ROS bag文件处理之从bag文件中提取图片并合成视频
API以及环境依赖
原理是使用rosbag api，从bag文件中过滤出sensor_msgs/CompressedImage类型的数据，对每一帧压缩图片使用ffmpeg进行编码，所以需要使用ffmpeg，如果未安装ffmpeg，可使用如下命令进行安装：
sudo apt-get install ffmpeg
脚本依赖还有opencv，可使用如下命令进行安装：
pip3 install opencv-python
安装opencv可能会出现一些问题，可参考我另外一篇博客
完整代码
# !/usr/bin/env python3
# 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
ros_path = '/opt/ros/kinetic/lib/python2.7/dist-packages'
if ros_path in sys.path:
sys.path.remove(ros_path)
import cv2
import numpy as np
import subprocess
sys.path.append('/opt/ros/kinetic/lib/python2.7/dist-packages')
MJPEG_VIDEO = 1
RAWIMAGE_VIDEO = 2
VIDEO_CONVERTER_TO_USE = "ffmpeg" # or use "avconv"
class RosVideoWriter():
def __init__(self, fps=30.0, rate=1.0, topic="", output_filename ="", output_path = "", 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 = {}
self.out_path = output_path
def parseArgs(self, args):
opts, opt_files = getopt.getopt(args,"hsvr:o:t:p:",["fps=","rate=","opath=","topic=","start=","end=","prefix="])
for opt, arg in opts:
if opt == '-h':
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", "--opath"):
self.out_path = 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
# 根据话题类型过滤话题
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 == "":
return True;
if(datatype=="theora_image_transport/Packet"):
if (self.opt_topic != "" and self.opt_topic == topic) or self.opt_topic == "":
return False;
if(datatype=="sensor_msgs/Image"):
if (self.opt_topic != "" and self.opt_topic == topic) or self.opt_topic == "":
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.out_path != "":
out_file = self.out_path + self.opt_prefix + str(topic).replace("/", "_")+".mp4"
else:
out_file = self.opt_prefix + str(topic).replace("/", "_")+".mp4"
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]
if self.out_path != "":
for f in os.listdir(self.out_path):
if f.find(bagfile[:-4])>=0 and f.find(".mp4")>=0:
os.remove(self.out_path + f)
else:
for f in os.listdir("./"):
if f.find(bagfile[:-4])>=0 and f.find(".mp4")>=0:
os.remove(self.out_path + f)
#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:
# np_arr = np.fromstring(msg.data, np.uint8)
# cv_image = bridge.compressed_imgmsg_to_cv2(msg, "bgr8")
self.write_output_video( msg, topic, t, MJPEG_VIDEO)
# 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)!')
sys.exit(1)
else :
videowriter = RosVideoWriter()
try:
opt_files = videowriter.parseArgs(sys.argv[1:])
except getopt.GetoptError:
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")
脚本使用方法
rosbag2video.py [--fps 25] [--rate 1] [-o outputfile] [-v] [-s] [-t topic] bagfile1 [bagfile2] ...
Converts image sequence(s) in ros bag file(s) to video file(s) with fixed frame rate using ffmpeg
ffmpeg needs to be installed!
--fps Sets FPS value that is passed to ffmpeg
Default is 25.
-h Displays this help.
--ofile (-o) sets output file name.
If no output file name (-o) is given the filename '.mp4' 代码是参照github上的一个开源项目进行修改的，可参照完整项目地址。