- Next-gen codecs provide 50% bitrate improvements over x264, but are 10-20x as slow at the top settings required to accomplish such results.
- Normalized for CPU usage, libvpx already has some selling points when compared to x264; x265 is still too slow to be useful in most practical scenarios except in very high-end scenarios.
- ffvp9 is an incredibly awesome decoder that outperforms all other decoders.
https://blogs.gnome.org/rbultje/2015/09/28/vp9-encodingdecod...
The bitstream spec is definitely public.
It's only a draft, and two years out of date, but it is public.
Lack of a non NDA public spec may have made things more difficult for some but it certainly didn't stop everyone.
We didn't have this luxury with HEVC. The HEVC reference decoder (HM) is horribly complex, and has been easy to crash in many different ways for years. As a consequence, it could by no means be considered as authoritative. Which is a pity, because there were a lot of discrepancies between the reference decoder and the .doc spec.
Not to take away from the hard work which has gone into ffvp9 but that should be “all other open-source decoders” without benchmarks comparing it against the proprietary implementations which most people actually use. ffvp9 be great but still the wrong choice if someone has a hardware/GPU-accelerated H.265 codec in their OS and would prefer longer battery life to use of free software.
I have not had issues playing 1080 x265 content videos on any of my mobile devices past 18 months or so since they've started releasing them. There's just something to be said about 200-300MB per 1080p episode and about 700MB per movie. Can cram an entire library to most of my current mobile devices for a flight/long commute without having to worry about SD cards/USB OTG.
Yes H.265 encoding speed is 10-20x slower (at the highest quality setting) but the decoding speed was only 20% slower than H.264. And it is still quite faster than 60fps below which almost all movie content exists.
If all that mattered in a codec was encoding speed VP9 would be dominant. But it isn't. It's largely irrelevant compared to decoding speed (majority of codec users) and device support. The latter which H.265 is in an unassailable position.
And encoding speed really only matters as far as real time services go like streaming services.