如何以高质量录制屏幕

Question

我正在用 python 为桌面创建屏幕录像机。我已经完成了编码部分，但是当我录制屏幕时，为什么它没有以高清录制。 问题......... 1> 我想以高质量记录屏幕我应该怎么做。 2> 我也试图在 cv2.circle() 的帮助下捕捉我的光标，但我想创建不透明度更低或更透明的圆圈

我的代码

import cv2
import numpy as np
import pyautogui
import datetime
import win32api

date=datetime.datetime.now()

SCREEN_SIZE = (960,540) #std res 1366, 768
framerate=12
# define the codec
fourcc = cv2.VideoWriter_fourcc(*'XVID')
filename='E:/project/videos/rec_%s%s%s%s%s%s.avi' %(date.year,date.month,date.day,date.hour,date.minute,date.second)

out = cv2.VideoWriter(filename, fourcc,framerate, SCREEN_SIZE)

while True:

    img = pyautogui.screenshot()

    frame = np.array(img)

    frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
    _xs,_ys = win32api.GetCursorPos()
    image=cv2.circle(frame,(_xs,_ys),20,(0,255,255,0.3),-1)
    frame = cv2.resize(frame,(960,540)) #resize window

    out.write(frame)

    cv2.imshow('screenshot', frame)

    if cv2.waitKey(1) == ord("q"):
        break


cv2.destroyAllWindows()
out.release()

Answer 1

使用cv2.videowriter时，请确保framesize等于屏幕大小，以免图像失真。

另外，如果需要录屏，要确保opencv窗口不影响整个桌面的美观。

在我的代码中，我添加了一个半透明的圆圈。您可以根据需要更改圆圈的透明度。

from PIL import ImageGrab
import numpy as np
import cv2
import datetime
from pynput import keyboard
import threading
import win32api

flag=False 

def transparent_circle(img,center,radius,color,thickness):
    center = tuple(map(int,center))
    rgb = [255*c for c in color[:3]] # convert to 0-255 scale for OpenCV
    alpha = color[-1]
    radius = int(radius)
    if thickness > 0:
        pad = radius + 2 + thickness
    else:
        pad = radius + 3
    roi = slice(center[1]-pad,center[1]+pad),slice(center[0]-pad,center[0]+pad)

    try:
        overlay = img[roi].copy()
        cv2.circle(img,center,radius,rgb, thickness=thickness, lineType=cv2.LINE_AA)
        opacity = alpha
        cv2.addWeighted(src1=img[roi], alpha=opacity, src2=overlay, beta=1. - opacity, gamma=0, dst=img[roi])
    except:
        logger.debug("transparent_circle would have been partially outside of img. Did not draw it.") 

def video_record():
    date=datetime.datetime.now()
    filename='path/rec_%s%s%s%s%s%s.avi' %(date.year,date.month,date.day,date.hour,date.minute,date.second)
    p = ImageGrab.grab()  
    a, b = p.size 
    fourcc = cv2.VideoWriter_fourcc(*'XVID') 
    video = cv2.VideoWriter(filename, fourcc, 20, (a, b)) 
    while True:
        im = ImageGrab.grab()
        imm=cv2.cvtColor(np.array(im), cv2.COLOR_RGB2BGR)
        _xs,_ys = win32api.GetCursorPos()
        transparent_circle(imm,(_xs,_ys),20,(0,255,255,0.5), -1)
#       cv2.circle(imm,(_xs,_ys),20,(0,255,255,0.3),-1)                 
        video.write(imm)
        if flag:
            print("Record Over")
            break
    video.release()
def on_press(key):
    global flag
    if key == keyboard.Key.esc:
        flag=True
        print("stop monitor")
        return False  

if __name__=='__main__':
    th=threading.Thread(target=video_record)
    th.start()
    with keyboard.Listener(on_press=on_press) as listener:
        listener.join()

运行代码时，开始录制。当您按下ESC 键时，停止录制并保存文件。

注意：可能需要添加一些库，否则会出现找不到模块的错误