无法在Python中通过opencv编写视频

Question

我是一个开放的简历初学者.我按照本教程中的步骤练习使用它. http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_gui/py_video_display/py_video_display.html#display-video

我在mac上更改了一些性能线:

import numpy as np
import cv2

cap = cv2.VideoCapture(0)
size = (int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH)),
        int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT)))

# Define the codec and create VideoWriter object
fourcc = cv2.cv.CV_FOURCC(*'DIVX') # upper case - yl3
out = cv2.VideoWriter('output.avi',fourcc, 20, size, 1) #20.0: number of frames per sec

while(cap.isOpened()):
    ret, frame = cap.read()
    if ret==True:
        frame = cv2.flip(frame,1)

        # write the flipped frame
        out.write(frame)

        cv2.imshow('frame',frame)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()

我正在使用Python 2.7.10,opencv 2.4.12和mac OS X 10.10.5现在我可以成功地让相机工作并output.avi在同一目录中生成一个文件,但文件只有414k加班,我无法打开它.它似乎只包含黑色.

任何人都可以帮助我吗？

Answer 1

所以我遇到了和你一样的问题.我把它缩小到了它的值cv2.cv.CV_FOURCC.这些显然是区分大小写的.我无法让.avi编解码器工作,但如果你不介意MPEG,这对我有用.

import numpy as np
import cv2

cap = cv2.VideoCapture(0)
size = (int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_WIDTH)),
        int(cap.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT)))

fps = 20
fourcc = cv2.cv.CV_FOURCC('m', 'p', '4', 'v') # note the lower case
vout = cv2.VideoWriter()
success = vout.open('output.mp4',fourcc,fps,size,True) 
while True:
    ret, frame = cap.read()
    if not ret:
        break

    frame = cv2.flip(frame, -1)

    vout.write(frame) 

    cv2.imshow('frame', frame)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
vout.release()
cv2.destroyAllWindows()