sdram and pixel buffer

hi

i'm designing a JPEG decoder using DE2 board and i'm planning to make the sdram as the buffer, but then i realized that there is a pixel buffer core.

i have attached the picture showing the connection between the sdram and the pixel buffer. what i want to know is wether the sdram act as the buffer which is controlled with the pixel buffer, or it works in other ways.

and does the "default buffer start address" in the configuration of the pixel buffer refer to the base address of the sdram controller??

thank you very much for any help you can give