https://www.videoconverterfactory.com/tips/h265vsh264.html
H.264 (Advanced Video Coding) and H.265 (High Efficiency Video Coding) are comparable video encoding standards.
H.265 is the newer of the two codecs and generally has a much higher compression ratio than H.264, though is not supported on as many devices as H.264.
Older
Better compatibility than H.265 for playback
Lower compression ratio than H.265
Newer
Higher quality at same bitrate
Higher compression ratio than H.264
Longer compression time due to more complex compression algorithm
For my project, I will encode the same video file into H.264 (AVC) and H.265 (HEVC) and compare the encoded files in terms of three factors:
Disk space
If there are any noticeable visual differences between the encoded video files
Performance when streaming over a local network to the same client.
I am interested in comparing these two codecs as on my home server as I have TBs of video, a majority of which is encoded in H.264. By performing this comparison, I will be able to use the findings to determine the value that I would get out of re-encoding my H.264 video to H.265, which could save potentially hundreds of GBs of disk space but would take a significant amount of time to perform.