我想从YouTube读取实时流以执行一些基本的计算机视觉操作,可能需要将YouTube URL 转换为OpenCV可读取的格式,例如:
cap = cv2.VideoCapture('https://www.youtube.com/watch?v=_9OBhtLA9Ig')
有人做过吗?
我相信您已经知道答案了,但我会为其他搜索相同主题的人回答。您可以使用 Pafy 来完成此操作。
(可能需要与 youtube_dl 一起使用)。
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()
# ...
就是这样了。
# 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()
RuntimeError: [CamGear:ERROR] :: 源无效,CamGear无法初始化此源上的流!
- Mr Purple在获得100-120帧后,@lee hannigan的答案使我的YouTube直播流崩溃了。
我使用Pafy想出了一个方法,只获取x个帧并将它们拼接在一起。然而,这最终拼凑出结果很差,并且结果不连贯。也许Pafy不适用于直播流,我找不到无缝拼接帧的方法。
最终有效的方法稍有修改,来自guttentag_liu在此篇文章中的回答。需要安装几个软件包,代码有点冗长,但是可行。因为文件是直播的,所以需要分块保存在临时文件中。您可以在每个块上进行openCV处理,然后最后保存到文件而不是重新打开。
# 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://dev59.com/1XI95IYBdhLWcg3w8iv1
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)
urllib
,请参阅此页面。 - Jeru Luke