Iain Richardson on his Blog vcodex.com asks the question “HEVC : is it really twice as good as H.264?” Iain states that the new standard for video compression, High Efficiency Video Coding or HEVC, is claimed to require “half the bandwidth for high quality video transmission”, compared with the older H.264/AVC standard. So Iain conducted his own sample test to see if the claim holds true and concluded, that at this stage HEVC “at half the bitrate of H.264, the HM10 codec does not deliver the same quality.”
If the same video clip is encoded with H.264 at a particular bitrate, and with HEVC at half the bitrate, then the quality of the decoded HEVC video should be at least as good as the decoded H.264 video.
Here’s an example. This is a close-up of a frame from the sequence “Kristen and Sara”, 720p resolution. On the left, the sequence has been encoded at 800kbps using the x264 video encoder, a popular H.264 implementation. On the right is the same frame from the sequence encoded at 420kbps using the HEVC Test Model encoder, HM10.0.
Left: x264 at 800kbps. Right: HM10 at 420kbps.
As Iain points out the two frames look very similar, with some detail lost in the HEVC version of the file.
x264 at 800kbps: extreme close-up
HM10 at 420kbps: extreme close-up
Please visit Iain Richarson’s Blog HERE to get his full test results working with HEVC video files.