Are there any third party tools for fixing rosbag files?

edit

We just carried out an experiment in which 15 minutes of raw depth images were recorded, at an approximate rate of 1GB/min. The resulting bag file looked the correct size, but 'rosbag info' shows that no messages were recorded. For example:

asymingt@asymingt:~/Desktop/SSLA$ rosbag info JSC\ First\ Working\ Test\ Picoflex_2017-02-28-11-55-22.bag 
path:    JSC First Working Test Picoflex_2017-02-28-11-55-22.bag
version: 2.0
size:    14.6 GB
asymingt@asymingt:~/Desktop/SSLA$

In fact, no start or end date are shown either. Only the size and bag version are printed. I have tried the rosbag fix, check and reindex commands without luck. This is the first time we have seen this behaviour and, unluckily for us, it affects an experiment that cannot be easily repeated.

Are there any third party tools for fixing or extracting data from corrupted bag file?