無法在Python中使用OpenCV編寫視頻

Question

我正在嘗試將實時圖像寫入由Kinect在Ubuntu中獲取的視頻文件中。 請參見下面的示例代碼：

#!/usr/bin/env python
import roslib
roslib.load_manifest('ros_package_name')
import rospy
import cv2
from sensor_msgs.msg import Image
from cv_bridge import CvBridge, CvBridgeError

class image_converter(object):
    def __init__(self, topic_name, file_name, fps=20):
        self.fps = fps
        self.file_name = file_name
        self.bridge = CvBridge()
        self.image_sub = rospy.Subscriber(topic_name, Image, self.callback)
        self.video_writer = None

    def callback(self,data):
        try:
            cv_image = self.bridge.imgmsg_to_cv2(data, 'bgr8')
        except CvBridgeError as e:
            print e

        if self.video_writer is None:
            rows, cols, _ = cv_image.shape
            self.video_writer = cv2.VideoWriter(self.file_name, -1, self.fps, (cols, rows))

        self.video_writer.write(cv_image)

    def clean_shutdown(self):
        if self.video_writer is not None:
            self.video_writer.release()
        print 'Saving video file', self.file_name

    def __del__(self):
        self.clean_shutdown()

def main():
    ic = image_converter('/kinect2/qhd/image_color_rect','video.avi')
    rospy.init_node('save_video', anonymous=True)
    rospy.on_shutdown(ic.clean_shutdown)
    rospy.spin()

該代碼運行正常，並且在終端中未顯示任何錯誤。 但是，即使我使用ctrl+c終止它，它也不會產生任何視頻文件。

Answer 1

使用編解碼器保存視頻。 Motion Jpeg幾乎總是可以工作！

fourcc = cv2.VideoWriter_fourcc(*'MJPG')
self.video_writer = cv2.VideoWriter(file_name, fourcc, fps, frame_size)

然后是故事的其余部分。