A bit-stream buffer controller for a video decoder includes a first FIFO, a second FIFO, and an interrupt controller. The first FIFO is configured to store an input bit-stream. The second FIFO is configured to store a payload extracted from the input bit-stream. The interrupt controller is configured to generate an interrupt signal according to a fullness status of the first FIFO and the second FIFO such that the video decoder may be switched to load the payload without checking the fullness status each time the payload is loaded.