When I received that data files from our first capture run I knew nothing about them except that they had a file extension of ``.c3d''. I found a large web site devoted to the format, and specification in hand I set out to write my own parser. Eventually I discovered that this was much more complex than expected, and decided I would be better off using someone else's parser.
The Matlab parser was chosen primarily based on the fact that it was the only one that did not crash or hang. I wrote a wrapper on top of this code that exported the Matlab arrays to a text file. There were continual problems with this data, and after a close look at the Matlab parser I discovered that it was hard coded to use only certain channels of the file. There was no way of knowing what channels were actually being use so the Matlab parser had to be scrapped.
My next choice was a simple Windows program [C3DEXPORT]that read in the files and exported to a text file. This one was not used earlier because it frequently hung or crashed, but with some care it was able to reliably export my data.