I have some video files which were stored with the format headers in separate files. Unfortunately, the disk crashed, and the header information has been lost. I still have large chunks of stream data though. Before I start writing brute-force code to figure out the parameters, are there any tools available for recovering this sort of thing?
There are no such tools to my knowledge. You will probably have to make these headers yourself. Usually you don't have all that much parameters to set in a format header. If all the streams have the same origin you will be able to use the same header for all streams.
Just look into the format specification and edit a sample header in a way it could fit your stream data.