wireshark tool?

Does such a tool exist that I can apply a display filter against a file to pull only the data stream out I need into a new file?

I have a daily rolling buffer wireshark capture that runs. A ring buffer is used to break out into 150mbs chunks. I merge the files I need, then open up the merge file with wireshark to look at the data. This particular data stream created quite a large file, and wireshark is having issues with it. Individually each 150mbs file is ok, but the merge file is just too much to handle.