H.264/AVC is so slow

BBC engineers have revealed their research into  H.265/HEVC video compression and claim that it is 50 per cent better than the older  H.264/AVC standard.

The BBC published the results and an extensive analysis of its formal verification tests of the H.265/HEVC video compression standard in the IEEE Transactions on Circuits and Systems for Video Technology (TCSVT) journal, which we buy for the centrefold.

Apparently the BBC R&D video coding research team focused on evaluations of UHD content and analytics as part of a standardisation process.

The High Efficiency Video Coding (HEVC) standard  was to provide significantly improved video compression compared with its predecessors; H.264/AVC being the most recent. This standard was ratified in 2013 as H.265 by the ITU-T and as MPEG-H Part 2 by ISO/IEC.

The subjective tests used human viewers to test the compression gains of the new video coding standard.  This had normally been done objective metrics (e.g. Peak Signal to Noise Ratio – PSNR). The PSNR based computations had shown up to about 50% bit rate savings in HEVC compared to the previous standard of H.264/AVC, for similar video quality.

The subjective tests used a carefully selected set of coded video sequences at four different picture sizes: UHD (3840x2160 and 4096x2048), 1080p (1920x1080), 720p (1280x720) and 480p (832x480), at frame rates of 30Hz, 50Hz, or 60Hz. Video content was chosen to represent diverse spatial and temporal characteristics, and then coded using HEVC and AVC standards at a wide span of bit rates producing a variety of quality levels.