Replying to Sd card recovery

yowat?

so i have this sd-card with footage on it. its 16GB, and prolly 3/4 filled. i can watch the 20+ clips on the cam (pov vio), so they have to be intact.

but whenever i put the card into a computer, or connect to the cam with a cable, there is only 1 file of unknown size, and it has weird symbols in it (like chinese symbols, inverted and superscript "L"s). i cant open it with anything. the problem occurs accross different computers.

so i tried to recover the data with various programs. but i cant really get it going.

so far, i made an image of the sd card with "usbit", because i read thats smart so you can fuck around with it, without effectively altering the original data. then i mounted that image into daemon tools and tried to use "testdisk" to recover the data. but so far with no success, and i am not even sure if testdisk is the right choice.

so my question is, has anyone ever recovered data in a similar situation, and if so, which programs did you use? obviously googling is the bomb, but i dont know enough about data storage/indices and so on to know if i actually use the correct tools. (like the data isnt destroyed/lost when talking about the camera operating system)