Question

我想创建一个网络摄像头流媒体应用，记录网络摄像头流，比如大约30秒，然后保存为myFile.wmv。现在要获得实时相机输入，我知道这段代码： -

import cv2
import numpy as np
c = cv2.VideoCapture(0)

while(1):
    _,f = c.read()
    cv2.imshow('e2',f)
    if cv2.waitKey(5)==27:
        break
cv2.destroyAllWindows()

但我不知道如何记录给定的秒数并将其保存为当前目录中的文件，

请有人指出我正确的方向

由于

Answer 1

关于时间

为什么不使用python time function？特别是time.time()请查看此answer about time in python

NB OpenCV应该拥有（或拥有）自己的计时器，但我无法确定它是否适用于当前版本。

关于录制/保存

看看这个other answer

Answer 2

OpenCV 允许您录制视频，但不能录制音频。我从 JRodrigoF 遇到了这个脚本，它使用 openCV 录制视频，使用 pyaudio 录制音频。我在一个类似的项目中使用了一段时间；但是，我注意到有时线程会挂起并导致程序崩溃。另一个问题是 openCV 无法以可靠的速率捕获视频帧，并且 ffmpeg 在重新编码时会扭曲视频。

https://github.com/JRodrigoF/AVrecordeR

我想出了一个新的解决方案，它的记录更可靠、质量更高。它目前仅适用于 Windows，因为它使用 pywinauto 和内置的 Windows 相机应用程序。脚本的最后一点会进行一些错误检查，通过检查视频名称的时间戳来确认视频录制成功。

https://gist.github.com/mjdargen/956cc968864f38bfc4e20c9798c7d670

import pywinauto
import time
import subprocess
import os
import datetime

def win_record(duration):
    subprocess.run('start microsoft.windows.camera:', shell=True)  # open camera app

    # focus window by getting handle using title and class name
    # subprocess call opens camera and gets focus, but this provides alternate way
    # t, c = 'Camera', 'ApplicationFrameWindow'
    # handle = pywinauto.findwindows.find_windows(title=t, class_name=c)[0]
    # # get app and window
    # app = pywinauto.application.Application().connect(handle=handle)
    # window = app.window(handle=handle)
    # window.set_focus()  # set focus
    time.sleep(2)  # have to sleep

    # take control of camera window to take video
    desktop = pywinauto.Desktop(backend="uia")
    cam = desktop['Camera']
    # cam.print_control_identifiers()
    # make sure in video mode
    if cam.child_window(title="Switch to Video mode", auto_id="CaptureButton_1", control_type="Button").exists():
        cam.child_window(title="Switch to Video mode", auto_id="CaptureButton_1", control_type="Button").click()
    time.sleep(1)
    # start then stop video
    cam.child_window(title="Take Video", auto_id="CaptureButton_1", control_type="Button").click()
    time.sleep(duration+2)
    cam.child_window(title="Stop taking Video", auto_id="CaptureButton_1", control_type="Button").click()

    # retrieve vids from camera roll and sort
    dir = 'C:/Users/michael.dargenio/Pictures/Camera Roll'
    all_contents = list(os.listdir(dir))
    vids = [f for f in all_contents if "_Pro.mp4" in f]
    vids.sort()
    vid = vids[-1]
    # compute time difference
    vid_time = vid.replace('WIN_', '').replace('_Pro.mp4', '')
    vid_time = datetime.datetime.strptime(vid_time, '%Y%m%d_%H_%M_%S')
    now = datetime.datetime.now()
    diff = now - vid_time
    # time different greater than 2 minutes, assume something wrong & quit
    if diff.seconds > 120:
        quit()
    
    subprocess.run('Taskkill /IM WindowsCamera.exe /F', shell=True)  # close camera app
    print('Recorded successfully!')


win_record(2)

Python网络摄像头记录

2 个答案: