Because of their high capacity, videos are preferred for data hiding. Many approaches have been introduced to hide data into videos. Nowadays, HEVC which is newest video coding standard, has become potential target for data hiding. In this paper, data hiding is carried out into quantized transform coefficient of intra coded frames in HEVC. Matrix encoding is used in order to hide secret data to the frames of video. The main advantage of matrix encoding is that, it changes only one coefficient to hide more than one bits. Experimental results reveal that video contents coded with secret message, have negligible performance loss in terms of hit -rate while maintaining visual quality.