Third Generation VP8 Hardware Encoder IP “Cloudberry” Released
Moving along with our mission statement - creating the world’s best real-time video encoder - we’re again one step closer to our goal thanks to Cloudberry’s substantial quality gains. In PSNR comparisons, Cloudberry performs on average 1.27 dB better than our initial Anthill release, which we launched less than five months ago. It also beats the previous Blueberry release by 0.45 dB, with comparable increases using the SSIM quality metric.
We’ve also bridged an important milestone: Cloudberry is able to encode high-quality 720p video (video teleconference use cases) at well under 1 Mbps, as shown in the following chart.
The optimized Cloudberry control software is backwards compatible and will also benefit chips with the Blueberry hardware inside them, providing 0.08 dB average PSNR increase without any hardware changes required.
In our next release, we are focusing on further software-based quality improvements especially related to multipass encoding and optimal usage of VP8 Golden frames - both of which will benefit SoCs that use either Blueberry or Cloudberry. On the hardware side, we also have numerous improvements in mind, such as further optimizing the macroblock mode selection. This fourth release is planned to be available at the end of Q3.
The VP8 H1 encoder IP has been licensed already to nearly 40 semiconductor companies through the WebM Project, and more requests are pouring in. For licensing details about the H1, see our hardware page. Our reseller partner Verisilicon also licenses Cloudberry as a part of the multiformat Hantro H1 encoder.
For more technical readers, here is the list of new features in Cloudberry:
- RD-optimized quantization
- Improved intra/inter macroblock mode selection
- Improved inter macroblock RD functions
- Improved intra macroblock mode selection
- More macroblock level coding information returned to software (enables effective multipass optimizations)
The following curves show PSNR quality metrics for a 720p video call, comparing the H1 Cloudberry release to previous H1 releases and to the libvpx Bali software SDK release. As a point of interest, the Cloudberry encoder performs similarly to libvpx’s “-rt -cpu-used=-5” setting, which is equivalent to what a WebRTC based application can achieve on the fastest PCs.
Aki Kuusela is Engineering Manager of the WebM Project hardware team in Oulu, Finland.