1.保存图像数据
使用 image_view image_saver
打开一个终端输入以下指令
rosrun image_view image_saver image:=/usb_cam/image_raw _filename_format:= "%04i.png" _encoding:=bgr8
参数分别为：图像的topic、文件名（%04i是指4位数的数字）、文件的编码 32FC1和bgr8
然后再起一个终端播放需要保持的图像数据对应的bag文件。
注意：png文件保存的路径为终端的当前路径。
2.pcd保存
激光雷达数据保存为pcd格式
使用 pcl_ros bag_to_pcd
参数分别为：rosbag的位置、激光雷达topic、保存到哪个文件夹
rosrun pcl_ros bag_to_pcd BAG_DIR /velodyne_points SAVE_DIR
BAG_DIR 为bag路径。 SAVE_DIR为保存路径
3.保存mp4文件
安装依赖：
sudo apt install ffmpeg
将 rosbag2video.py文件与bag文件放在同一路径下
运行python脚本
python rosbag2video.py test.bag
rosbag2video.py 源码
#!/usr/bin/env python3
"""
rosbag2video.py
rosbag to video file conversion tool
by Abel Gabor 2019
baquatelle@gmail.com
requirements:
sudo apt install python3-roslib python3-sensor-msgs python3-opencv ffmpeg
based on the tool by Maximilian Laiacker 2016
post@mlaiacker.de"""
import roslib
#roslib.load_manifest('rosbag')
import rospy
import rosbag
import sys, getopt
import os
from sensor_msgs.msg import CompressedImage
from sensor_msgs.msg import Image
import cv2
import numpy as np
import shlex, subprocess
MJPEG_VIDEO = 1
RAWIMAGE_VIDEO = 2
VIDEO_CONVERTER_TO_USE = "ffmpeg" # or you may want to use "avconv"
def print_help():
print('rosbag2video.py [--fps 25] [--rate 1] [-o outputfile] [-v] [-s] [-t topic] bagfile1 [bagfile2] ...')
print()
print('Converts image sequence(s) in ros bag file(s) to video file(s) with fixed frame rate using',VIDEO_CONVERTER_TO_USE)
print(VIDEO_CONVERTER_TO_USE,'needs to be installed!')
print()
print('--fps Sets FPS value that is passed to',VIDEO_CONVERTER_TO_USE)
print(' Default is 25.')
print('-h Displays this help.')
print('--ofile (-o) sets output file name.')
print(' If no output file name (-o) is given the filename \'<prefix><topic>.mp4\' is used and default output codec is h264.')
print(' Multiple image topics are supported only when -o option is _not_ used.')
print(' ',VIDEO_CONVERTER_TO_USE,' will guess the format according to given extension.')
print(' Compressed and raw image messages are supported with mono8 and bgr8/rgb8/bggr8/rggb8 formats.')
print('--rate (-r) You may slow down or speed up the video.')
print(' Default is 1.0, that keeps the original speed.')
print('-s Shows each and every image extracted from the rosbag file (cv_bride is needed).')
print('--topic (-t) Only the images from topic "topic" are used for the video output.')
print('-v Verbose messages are displayed.')
print('--prefix (-p) set a output file name prefix othervise \'bagfile1\' is used (if -o is not set).')
print('--start Optional start time in seconds.')
print('--end Optional end time in seconds.')
class RosVideoWriter():
def __init__(self, fps=25.0, rate=1.0, topic="", output_filename ="", display= False, verbose = False, start = rospy.Time(0), end = rospy.Time(sys.maxsize)):
self.opt_topic = topic
self.opt_out_file = output_filename
self.opt_verbose = verbose
self.opt_display_images = display
self.opt_start = start
self.opt_end = end
self.rate = rate
self.fps = fps
self.opt_prefix= None
self.t_first={}
self.t_file={}
self.t_video={}
self.p_avconv = {}
def parseArgs(self, args):
opts, opt_files = getopt.getopt(args,"hsvr:o:t:p:",["fps=","rate=","ofile=","topic=","start=","end=","prefix="])
for opt, arg in opts:
if opt == '-h':
print_help()
sys.exit(0)
elif opt == '-s':
self.opt_display_images = True
elif opt == '-v':
self.opt_verbose = True
elif opt in ("--fps"):
self.fps = float(arg)
elif opt in ("-r", "--rate"):
self.rate = float(arg)
elif opt in ("-o", "--ofile"):
self.opt_out_file = arg
elif opt in ("-t", "--topic"):
self.opt_topic = arg
elif opt in ("-p", "--prefix"):
self.opt_prefix = arg
elif opt in ("--start"):
self.opt_start = rospy.Time(int(arg))
if(self.opt_verbose):
print("starting at",self.opt_start.to_sec())
elif opt in ("--end"):
self.opt_end = rospy.Time(int(arg))
if(self.opt_verbose):
print("ending at",self.opt_end.to_sec())
else:
print("opz:", opt,'arg:', arg)
if (self.fps<=0):
print("invalid fps", self.fps)
self.fps = 1
if (self.rate<=0):
print("invalid rate", self.rate)
self.rate = 1
if(self.opt_verbose):
print("using ",self.fps," FPS")
return opt_files
# filter messages using type or only the opic we whant from the 'topic' argument
def filter_image_msgs(self, topic, datatype, md5sum, msg_def, header):
if(datatype=="sensor_msgs/CompressedImage"):
if (self.opt_topic != "" and self.opt_topic == topic) or self.opt_topic == "":
print("############# COMPRESSED IMAGE ######################")
print(topic,' with datatype:', str(datatype))
print()
return True;
if(datatype=="theora_image_transport/Packet"):
if (self.opt_topic != "" and self.opt_topic == topic) or self.opt_topic == "":
print(topic,' with datatype:', str(datatype))
print('!!! theora is not supported, sorry !!!')
return False;
if(datatype=="sensor_msgs/Image"):
if (self.opt_topic != "" and self.opt_topic == topic) or self.opt_topic == "":
print("############# UNCOMPRESSED IMAGE ######################")
print(topic,' with datatype:', str(datatype))
print()
return True;
return False;
def write_output_video(self, msg, topic, t, video_fmt, pix_fmt = ""):
# no data in this topic
if len(msg.data) == 0 :
return
# initiate data for this topic
if not topic in self.t_first :
self.t_first[topic] = t # timestamp of first image for this topic
self.t_video[topic] = 0
self.t_file[topic] = 0
# if multiple streams of images will start at different times the resulting video files will not be in sync
# current offset time we are in the bag file
self.t_file[topic] = (t-self.t_first[topic]).to_sec()
# fill video file up with images until we reache the current offset from the beginning of the bag file
while self.t_video[topic] < self.t_file[topic]/self.rate :
if not topic in self.p_avconv:
# we have to start a new process for this topic
if self.opt_verbose :
print("Initializing pipe for topic", topic, "at time", t.to_sec())
if self.opt_out_file=="":
out_file = self.opt_prefix + str(topic).replace("/", "_")+".mp4"
else:
out_file = self.opt_out_file
if self.opt_verbose :
print("Using output file ", out_file, " for topic ", topic, ".")
if video_fmt == MJPEG_VIDEO :
cmd = [VIDEO_CONVERTER_TO_USE, '-v', '1', '-stats', '-r',str(self.fps),'-c','mjpeg','-f','mjpeg','-i','-','-an',out_file]
self.p_avconv[topic] = subprocess.Popen(cmd, stdin=subprocess.PIPE)
if self.opt_verbose :
print("Using command line:")
print(cmd)
elif video_fmt == RAWIMAGE_VIDEO :
size = str(msg.width)+"x"+str(msg.height)
cmd = [VIDEO_CONVERTER_TO_USE, '-v', '1', '-stats','-r',str(self.fps),'-f','rawvideo','-s',size,'-pix_fmt', pix_fmt,'-i','-','-an',out_file]
self.p_avconv[topic] = subprocess.Popen(cmd, stdin=subprocess.PIPE)
if self.opt_verbose :
print("Using command line:")
print(cmd)
else :
print("Script error, unknown value for argument video_fmt in function write_output_video.")
exit(1)
# send data to ffmpeg process pipe
self.p_avconv[topic].stdin.write(msg.data)
# next frame time
self.t_video[topic] += 1.0/self.fps
def addBag(self, filename):
if self.opt_display_images:
from cv_bridge import CvBridge, CvBridgeError
bridge = CvBridge()
cv_image = []
if self.opt_verbose :
print("Bagfile: {}".format(filename))
if not self.opt_prefix:
# create the output in the same folder and name as the bag file minu '.bag'
self.opt_prefix = bagfile[:-4]
#Go through the bag file
bag = rosbag.Bag(filename)
if self.opt_verbose :
print("Bag opened.")
# loop over all topics
for topic, msg, t in bag.read_messages(connection_filter=self.filter_image_msgs, start_time=self.opt_start, end_time=self.opt_end):
try:
if msg.format.find("jpeg")!=-1 :
if msg.format.find("8")!=-1 and (msg.format.find("rgb")!=-1 or msg.format.find("bgr")!=-1 or msg.format.find("bgra")!=-1 ):
if self.opt_display_images:
np_arr = np.fromstring(msg.data, np.uint8)
cv_image = cv2.imdecode(np_arr, cv2.CV_LOAD_IMAGE_COLOR)
self.write_output_video( msg, topic, t, MJPEG_VIDEO )
elif msg.format.find("mono8")!=-1 :
if self.opt_display_images:
np_arr = np.fromstring(msg.data, np.uint8)
cv_image = cv2.imdecode(np_arr, cv2.CV_LOAD_IMAGE_COLOR)
self.write_output_video( msg, topic, t, MJPEG_VIDEO )
elif msg.format.find("16UC1")!=-1 :
if self.opt_display_images:
np_arr = np.fromstring(msg.data, np.uint16)
cv_image = cv2.imdecode(np_arr, cv2.CV_LOAD_IMAGE_COLOR)
self.write_output_video( msg, topic, t, MJPEG_VIDEO )
else:
print('unsupported jpeg format:', msg.format, '.', topic)
# has no attribute 'format'
except AttributeError:
try:
pix_fmt=None
if msg.encoding.find("mono8")!=-1 or msg.encoding.find("8UC1")!=-1:
pix_fmt = "gray"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bgr8")
elif msg.encoding.find("bgra")!=-1 :
pix_fmt = "bgra"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bgr8")
elif msg.encoding.find("bgr8")!=-1 :
pix_fmt = "bgr24"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bgr8")
elif msg.encoding.find("bggr8")!=-1 :
pix_fmt = "bayer_bggr8"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bayer_bggr8")
elif msg.encoding.find("rggb8")!=-1 :
pix_fmt = "bayer_rggb8"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bayer_rggb8")
elif msg.encoding.find("rgb8")!=-1 :
pix_fmt = "rgb24"
if self.opt_display_images:
cv_image = bridge.imgmsg_to_cv2(msg, "bgr8")
elif msg.encoding.find("16UC1")!=-1 :
pix_fmt = "gray16le"
else:
print('unsupported encoding:', msg.encoding, topic)
#exit(1)
if pix_fmt:
self.write_output_video( msg, topic, t, RAWIMAGE_VIDEO, pix_fmt )
except AttributeError:
# maybe theora packet
# theora not supported
if self.opt_verbose :
print("Could not handle this format. Maybe thoera packet? theora is not supported.")
pass
if self.opt_display_images:
cv2.imshow(topic, cv_image)
key=cv2.waitKey(1)
if key==1048603:
exit(1)
if self.p_avconv == {}:
print("No image topics found in bag:", filename)
bag.close()
if __name__ == '__main__':
#print()
#print('rosbag2video, by Maximilian Laiacker 2020 and Abel Gabor 2019')
#print()
if len(sys.argv) < 2:
print('Please specify ros bag file(s)!')
print_help()
sys.exit(1)
else :
videowriter = RosVideoWriter()
try:
opt_files = videowriter.parseArgs(sys.argv[1:])
except getopt.GetoptError:
print_help()
sys.exit(2)
# loop over all files
for files in range(0,len(opt_files)):
#First arg is the bag to look at
bagfile = opt_files[files]
videowriter.addBag(bagfile)
print("finished")
4. mp4 视频转ros消息
将视频转成ROS格式 .bag格式包 python实现_轮子去哪儿了的博客-CSDN博客_如果将视频转为bag
参考链接：
rosbag保存 pcd和image_rosbag 保存图像_hhz_999的博客-CSDN博客文章来源：https://www.toymoban.com/news/detail-798702.html
【ROS学习】 rosbag 转化为 mp4 格式视频_wongHome的博客-CSDN博客_mp4转rosbag文章来源地址https://www.toymoban.com/news/detail-798702.html
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