Archive for December, 2014

H.265: An Alternative History

Saturday, December 6th, 2014

As you might remember, alternative history genre is modelling events based on real history but with something gone differently. Here’s what could’ve happened with H.265 but didn’t.

So, finally there’s a new standard released — ITU H.265. It promises twice as low bitrate for the same picture quality in H.264. Yet people do not care much about it since industry leaders offer their solutions:

China introduces their new standard for video coding — Hybrid Enhanced Video Standard or HEVS for short. It features quadtree representation of coding blocks, more than thirty spatial prediction modes, block transforms from 4×4 to 32×32 and has one unique feature — motion vectors that implicitly take mirror references from reference picture lists. This standard is nominated for main video coding standard on CUVRD (China ultraviolet ray disc) but gains little popularity outside China.

On2 makes a new codec named VP9 that has no open specifications. After tedious reverse engineering it turns out to employ coding scheme from VP5 times, spatial and motion prediction from H.265 with slightly altered coefficients and overall coding scheme from H.265 drafts.

Re… buffering… alNetworks releases NGV at last (fourcc RV50). Again, after long studies of binary specification, it turns out to be based on H.265 drafts with some in-house improvements: using context-specific codebooks for elements coding, ⅕-pel motion compensation (which is implemented as motion vectors pretended to be ⅛-pel but in reality several different positions are handled by the same function). The codec goes very popular in China for some reason.

Sorenson releases SVQ7. It is based on old H.265 draft and employs â…™- and â…›-pel motion compensation. It has some additional features like watermarking and quickly becomes the codec of choice for QuickTime.

P.S. Good thing nothing like this has really happened.