ARM has been in the process of updating its premium mobile suite of IP in the last month or so. Destined to arrive in high-end smartphones at the beginning of next year, ARM hopes silicon partners will make use of the energy-efficient Cortex-A73 CPU, brand-new Mali-G71 graphics and display and video processors, which are currently headlined by the Mali-DP650 and Mali-V550, respectively.
The second-generation Mali-V550, launched in October 2014, uses a scalable architecture to offer varying levels of encode and decode performance. A single core can encode/decode content at a resolution and framerate of 1080p60 while an eight-core configuration is able to increase this all the way up to 4K120. Keeping up with the times, Mali-V550 offers support for the HEVC (H.265) codec on both fronts.
ARM and other IP designers accelerate codecs in hardware once they become pervasive enough, and the prominence of codec is largely defined by who backs them. Google's VP9 is used at up to 4K resolutions on YouTube and has been supported on the Android operating system since 4.4 (KitKat), meaning that video processor hardware updates have been happening over the last year or so, though Mali-V550 does without.
All images courtesy of ARM
So it's no surprise to note that ARM is launching new video-processing hardware under the codename of Egil. This new block improves upon its predecessor by having baked-in support for VP9 Profile 0 - 8-bits per sample and 4:2:0 chroma subsampling - for both decode and encode. Adding further quality, Egil supports Profile 2, meaning 10 bits per sample.
Most leading mobile processors feature VP9 decoding but, right now, only Intel's Skylake offers VP9 full encode. Egil, therefore, will be specification-comparable to the best chips when available in six months time or so.
Scalability is once again an important part of Egil's armoury. The increased performance enables Egil to offer full 4K120 support with two fewer cores - six vs. eight - compared to Mali-V550. Both video processors share the ability to simultaneously encode and decode and can also use multiple codecs concurrently.
Mali-V550 uses a technology called Motion Search Estimation (MSE), which reduces power and bandwidth requirements by analysing frames and noting the difference between them. Should there be none in a certain part of the scene, MSE skips over these and saves power. ARM says it has further improved MSE for Egil through an engine redesign, though no additional power-saving numbers were provided.
ARM Egil, which will likely be productised as Mali-V650, is a logical step in improving the overall SoC performance for leading smartphones. Now compatible with Google's VP9 codec and improved through incremental updates, expect to see it in silicon soon.
