cv2.VideoWriter_fourcc()

  • 2019 年 10 月 5 日
  • 筆記

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本文鏈接:https://blog.csdn.net/weixin_36670529/article/details/100977375

#環境:opencv 3.4.0    python 3.5.2    #讀取影片    import cv2    cap = cv2.VideoCapture('video.avi')      #讀取攝影機,0為攝影機索引,當有多個攝影機時,從0開始編號    cap = cv2.VideoCapture(0)    #從影片或攝影機中讀取一幀(即一張影像),返回是否成功標識ret(True代表成功,False代表失敗),img為讀取的影片幀    ret,frame = cap.read()

#完整的讀取影片流並播放影片流程式碼

# -*- coding:utf-8 -*-    import cv2    cap = cv2.VideoCapture("video.avi")    while(1):    # 讀取影片幀        ret, frame = cap.read()    # 顯示影片幀        cv2.imshow("capture", frame)    #等候50ms,播放下一幀,或者按q鍵退出    if cv2.waitKey(50) &0xFF ==ord('q'):        break    #釋放影片流    cap.release()    #關閉所有窗口    cv2.destroyAllWindows()

#創建影片流寫入對象,VideoWriter_fourcc為影片編解碼器,20為幀播放速率,(640,480)為影片幀大小    videoWriter = cv2.VideoWriter('video.avi', cv2.VideoWriter_fourcc('I', '4', '2', '0'), 20, (640,480))    #向影片文件寫入一幀    videoWriter.write(frame)    #詳解cv2.VideoWriter_fourcc對象(摘自Learning OpenCV3 Computer Vision with Python,坦白講不太懂)    #fourcc意為四字元程式碼(Four-Character Codes),顧名思義,該編碼由四個字元組成,下面是VideoWriter_fourcc對象一些常用的參數,注意:字元順序不能弄混    #cv2.VideoWriter_fourcc('I', '4', '2', '0'),該參數是YUV編碼類型,文件名後綴為.avi    #cv2.VideoWriter_fourcc('P', 'I', 'M', 'I'),該參數是MPEG-1編碼類型,文件名後綴為.avi    #cv2.VideoWriter_fourcc('X', 'V', 'I', 'D'),該參數是MPEG-4編碼類型,文件名後綴為.avi    #cv2.VideoWriter_fourcc('T', 'H', 'E', 'O'),該參數是Ogg Vorbis,文件名後綴為.ogv    #cv2.VideoWriter_fourcc('F', 'L', 'V', '1'),該參數是Flash影片,文件名後綴為.flv    #以下為寫影片的完整程式碼    #-*-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):        # 展示一幀        cv2.imshow("capture", frame)        videoWriter.write(frame)        cv2.waitKey(fps)        ret,frame = cap.read()    cap.release()    cv2.destroyAllWindows()