A new study has indicated that High Efficiency Video Coding has significant improvements over H.264 in ultra high-definition video.
The Sintel open source film was used in the study.
(Credit: Blender Foundation/www.sintel.org)
The study was performed by the Ecole Polytechnique Federale de Lausanne in Lausanne, Switzerland, and centred on the subjective quality of the video compression, rather than any of the more technical measurements.
The test involved showing three short (5 second) clips to subjects: a video of people on a street, a clip of traffic and an animated sequence from the film Sintel. These clips were played at resolutions at or above 3840x1744, with the maximum resolution shown being 3840x2160 or QFHD. Each clip had been compressed with both the AVC (H.264) and HEVC codec at five different bitrates, making 10 different versions of each clip. The viewers were then asked to make subjective ratings on how they perceived the quality of the clips.
In a statistically significant portion of the tests, the subjects preferred the HEVC codecs across all bitrates. Only at the highest bitrates did subjects find the quality of the AVC to be comparable to HEVC.
What this means is that HEVC can deliver quality video at ultra high definition resolution, at a significantly lower bitrate than the current prevailing codec. This is potentially most useful in the world of video-streaming, which suggests that these services will be able to offer UHD video, without becoming a "bandwidth killer" — good news for those still in pre-NBN Australia.
HEVC is on its way to be standardised and will probably be demonstrated at the IBC show in Amsterdam, Netherlands, in early September. This report is good news for proponents of HEVC, with the study concluding that the "video compression standard seems to be one of the key elements towards a wide deployment of 4K and 8K resolutions".