Whenever I play a 1080p video on my computer, it seems to be playing blocky/pixelated but when I am playing a game, it looks proper 1080p with no blocks or pixels. Here are my pc specs:

Processor - Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz, 3401 Mhz, 4 Core(s)

Graphics Card - NVIDIA GeForce GTX 650 Ti 

Hard Drive - TOSHIBA 1TB DT01ACA100 ATA