This paper presents a hierarchical parallel MPEG-2 decoder for playing ultra-high-resolution videos on PC cluster based tiled display systems. To maximize parallelism while minimizing the communication requirements for a PC cluster, our algorithm uses a two-level splitter approach, where a root splitter splits an MPEG-2 video stream at the picture level and passes them to k second-level splitters, each of which splits the pictures into macroblocks and sends them to decoders according to their screen locations. Our experiments with various configurations show that this system is highly scalable and has a low and balanced communication requirement among the PC nodes. On a display wall system driven by 21 PCs, the implementation can play back a video at 38.9 frames per second.