The file you're looking for is called people.bin and it's inside data\cd\cr_us.lgp (and in other language variants).
It's split into 539 records, each 64 bytes, one per credits line (it also includes empty lines).
Each line starts with two 4-byte markers indicating the font style. First one specifies the style (big/small, with or without underline), second one is the color.
Text is encoded in a different way than what everything else in the game does, but it's very simple: letter "A" is 00, "B" is 01, and so on. Space is 2F. Separator (for two names in one line) is 30. Each line ends with 7F and text after the 7F is ignored until the next line starts (there's some garbage data in many lines after the 7F byte, just ignore it).
Finally the last 4 bytes of each record seems to be line height (so they could create multiline headers).
You should be able to figure out the rest from here.