) + str(start) + #(final half of link)
#here goes the code that checks the size of the video to be downloaded
webbrowser.open(link)
while True:
# here goes an if statement that keeps checking the size of the downloaded file
start += 1
break
else:
continue
Edit 1:
I have deduced a part of my original question which repeatedly checks the downloaded size. However, the code which actually lets me know of the file size before downloading is still out of my knowledge
# This is a program to download a list of episodes
import webbrowser, sys, os
start = int(sys.argv[1]) # denotes the starting episode number
stop = int(sys.argv[2]) # denotes the final episode number
while start <= stop:
link = #(first half of link) + str(start) + #(final half of link)
file = #name under which video will be downloaded
os.chdir(r'C:\Users\OWNER\Downloads')
#here goes the code that checks the size of the video to be downloaded
webbrowser.open(link)
while True:
if os.path.getsize(file) >= # size of file to be downloaded:
start += 1
break
else:
continue
I have been trying to download a video file with python and at the same time playing it with VLC.
I have tried few ways. One of them is to download in a single thread with continuous fetch and append data. This style is slow but video plays. The code is something like below
self.fp = open(dest, "w")
while not self.stop_down and _continue: with urllib2 request
try:
size = 1024 * 8
data = page.read(size)
bytld+= size
self.fp.write(data)
This function takes longer to download but I am able to play the video while its loading.
However I have been trying to download in multiple parts at the same time..
With proper threading logics
req= urllib2.Request(self.url)
req.headers['Range'] = 'bytes=%s-%s' % (self.startPos, self.end)
response = urllib2.urlopen(req)
content = response.read()
if os.path.exists(self.dest) :
out_fd = open(self.dest, "r+b")
else :
out_fd = open(self.dest, "w+b")
out_fd.seek(self.startPos, 0)
out_fd.write(content)
out_fd.close()
With my threading I am making sure that each part of the file is being saved on sequentially.
But for some reason I can't play this file at all while downloading.
Is there anything I am not doing right? Is the "Range" should be modified different way?
Turns out for each block of data in thread mode Range has to be +1 BYTE. So if the first block is 1024 next one is from 1023 to whatever.
I have a script for downloading the Questionable Content webcomic. It looks like it runs okay, but the files it downloads are empty, only a few kb in size.
#import Web, Reg. Exp, and Operating System libraries
import urllib, re, os
#RegExp for the EndNum variable
RegExp = re.compile('.*<img src="http://www.questionablecontent.net/comics.*')
#Check the main QC page
site = urllib.urlopen("http://questionablecontent.net/")
contentLine = None
#For each line in the homepage's source...
for line in site.readlines():
#Break when you find the variable information
if RegExp.search(line):
contentLine = line
break
#IF the information was found successfuly automatically change EndNum
#ELSE set it to the latest comic as of this writing
if contentLine:
contentLine = contentLine.split('/')
contentLine = contentLine[4].split('.')
EndNum = int(contentLine[0])
else:
EndNum = 2622
#First and Last comics user wishes to download
StartNum = 1
#EndNum = 2622
#Full path of destination folder needs to pre-exist
destinationFolder = "D:\Downloads\Comics\Questionable Content"
#XRange creates an iterator to go over the comics
for i in xrange(StartNum, EndNum+1):
#IF you already have the comic, skip downloading it
if os.path.exists(destinationFolder+"\\"+str(i)+".png"):
print "Skipping Comic "+str(i)+"..."
continue
#Printing User-Friendly Messages
print "Comic %d Found. Downloading..." % i
source = "http://www.questionablecontent.net/comics/"+str(i)+".png"
#Save image from XKCD to Destination Folder as a PNG (As most comics are PNGs)
urllib.urlretrieve(source, os.path.join(destinationFolder, str(i)+".png"))
#Graceful program termination
print str(EndNum-StartNum) + " Comics Downloaded"
Why does it keep downloading empty files? Is there any workaround?
The problem here is that the server doesn't serve you the image if your user agent isn't set. Below is a sample code for Python 2.7, which should give you an idea regarding how to make your script work.
import urllib2
import time
first = 1
last = 2622
for i in range(first, last+1):
time.sleep(5) # Be nice to the server! And avoid being blocked.
for ext in ['png', 'gif']:
# Make sure that the img dir exists! If not, the script will throw an
# IOError
with open('img/{}.{}'.format(i, ext), 'wb') as ifile:
try:
req = urllib2.Request('http://www.questionablecontent.net/comics/{}.{}'.format(i, ext))
req.add_header('user-agent', 'Mozilla/5.0')
ifile.write(urllib2.urlopen(req).read())
break
except urllib2.HTTPError:
continue
else:
print 'Could not find image {}'.format(i)
continue
print 'Downloaded image {}'.format(i)
You may want to change your loop into something that resembles your loop (check whether the image has been downloaded previously etc.). This script will try to download all images from <start>.<ext> to <end>.<ext>, where <ext> is either gif or png.