Thursday, February 23, 2012

Fifth Generation VP8 Hardware Encoder Released

The fifth generation of the widely adopted H1 hardware encoder for VP8, internally known as “Evergreen”, has become available for licensing today. In the Evergreen release, we focused on improving the real-time communication features and on optimizing the encoding speed and visual quality. In particular, we have now enabled temporal and spatial scalability for VP8 video coding, a valuable feature for live streaming, multi-way video conferencing and security applications. To our knowledge, there are no companies offering H.264/SVC (scalable video coding) hardware encoders for chipset manufacturers at the moment. With this release, VP8 now offers scalable coding at the hardware level.

The Evergreen release includes the following new features:

  • Up to four layers of temporal scalability (e.g. 60, 30, 15, 7.5 fps)
  • Integrated image downscaler for spatial scalability in VP8 simulcasting
  • Support for up to four DCT partitions for faster multicore CPU decoding
  • Adaptive golden frame period and quantization
  • Improved chrominance intra prediction
  • Improved mode selection with multiple QP segments
  • Rate-distortion optimization for both PSNR and SSIM
  • Real-time frame PSNR feedback
These new features enable us reach the following performance improvements:

  • 30% faster encoding, requiring only 220 MHz clock rate for 1080p at 30fps
  • 40% improved external memory latency tolerance, making the IP suitable for Network-on-Chip architectures
  • On average 6% smaller bitrate at similar SSIM, or up to 0.7 dB higher PSNR over the previous H1 v4 “Dragonfly” encoder
Furthermore, by just updating the firmware, all v4 “Dragonfly” chipsets also get a nice boost of 4% smaller bitrate at similar SSIM quality.

More technical details are available at the WebM Project’s hardware page.

As shown in the rate-distortion curve for “ice” CIF sequence below, the hardware’s quality is comparable to the real-time mode (-rt -cpu-used=-5) of the recently launched libvpx “Duclair” encoder.

H-Series 1 VP8 encoder and the silicon-proven G-Series 1 VP8 decoder are available at no cost to chip manufacturers at the WebM Project’s hardware page. Our reseller partner Verisilicon licenses both IP cores as multi-format versions, and offers support and maintenance service for the free VP8 cores.

WebM Project releases a new generation video IP every quarter to allow the semiconductor licensees to always take advantage of the latest technology. In our next release, we have our eyes on making significant improvements to the subjective video quality at low to midrange bitrates.

Aki Kuusela is Engineering Manager of the WebM Project hardware team.