fix_bag_tf.py

#!/usr/bin/env python

from __future__ import print_function

import sys
import os

from multiprocessing import Pool

import rosbag

from tf.msg import tfMessage


def fix_bag_tf(args):
    (lambda bag_name, fixed_bag_name:

     ((lambda bag, fixed_bag:

       [(fixed_bag.write(topic, tfMessage(msg.transforms), stamp)
         if topic.find('/tf') >= 0
         else (fixed_bag.write(topic, msg, stamp)))
        for topic, msg, stamp in bag.read_messages()]

      )(rosbag.Bag(bag_name, mode='r'),
        rosbag.Bag(fixed_bag_name, mode='w', compression='bz2'))

      if not os.path.exists(fixed_bag_name) else None)
     or print('Converted {}'.format(bag_name))

    )(*args)

((print('usage: {} THREADS BAG [BAG ...]'.format(sys.argv[0])) and sys.exit(1))
 if len(sys.argv) < 3
 else
 Pool(int(sys.argv[1])).map(
   fix_bag_tf,
   [(bag_name, '{}_fixed{}'.format(*os.path.splitext(bag_name)))
    for bag_name in sys.argv[2:]
    if not bag_name.endswith('_fixed.bag')]))