Is anybody familiar with the general structure of a Gamecube savefile?

I have a savefile from the Gamecube game, "Legend of Zelda: Ocarina of Time / Master Quest" and would like to extract the portion of the savefile that contains the native N64 save of Ocarina of Time.

I opened the gci file with a hex editor but I can't make heads or tails of any of it.

Thanks.

I got this to work.

Guided by what someone else had done for the other GCN Zelda OOT port (Collector's Edition), I identified a Gamecube specific header that was repeated twice in the file so I deleted it.
I then found out that the save data was byte-swapped compared to the Mupen64 PC .sra save file so I swapped the latter and that helped me identify a few key values that mark the beginning of the actual save data.
After this, it was just a matter making sure my file size and starting charcters on the converted Gamecube file were the same as the Mupen savefile.
I then byte-swapped the file and tried it on Mupen 64 PC and was pleasantly surprise to see my name on the savefile selection screen.

However, I was thrown a last curve at the end because when I frist tried the savefile on Wii64, it did not work. So, I byte-swapped the file again to return it to its original state and that did work. Strangely, Wii64's .sra files are byte-swapped compared to Mupen64's.

Anyway, mission accomplished.
If anyone ever need details about this, just PM me.

Regards.