Google VP8: "Bali" to offer faster encoding
The WebM project, led by Google, has released a new version of the VP8 Codec SDK for the free VP8 web video format. Code-named "Bali" (after the duck of the same name), the development kit of the libvpx 0.9.6 codec library aims to improve encoding performance while offering better video quality without making any changes to the VP8 specifications.
Compared with the first version (0.9.0) and the previous release (0.9.5 "Aylesbury"), Bali's "Best" encoding mode on x86 processors is said to be up to 450% faster than VP8 0.9.0, and around 35% faster than "Aylesbury". The encoder is also said to work moderately faster on ARM platforms with NEON extension: 7% on an ARM Cortex A9 (single core). The developers said that performance scales linearly with the number of cores; on Nvidia's Tegra 2, real-time encoding is reportedly 21% to 36% faster (and therefore less resource hungry) than with "Aylesbury".
According to the developers, mathematical metrics (PSNR, SSIM) prove that the image quality produced by the codec is 6% better than that of the previous version. The encoder now offers a "Constrained Quality" mode and is said to achieve a more consistent high video quality across entire video clips using two-pass encoding, as well as improved quality on "noisy" source videos through optimised temporal filtering. Various functions were rewritten in assembler, and the developers also improved the SDK's multi-threading (for ARM) and multi-core support.
"Bali" is available to download and can be cloned from the WebM project's Git repository. The next release, "Cayuga", is to follow in the second quarter of 2011 and will reportedly offer further performance improvements.
VP8 was originally created by On2 Technologies (formerly "The Duck Corporation"), who were taken over by Google in early 2010. Last May, Google released the codec under an open source licence and founded the WebM project to establish VP8 and its chosen container format, WebM – a lean version of the Matroska container (MKV) – as a competitor to the patent-encumbered MPEG-4 AVC (H.264) web video standard. WebM is made available under a "three clause" BSD licence, an OSI approved open source licence.