cv2.VideoWriter_fourcc()

  • 2019 年 10 月 5 日
  • 筆記

版权声明:本文为博主原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接和本声明。

本文链接:https://blog.csdn.net/weixin_36670529/article/details/100977375

#环境:opencv 3.4.0    python 3.5.2    #读取视频    import cv2    cap = cv2.VideoCapture('video.avi')      #读取摄像头,0为摄像头索引,当有多个摄像头时,从0开始编号    cap = cv2.VideoCapture(0)    #从视频或摄像头中读取一帧(即一张图像),返回是否成功标识ret(True代表成功,False代表失败),img为读取的视频帧    ret,frame = cap.read()

#完整的读取视频流并播放视频流代码

# -*- coding:utf-8 -*-    import cv2    cap = cv2.VideoCapture("video.avi")    while(1):    # 读取视频帧        ret, frame = cap.read()    # 显示视频帧        cv2.imshow("capture", frame)    #等候50ms,播放下一帧,或者按q键退出    if cv2.waitKey(50) &0xFF ==ord('q'):        break    #释放视频流    cap.release()    #关闭所有窗口    cv2.destroyAllWindows()

#创建视频流写入对象,VideoWriter_fourcc为视频编解码器,20为帧播放速率,(640,480)为视频帧大小    videoWriter = cv2.VideoWriter('video.avi', cv2.VideoWriter_fourcc('I', '4', '2', '0'), 20, (640,480))    #向视频文件写入一帧    videoWriter.write(frame)    #详解cv2.VideoWriter_fourcc对象(摘自Learning OpenCV3 Computer Vision with Python,坦白讲不太懂)    #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    #以下为写视频的完整代码    #-*-coding:utf-8-*-    import cv2    cap = cv2.VideoCapture('./dataset/video/cap_zhihao.avi')    fps =int(cap.get(cv2.CAP_PROP_FPS))    size = (int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)),    int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)))    videoWriter = cv2.VideoWriter('video.avi', cv2.VideoWriter_fourcc('I','4','2','0'), fps, size)    ret, frame = cap.read()    while(ret):        # 展示一帧        cv2.imshow("capture", frame)        videoWriter.write(frame)        cv2.waitKey(fps)        ret,frame = cap.read()    cap.release()    cv2.destroyAllWindows()