从视频中读取帧时数据包太小

Question

我有一个脚本，它从视频中获取任意数量的帧并将它们保存为图像：这里是代码。

def get_n_frames(n, k, src, dst):
# read n frames from video in src and save them as images on folder dst. If dst does not exists, it is created.
# if n == -1, are saved as many frames as posiible
# k is the number of frames to skip between each pair of frames (ie save only one out of k)

    max_intentos = 10
    end_of_video = 0


    while True:
        cap = cv2.VideoCapture(src)
        if cap.isOpened():
            break
        if max_intentos:
            raise "Capture is not open. There may be a problem with source {}".format(src)
        print("trying again")
        max_intentos -=1

    try:
        i=0
        frame_number = 0 
        while(frame_number < n or n==-1):
            # Capture frame-by-frame
            ret, frame = cap.read()

            if ret:
                end_of_video = 0
                if i % k == 0:

                    final_dest = join(dst, '{0}_{1:03}.jpg'.format(datetime.now().strftime('%Y-%m-%d-%H:%M:%S'), frame_number))
                if cv2.imwrite(final_dest, frame):
                    print("Saving frame {}".format(frame_number))
                    frame_number +=1
                i+=1
            elif end_of_video < 10:
                end_of_video +=1
            else:
                if n != -1:
                    print("WARNING: Video is too short, can not take {} frames with k={}".format(n, k))
                break
    finally:
        # When everything done, release the capture
        cap.release()
        print("{} frames were saved".format(frame_number))

我已经将它用于很多.avi视频，没有问题，但现在我收到一条奇怪的消息：[msvideo1 @ 0x5615d5f85280] Packet is too small我一直在网上搜索，但这似乎很奇怪，这不是一个例外，输出看起来好像程序完成了。

我用.avi视频作为源来调用它，其相对路径为k = 10且n = -1

我不确定这些是视频中的所有帧，更重要的是，这个奇怪的错误是什么？