录制视频按钮在tkinter GUI python

Question

我对python很陌生，尤其是tkinter和opencv。

我已经找到了某种方法(一点方法)来创建一个gui，最终将控制显微镜和人工智能。但是我遇到了一个绊脚石，试图记录在gui中显示的视频，我认为这与已经在显示器中捕获的视频提要有关，但我找不到解决它的方法。这一切都工作得很好，直到我点击记录，然后它崩溃了，我得到错误:打开VIDEOIO(V4L2:/dev/video0):不能通过索引打开相机。

很抱歉这么长的代码，但是我已经尽可能地把它缩短了。

问题出在根。Recbtn和defrec节。

import cv2
import tkinter as tk
import multiprocessing
from tkinter import *
from PIL import Image,ImageTk
from datetime import datetime
from tkinter import messagebox, filedialog
e = multiprocessing.Event()
p = None
# Defining CreateWidgets() function to create necessary tkinter widgets
def createwidgets():
root.cameraLabel = Label(root, bg="gray25", borderwidth=3, relief="ridge")
root.cameraLabel.grid(row=2, column=1, padx=10, pady=10, columnspan=3)
root.browseButton = Button(root, bg="gray25", width=10, text="BROWSE", command=destBrowse)
root.browseButton.grid(row=1, column=1, padx=10, pady=10)
root.recbtn = Button(root, bg="gray25", width=10, text="Record", command=rec)
root.recbtn.grid(row=1, column=5, padx=10, pady=10)
root.saveLocationEntry = Entry(root, width=55, textvariable=destPath)
root.saveLocationEntry.grid(row=1, column=2, padx=10, pady=10)
# Calling ShowFeed() function
ShowFeed()
# Defining ShowFeed() function to display webcam feed in the cameraLabel;
def ShowFeed():
# t5  # Capturing frame by frame
ret, frame = root.cap.read()
if ret:
# Flipping the frame vertically
frame = cv2.flip(frame, 1)
# Changing the frame color from BGR to RGB
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
# Creating an image memory from the above frame exporting array interface
videoImg = Image.fromarray(cv2image)
# Creating object of PhotoImage() class to display the frame
imgtk = ImageTk.PhotoImage(image = videoImg)
# Configuring the label to display the frame
root.cameraLabel.configure(image=imgtk)
# Keeping a reference
root.cameraLabel.imgtk = imgtk
# Calling the function after 10 milliseconds
root.cameraLabel.after(10, ShowFeed)
else:
# Configuring the label to display the frame
root.cameraLabel.configure(image='')
def destBrowse():
# Presenting user with a pop-up for directory selection. initialdir argument is optional
# Retrieving the user-input destination directory and storing it in destinationDirectory
# Setting the initialdir argument is optional. SET IT TO YOUR DIRECTORY PATH
destDirectory = filedialog.askdirectory(initialdir="YOUR DIRECTORY PATH")
# Displaying the directory in the directory textbox
destPath.set(destDirectory)
def rec():
vid_name = datetime.now().strftime('%d-%m-%Y %H-%M-%S')
# If the user has selected the destination directory, then get the directory and save it in image_path
if destPath.get() != '':
vid_path = destPath.get()
# If the user has not selected any destination directory, then set the image_path to default directory
else:
messagebox.showerror("ERROR", "No Directory Selected!")
# Concatenating the image_path with image_name and with .jpg extension and saving it in imgName variable
vidName = vid_path + '/' + vid_name + ".avi"
capture = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc('X', 'V', 'I', 'D')
videoWriter = cv2.VideoWriter(vidName, fourcc, 30.0, (640, 480))
while (True):
ret, frame = capture.read()
if ret:
cv2.imshow('video', frame)
videoWriter.write(frame)
if cv2.waitKey(1) == 27:
break
capture.release()
videoWriter.release()
# Creating object of tk class
root = tk.Tk()
# Creating object of class VideoCapture with webcam index
root.cap = cv2.VideoCapture(0)
# Setting width and height
width, height = 1200, 1200
root.cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)
root.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)
# Setting the title, window size, background color and disabling the resizing property
root.title("Test-AI-tes")
root.geometry("1600x1024")
root.resizable(True, True)
root.configure(background = "gray18")
# Creating tkinter variables
destPath = StringVar()
imagePath = StringVar()
createwidgets()
root.mainloop()

谢谢!

Answer 1

这个答案类似于@Art的答案，但我删除了after_id和queue。

import cv2
import threading
import tkinter as tk
from PIL import Image, ImageTk

def stop_rec():
global running
running = False
start_button.config(state="normal")
stop_button.config(state="disabled")
def start_capture():
global capture, last_frame
capture = cv2.VideoCapture(0)

fourcc = cv2.VideoWriter_fourcc("X", "V", "I", "D")
video_writer = cv2.VideoWriter(r"sample.avi", fourcc, 30.0, (640, 480))
while running:
rect, frame =  capture.read()
if rect:
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
last_frame = Image.fromarray(cv2image)
video_writer.write(frame)
capture.release()
video_writer.release()
def update_frame():
if last_frame is not None:
tk_img = ImageTk.PhotoImage(master=video_label, image=last_frame)
video_label.config(image=tk_img)
video_label.tk_img = tk_img
if running:
root.after(10, update_frame)
def start_rec():
global running
running = True
thread = threading.Thread(target=start_capture, daemon=True)
thread.start()
update_frame()
start_button.config(state="disabled")
stop_button.config(state="normal")
def closeWindow():
stop_rec()
root.destroy()

running = False
after_id = None
last_frame = None
root = tk.Tk()
root.protocol("WM_DELETE_WINDOW", closeWindow)
video_label = tk.Label()
video_label.pack(expand=True, fill="both")
start_button = tk.Button(text="Start", command=start_rec)
start_button.pack()
stop_button = tk.Button(text="Stop", command=stop_rec, state="disabled")
stop_button.pack()
root.mainloop()

使用布尔标志running代替after_id。此外，而不是将图像存储在队列中，然后显示它，我只保留最后一个图像。这样它就可以在我的电脑上实时运行。别担心，所有的帧仍然被存储在视频文件中。

Answer 2

在GUI的循环中不能有无限while循环。当你有一个IO操作要完成时，你应该使用线程。

示例代码:

import cv2
import threading
import tkinter as tk
from PIL import Image, ImageTk
from queue import Queue
def stop_rec():
global running, after_id
running = False
if after_id:
root.after_cancel(after_id)
after_id = None

with frame_queue.mutex:
frame_queue.queue.clear()
def start_capture():
global capture
capture = cv2.VideoCapture(0)

fourcc = cv2.VideoWriter_fourcc('X', 'V', 'I', 'D')
video_writer = cv2.VideoWriter(r"sample.avi", fourcc, 30.0, (640, 480))
while running:

rect, frame =  capture.read()
if rect:
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
videoImg = Image.fromarray(cv2image)
# current_frame = ImageTk.PhotoImage(image = videoImg)
frame_queue.put(videoImg)
video_writer.write(frame)

capture.release()
video_writer.release()
def update_frame():
global after_id
if not frame_queue.empty():
video_label.image_frame = ImageTk.PhotoImage(frame_queue.get_nowait())
video_label.config(image=video_label.image_frame)

after_id = root.after(10, update_frame)
def start_rec():
global running
stop_rec()
running = True
thread = threading.Thread(target=start_capture, daemon=True)
thread.start()
update_frame()

def closeWindow():
stop_rec()
root.destroy()

running = False
after_id = None
frame_queue = Queue()
root = tk.Tk()
root.protocol("WM_DELETE_WINDOW", closeWindow)
video_label = tk.Label()
video_label.pack(expand=True, fill="both")
tk.Button(text="Start", command=start_rec).pack()
tk.Button(text="stop", command=stop_rec).pack()
root.mainloop()

快速解释:

• 在新线程中启动记录功能。
• 使用Queue来存储帧。
• 然后使用[widget].after定期更新标签。
• 使用[widget].after_cancel(after_id)方法停止录音(使用.after方法时返回after_id)，设置运行变量为False停止循环。