Where are source files on libffplayer.so

I’ve found there are many libraries(.so) in aosp/device/rockchip/common/vpu/lib.

I want to see how rkffplayer works.

If not exist, can I get the source files on libffplayer.so?

is it librkffplayer.so ?
there is device/rockchip/common/vpu/lib/librkffplayer.so