This thesis evaluates the performance of two video codecs, x264 and x265, in terms of bitrates and subjective quality. The methodology involves video encoding, simulated transmission, bitrate calculation, and subjective quality assessment. In the video encoding step, three YUV videos are encoded using the specified Quantization Parameters (QPs) for x264 and x265. The purpose is to compare the performance of the two codecs in terms of bitrates and Peak Signal-to-Noise Ratio (PSNR). Simulated transmission is conducted to collect data on bitrates, PSNRs, and quality levels for each scenario. The encoded videos are subjected to different methods defining specific quality levels for different segments. The number of bits received at the user side and the quality levels used are recorded to evaluate the codecs' performance under various scenarios. Bitrate calculation determines the total number of bits each method receives on the user side. This analysis provides insights into the required bitrate for delivering video content at different quality levels. The subjective quality assessment uses the DSCQS (Double Stimulus Continuous Quality Scale) approach. Compiled videos for each scenario and codec are presented to human subjects who rate the quality based on their personal opinions. Average opinion scores are calculated to compare the quality between x264 and x265 for each scenario.By conducting this evaluation, the thesis aims to provide a comprehensive understanding of the performance of x264 and x265 codecs in terms of bitrates and subjective quality. The findings will contribute to the field of video coding and assist in making informed decisions regarding codec selection for various applications.