Question

我是python的初学者，也是opencv的初学者。我想用opencv视频捕捉功能拍摄一段时间的视频，比如10秒然后系统应该进入睡眠模式一段时间让我们说6秒。然后它需要10秒的视频。两个视频应该保存在单独的文件中。我的问题是，当我调用第一个功能时它会保存第一个视频但是在调用video2功能时它不会保存视频，因为代码排列不当。我是新用户。

import cv2
import time
def delay(delay_time):
     timeout = delay_time   # [seconds]

     timeout_start = time.time()

     print(time.strftime("%c"))
    while time.time() < timeout_start + timeout:
          test = 0
          if test == 3:

             break
          test -= 1
     print(time.strftime("%c"))

def video1():



   cap = cv2.VideoCapture(0)


   if (cap.isOpened() == False):
   print("Unable to read camera feed")

    frame_width = int(cap.get(3))
    frame_height = int(cap.get(4))

    out = cv2.VideoWriter('Data/output1.avi', 
    cv2.VideoWriter_fourcc('M', 'J', 'P', 'G'), 10, (frame_width, frame_height))

   while time.time() < time_start + closing_time:
         ret, frame = cap.read()

         if ret == True:
        out.write(frame)

           cv2.imshow('frame', frame)

            if cv2.waitKey(1) & 0xFF == ord('q'):
                break

            else:
                break

   cap.release()
   out.release()

def video2():


   cap = cv2.VideoCapture(0)

   if (cap.isOpened() == False):
   print("Unable to read camera feed")

    frame_width = int(cap.get(3))
    frame_height = int(cap.get(4))

    out = cv2.VideoWriter('Data/output2.avi', 
    cv2.VideoWriter_fourcc('M', 'J', 'P', 'G'), 10, (frame_width, frame_height))

   while time.time() < time_start + closing_time:
         ret, frame = cap.read()

         if ret == True:

            out.write(frame)

           cv2.imshow('frame', frame)

            if cv2.waitKey(1) & 0xFF == ord('q'):
                break

            else:
                break

   cap.release()
   out.release()

   cv2.destroyAllWindows()


   cv2.destroyAllWindows()
   print(time.strftime("%c"))
   video1()
   delay(6)
   print(time.strftime("%c"))
   video2()

Answer 1

您的代码有很多缩进问题，我甚至无法指向1个位置，并说这是一个问题。所以我在这里重新安排了你的代码。您甚至没有在代码中定义time_start或closing_time。但我假设你的真实代码有它们，而问题只是第二个输出不正确的视频。那是因为您必须在time_start和video1的开头定义video2。如果您没有重新定义time_start，那么当您video2 while time.time() < time_start + closing_time:时，此import cv2 import time def delay(delay_time): timeout = delay_time # [seconds] timeout_start = time.time() print(time.strftime("%c")) while time.time() < timeout_start + timeout: test = 0 if test == 3: break test -= 1 print(time.strftime("%c")) def video1(): time_start = time.time() cap = cv2.VideoCapture(0) if (cap.isOpened() == False): print("Unable to read camera feed") frame_width = int(cap.get(3)) frame_height = int(cap.get(4)) print(frame_width,frame_height) out = cv2.VideoWriter('output1.avi', cv2.VideoWriter_fourcc('M', 'J', 'P', 'G'), 10, (frame_width, frame_height)) while time.time() < time_start + closing_time: ret, frame = cap.read() if ret == True: out.write(frame) #cv2.imshow('frame', frame) if cv2.waitKey(1) & 0xFF == ord('q'): break else: break cap.release() out.release() def video2(): time_start = time.time() cap = cv2.VideoCapture(0) if (cap.isOpened() == False): print("Unable to read camera feed") frame_width = int(cap.get(3)) frame_height = int(cap.get(4)) print(frame_width,frame_height) out = cv2.VideoWriter('output2.avi', cv2.VideoWriter_fourcc('M', 'J', 'P', 'G'), 10, (frame_width, frame_height)) while time.time() < time_start + closing_time: ret, frame = cap.read() if ret == True: out.write(frame) if cv2.waitKey(1) & 0xFF == ord('q'): break else: break cap.release() out.release() print(time.strftime("%c")) closing_time = 10 video1() delay(6) print(time.strftime("%c")) video2() # this loop is here because sometimes cv2 has problems destroying windows # if you call it once. so to be safe I call it 10 times for _ in range(10): cv2.destroyAllWindows()已经用尽且将为假。因此没有真正的视频写入文件。

colorStand <- colorRampPalette(colors = c("blue", "white", "red"))

heatmaply(data, margins = c(60,100,40,20), colors=colorStand,
    limits = c(-2.5,2.5),showticklabels = c(T,F))

Answer 2

这应该可以解决你在问题中提出的问题，代码如下： `

import cv2
import time
import numpy as np
cap=cv2.VideoCapture(0)
fourcc=cv2.VideoWriter_fourcc(*'XVID')
out=cv2.VideoWriter('output1.avi', fourcc, 20.0, (640, 48))
start_time=time.time()
while True:
    ret, frame=cap.read()
    out.write(frame)
    cv2.imshow('frame', frame)
    if time.time()-start_time>=10:
        break
cap.release()
out.release()
time.sleep(6)
cap2=cv2.VideoCapture(0)
fourcc2=cv2.VideoWriter_fourcc(*'XVID')
out2=cv2.VideoWriter('output2.avi', fourcc2, 20.0, (640, 48))
start_time2=time.time()
while True:
    ret, frame=cap2.read()
    out2.write(frame)
    cv2.imshow('frame', frame)
    if time.time()-start_time2>=10:
        break
cap2.release()
out.release()

`

在一段时间后使用opencv拍摄视频

2 个答案: