OpenCV学习笔记

向右看齐 2023-01-11 09:05 202阅读 0赞

"""
    参数1 即将保存的文件路径
    参数2 VideoWriter_fourcc为视频编解码器
        fourcc意为四字符代码（Four-Character Codes），顾名思义，该编码由四个字符组成,下面是VideoWriter_fourcc对象一些常用的参数,注意：字符顺序不能弄混
        cv2.VideoWriter_fourcc('I', '4', '2', '0'),该参数是YUV编码类型，文件名后缀为.avi 
        cv2.VideoWriter_fourcc('P', 'I', 'M', 'I'),该参数是MPEG-1编码类型，文件名后缀为.avi 
        cv2.VideoWriter_fourcc('X', 'V', 'I', 'D'),该参数是MPEG-4编码类型，文件名后缀为.avi 
        cv2.VideoWriter_fourcc('T', 'H', 'E', 'O'),该参数是Ogg Vorbis,文件名后缀为.ogv 
        cv2.VideoWriter_fourcc('F', 'L', 'V', '1'),该参数是Flash视频，文件名后缀为.flv
        cv2.VideoWriter_fourcc('m', 'p', '4', 'v')    文件名后缀为.mp4
    参数3 为帧播放速率
    参数4 (width,height)为视频帧大小

import cv2
    cap = cv2.VideoCapture(0)
    fourcc = cv2.VideoWriter_fourcc('F', 'L', 'V', '1')
    out = cv2.VideoWriter('a.flv',fourcc,20.0,(640,480))
    while(cap.isOpened()):
        ret,frame = cap.read()
        if ret==True:
            out.write(frame)
            cv2.imshow('frame',frame)
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
        else:
            break
    out.release()
    cap.release()
    cv2.destroyAllWindows()

import numpy as np
    import cv2
    cap = cv2.VideoCapture('anew.flv')
    fourcc = cv2.VideoWriter_fourcc('M','J','P','G')
    fps = cap.get(cv2.CAP_PROP_FPS)
    print(fps)
    #视频图像的宽度
    frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    print(frame_width)
    print(frame_height)
    out = cv2.VideoWriter('hopenow.avi',fourcc,fps,(frame_width,frame_height))
    while(True):
        ret,frame = cap.read()
        if ret == True:
            frame = cv2.flip(frame,1)
            out.write(frame)
            cv2.imshow('frame',frame)
            if cv2.waitKey(25) & 0xff == ord('q'):
                break
        else:
            break
    out.release()
    cap.release()
    cv2.destroyAllWindows()