前言
工作中遇到域控中无中间件，无法采用rosbag等中间件的形式同时采集感知结果与视频流，只能通过外接摄像头采集视频流，以及使用can报文或者bin文件形式存储路测数据；导致本地回放时，无法通过视频流观察真实情况，来判断优化方向。于是，另辟蹊径，将工程代码转成ros方式以及将视频流转成rosbag，可同时使用rviz分析算法与image定位问题；
注意事项
1.需要使用python2
代码
import time, sys, os
from ros import rosbag
import roslib, rospy
roslib.load_manifest('sensor_msgs')
from sensor_msgs.msg import Image
import argparse
from cv_bridge import CvBridge
import cv2TOPIC = "/image_viz" # 对应topic_name
def CreateVideoBag(videopath, bagname):'''Creates a bag file with a video file'''print("raw mp4 name:",videopath)print("output bag name:",bagname)bag = rosbag.Bag(bagname, 'w')cap = cv2.VideoCapture(videopath)cb = CvBridge()prop_fps = cap.get(cv2.CAP_PROP_FPS) if prop_fps != prop_fps or prop_fps <= 1e-2:print("Warning: can't get FPS. Assuming 24.")prop_fps = 24prop_fps = 24 # print("set fps:",prop_fps)ret = Trueframe_id = 0while(ret):ret, frame = cap.read()if not ret:breakstamp = rospy.rostime.Time.from_sec(float(frame_id) / prop_fps)frame_id += 1image = cb.cv2_to_imgmsg(frame, encoding='bgr8')image.header.stamp = stampimage.header.frame_id = "base_link"bag.write(TOPIC, image, stamp)cap.release()bag.close()if __name__ == "__main__":# parser = argparse.ArgumentParser()# parser.add_argument("--topic", type=str, default="/image_viz")# args = parser.parse_args()if len( sys.argv ) == 3:CreateVideoBag(*sys.argv[1:])else:print( "Usage: video2bag videofilename bagfilename")步骤
python2 mp4_to_bag.py <video_name>.mp4 <output_bag_name>.bag # 执行转化命令
rosbag play -l <output_bag_name>.bag camera/image_raw:=image_raw0 # 循环播放图片，并重命名成自己需要的话题名
结果
PS：请注意视频流与算法处理存在些许的时间差。
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