Good News from Germany

Today a court in Mannheim, Germany, ruled that VP8 does not infringe a patent owned and asserted by Nokia. This decision is an important and positive step towards the WebM Project's ultimate goal: ensuring the web community has an open, high-quality, freely licensed video codec. Google's intervention in the underlying lawsuit (Nokia v. HTC) was a strong show of support for open standards like VP8.

We believe that the web succeeds through community-developed innovation. VP8 brings that principle to video: a codec that anyone can use and build upon. The WebM Project’s next-generation video codec, VP9, is already available and we look forward to continuing our work with the broader community to help video on the open web keep getting better, faster.

Matt Frost is Senior Business Product Manager for the WebM Project
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VP9 Lands in Chrome Dev Channel

VP9, the WebM Project's next-generation video codec, was recently enabled by default in Google Chrome Dev channel. A key goal of the WebM Project is to speed up the pace of video-compression innovation (i.e., to get better, faster), and the WebM team continues to work hard to achieve that goal. As always, WebM technology is 100% free, and open-sourced under a BSD-style license.

VP9 development began eighteen months ago. In the short time since, according to our internal tests, we've produced a codec that shows video quality that is slightly better than HEVC (H.265) and is 50% better than VP8 and the best implementations of H.264 high profile.

With the bitstream defined and VP9 deployed in Chrome, we'll begin work on refining the VP9 toolset for developers and content creators. VP9 is already available in the open-source libvpx reference encoder and decoder. We’ll now be working on optimizing libvpx for speed and performance, and working—with help from partners and the WebM community—to ensure that VP9 is positioned to integrate with the major encoding tools and consumer platforms, including mobile and embedded

Improved libvpx tools and documentation will roll out over the coming months. Monitor our progress on the VP9 summary page and our mailing lists.

Matt Frost is Senior Business Product Manager for the WebM Project
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VP9 Codec Nears Completion

Last week, we hosted over 100 guests at a summit meeting for VP9, the WebM Project’s next-generation open video codec. We were particularly happy to welcome our friends from YouTube, who spoke about their plans to support VP9 once support lands in Chrome.

As discussed at the summit, we’re putting the finishing touches on the VP9 bitstream and finalizing launch plans. We cut the beta bitstream on May 3, and are now accepting final contributor comments and making decisions about experimental code. A draft bitstream specification is well underway.

As always, anyone may study the latest VP9 code in the experimental branch* of the libvpx codebase using the instructions here, or browse recent commits to experimental.

We’ll freeze the VP9 bitstream on June 17, allowing Chrome and Chrome OS to enable VP9 by default. See our recent update on the webm-discuss mailing list for more about our plans as we approach the freeze, and follow the list to get further updates.

Matt Frost is Senior Business Product Manager for the WebM Project.
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* Please disregard the outdated vp9-preview branch.

Onward!

Giddy up!

Exciting things are happening with codec development here at the WebM Project. Of particular note is our recent announcement of an agreement with MPEG LA and eleven patent holders for a royalty-free license in support of VP8.

Now that the distractions of the MPEG LA licensing initiative are behind us, it's a good time to review recent improvements with VP8 and take stock of VP8 adoption and proliferation. In the coming weeks, we'll be posting a series of updates on this blog about important developments around the VP8 codec, as well as our plans for VP9.

But first, we’d like to clarify a few things about the MPEG LA agreement. While most observers quickly understood the nature of the agreement, a handful of bloggers have mischaracterized it. Let’s set the record straight.

We entered into the agreement for two reasons:

• to dispel the cloud cast by MPEG LA's announcement of efforts to form a pool around VP8;
• to build the strongest possible IP foundation under VP8 and VP9.

We realize that dramatic headlines attract readers, but despite some of the speculation, there was never any lawsuit, and there was certainly no "finding" or "admission" of infringement.

Understandably, we’ve had to keep quiet while the MPEG LA talks were in progress. Now that it’s settled, we will redouble our efforts to engage directly with the WebM community and open web platform developers around the world.

So stay tuned for more news!

John Luther is Product Manager of the WebM project.
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W3C CEO Jaffe on VP8 Licensing

It's great to read supportive statements like this one from Jeff Jaffe stemming from our recent announcement of an agreement with MPEG LA and eleven patent holders for a royalty-free license in support of the VP8 video codec.

VP8 and MPEG LA

Today Google Inc. and MPEG LA, LLC announced agreements that will result in MPEG LA ending its efforts to form a VP8 patent pool. The arrangement with MPEG LA and 11 patent owners grants a license to Google and allows Google to sublicense any techniques that may be essential to VP8 and are owned by the patent owners; we may sublicense those techniques to any VP8 user on a royalty-free basis. The techniques may be used in any VP8 product, whether developed by Google or a third party or based on Google's libvpx implementation or a third-party implementation of the VP8 data format specification. It further provides for sublicensing those VP8 techniques in one successor generation to the VP8 video codec. We anticipate having the terms of our sublicense ready in the next few weeks. When those terms are ready we will blog about them here, so watch this space. We launched the WebM Project in May 2010 with the goal of providing the web with a high-quality, open, royalty-free video codec that anyone can use, and that can inspire future innovators. Today's announcement is an important step toward that goal. Matt Frost is Senior Business Product Manager for the WebM Project.

Wikimedia Launches HTML5 Media Player with WebM Support

The Wikimedia Foundation — the awesome folks behind Wikipedia — has deployed an advanced HTML5 media player across its network of award-winning websites. The player accepts audio and video in the royalty-free formats associated with WebM and Ogg.

Developed in collaboration with Kaltura and built upon the Mediawiki platform's TimedMediaHandler extension, the player integrates with a server-side transcoding pipeline and provides a collaborative caption editor to facilitate translations.

Congratulations to Wikimedia for helping move open web video another big step forward.

Sixth Generation VP8 Hardware Accelerators Released

Today we’re launching the G1 decoder “Fairway” and the H1 encoder “Foxtail”, the sixth generation VP8 hardware IP cores.

By redesigning the DMA engine architecture in the Fairway decoder we’ve improved VP8 decoding speed by 50% in a typical network-on-chip environment that exposes IP cores to very long memory latencies. Fairway is also using 20% less SRAM than the previous releases making the chip manufacturing cheaper.
Our target with the encoder was to further stretch the limits of single-pass, low-latency VP8 coding. The diagram below compares Foxtail to older IP encoder releases, as well as to the libvpx software VP8 encoder, configured to WebRTC quality settings. The results show that running a WebRTC session in a device with Foxtail VP8 encoding produces better quality video than libvpx across a wide range of datarates. 
We achieved the quality improvements in Foxtail by implementing macroblock adaptive rate-distortion optimization. Compared to the initial “Anthill” IP core release launched in March 2011, we’ve improved the compression rate by up to 40%.
The new releases, targeted for ASIC developers, are available at no cost by requesting a license at webmproject.org/hardware. Integration support services and multi-standard versions are available from Verisilicon. The VP8 hardware cores have now been licensed to over 80 chip companies, and both the decoder and encoder are in mass production from a number of partners.
Looking forward, the hardware team will be focusing more attention on the next generation codec development including the VP8 experimental branch. 
Aki Kuusela is engineering manager for the WebM project hardware team.

VP8 Codec SDK "Eider" Released

"Eider," the fifth named release of the VP8 Codec SDK (libvpx), is now available. You can download the Eider libvpx snapshot (version 1.1.0) from our Downloads page, or clone it from our Git repository.

In addition to a number of enhancements, this release fixes a decoder bug first introduced in v1.0.0, "Duclair," so all users of that release are encouraged to upgrade.

Note that the VP8 format definition has not changed, only the SDK. Eider is ABI and API compatible with Duclair. Code changes shouldn't be required in most applications, but please consult the "Upgrading" instructions in the CHANGELOG. In particular, use of the encoder's spatial denoiser has changed.

Enhancements

• Eider adds a motion-compensated temporal denoiser, which gives higher quality than the older spatial denoiser. 
• We've added support for new compilers and platforms, including improved Xcode support, Android x86 NDK build, OS/2 support and SunCC support. 
• Input resolution may now be changed without re-initializing the codec. 
• The vpxenc application has initial support for producing multiple encodes from the same input in one call. 

Performance Improvements

With Eider, our focus was on decoder speed and realtime encoder speed.

• Large realtime encoding speed gains with little quality loss are possible using the on-the-fly bitpacking experiment. Video conferencing-style encodes can be up to 13% faster, depending on resource allocation, with loss in the range of 0.2dB.
• Decoder speed improved 2.5% vs. Duclair. 
• Two-pass encoding of slideshow-like material will see significant speed improvements. 

Quality is consistent with Duclair, but saw some useful tweaks:

• Reduced blockiness in easy sections, by penalizing intra modes. 
• Improved quality of static sections (like slideshows) with two-pass encoding. 
• Improved keyframe sizing with multiple temporal layers. 

Many thanks to all who worked on Eider, and welcome to four new contributors:

• KO Myung-Hun 
• Marco Paniconi 
• Priit Laes 
• Takanori MATSUURA 

John Koleszar is a software engineer at Google.

WebM Gaining Momentum in Hardware

Hardware product cycles are very long, especially from the software developer’s perspective. However, in just under two years after the launch of the WebM Project, the leading chip vendors are bringing to the market full hardware support for VP8 real time and streaming video decoding and encoding at 1080p resolution.

In addition to the K3V2 application processor from Huawei and the RK30xx application processor from Rockchip announced at the Mobile World Congress 2012, ST-Ericsson has also finished developing a new platform with full VP8 support. “Working with the WebM team, ST-Ericsson is proud to demonstrate the first prototype devices using the NovaThor L9540™, a complete LTE platform for smartphones and tablets equipped with a high-performance application processor,” said Itai Dadon, Smartphone Business Development at ST-Ericsson. “The NovaThor L9540 incorporates a dual-core CPU, a powerful graphics engine and optimized multimedia accelerators in a high-performance, low-power solution which is fully geared for 1080p 30fps video playback of WebM on HTML5”.

And this is just the beginning. Many more of the world’s top semiconductor companies are also shipping 1080p VP8 capable mobile chipsets later this year.

In addition, Smart TVs with full HD WebM support are coming to the market from LG Electronics this spring, with other OEMs following soon after that. These will demonstrate in their big screens the HD quality of WebM videos by sites such as YouTube, which has been broadly supporting WebM in its html5 player since the launch of WebM in May 2010.

The overall goals of the WebM Project are broader than just getting hardware support for VP8. We’ve worked hard to make the usability of VP8 hardware accelerators in devices as straightforward as possible by leveraging widely adopted industry standard interfaces. Software developers can now easily take advantage of this extra horsepower, as we’ve achieved our goal of getting VP8 included in the recently released OpenMAX IL 1.2 specification. OpenMAX IL is used to access the video accelerators in some of the most popular operating systems today.

WebM hardware acceleration is now quickly emerging on chipsets and we expect to achieve rapid adoption of WebM acceleration on new devices in the coming year.

Aki Kuusela is Engineering Manager for the WebM Hardware Team.

VP8 Hardware Decoder Version 5 “Eagle” Released

Today we have made available the fifth generation of the silicon-proven G-Series 1 VP8 hardware decoder IP, internally called “Eagle”.

Eagle has the following key figures:

• 1080p 60fps VP8 decoding at 200MHz
• Maximum clock frequency 290 MHz, up by 32% (65 nm LP process, topographical synthesis)
• 357 kgates logic, 52 kB single-port SRAM
• Less than 2 MHz host CPU load

The increased performance levels allow a great multi-channel playback experience suitable e.g. for TV channel preview, multi-party video conferencing and multi-tab YouTube watching. The G-Series 1 decoder has recently secured multiple design wins in leading Smart TV and Set-Top Box SoCs, proving the performance to be at an appropriate level even for the highest-quality content decoding.

The G1 v5 VP8 decoder is available for licensing at no cost to chip manufacturers at the WebM Project’s hardware page. The multi-format version of the IP and support services for the VP8 standalone core are provided by our channel partner Verisilicon.

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 decoder release, we are targeting significant performance boost and smaller silicon footprint.


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

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.

VP8 Codec SDK "Duclair" Released

"Duclair," the fourth named release of the VP8 Codec SDK (libvpx), is now available. You can download the Duclair libvpx snapshot (version 1.0.0) from our Downloads page or clone it from our Git repository.

This release fixes a decoder crash bug introduced in Cayuga (v0.9.7), so we encourage all Cayuga users to upgrade.

Note that the VP8 format definition has not changed, only the SDK. Duclair is ABI incompatible with prior releases of libvpx, so the major version number has been increased to 1, and you must recompile your applications against the v1.0.0 libvpx headers. The API remains compatible, so code changes shouldn't be required in most applications.

New Features

This release introduces substantial new VP8 encoder features that are especially useful for real-time use cases such as live streaming and videoconferencing.

• Temporal scalability produces a video stream that can be decimated to different frame rates, with independent rate targeting for each substream.
• Multiframe postprocessing can make visual quality more consistent in the presence of frames that are of substantially different quality than the surrounding frames, as in the temporal scalability case and in some forced keyframe scenarios.
• Multiple-resolution encoding enables simultaneous encoding of the same content at different resolutions, resulting in much faster encoding than processing them separately.

Performance Improvements

In this release we focused on optimizing VP8 decoder speed and the real-time modes of the encoder.

• Decoder speed on x86 processors improved 10.5%. 
• Encoder improvements followed a curve where speed settings 1-3 improved 4.0%-1.5%, speeds 4-8 improved <1%, and speeds 9-16 improved 1.5% to 10.5%, respectively.

See the CHANGELOG for a complete description.

Thanks to everyone who worked on Duclair, and welcome to our four new contributors:

• Alpha Lam
• Deb Mukherjee
• Jeff Faust
• Rafaël Carré 

John Luther is Product Manager of the WebM Project.

Picking the Right Driver

We are very excited to announce the availability of the fourth generation G-Series 1 VP8 hardware decoder, internally codenamed “Driver”.

In this release, our focus has been on optimizing the VP8 bitstream decoder. The new architecture helps the IP run at 13% higher operating frequency allowing the decoder chips to reach higher frame rates or do multi-channel decoding more easily. At the same time, the new implementation has reduced the decoder’s logic gate count by 6% which directly cuts the production cost of each chip incorporating a WebM hardware decoder. Furthermore, the revamped design allows us to do even more optimizations for the next release. With future video requirements in mind, we designed Driver to decode up to 4k by 4k video resolutions.

To make the IP evaluation easier for a chip company, the deliverables now include a bit-exact decoder C-model. This allows partners to create their own test cases for thorough performance analysis.

Modern multi-core CPUs are getting powerful enough to decode HD video, so why is having hardware accelerators still useful? One good reason is battery life. We got our hands on one of the first commercial Android tablets based on the Rockchip RK2918 chip which uses our very own WebM hardware decoder and ran some tests. We charged the battery and looped a 480p video until the battery died. For the purpose of the experiment, we had to limit the resolution because the single-core CPU of the device could not run 720p @ 30fps in pure software. The battery test was done with the VP8 hardware acceleration enabled and disabled, and at two display brightness settings. The result: with the hardware offload the battery lasted up to 36% longer which gets us one extra movie to watch on that long flight! You can see the battery discharge vs. elapsed time plots below. Needless to say, using two or four CPU cores for HD video decoding in software uses even more power and widens the gap to hardware's benefit.

The G1 v4 VP8 decoder is now available for licensing at no cost at the WebM Project hardware page. The multiformat version of the IP and support services can be accessed through our partner Verisilicon.

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

Video Codecs 101

If you work in video compression, this has happened to you:

Someone asks what kind of work you do.  Maybe it's your aunt, or your dentist, or that nice girl you've started dating.  Now you're trapped.  Your only choices are (1) a long string of jargon that nobody wants to hear and makes folks sorry they asked, or (2) "I work with computers."

The problem is simple: most people don't know what video compression is, and you can't talk about it until they do.

What if you had a simple, three-minute animated video that explains the whole thing?  What if you could show it from your phone — right now, right there in the dentist's chair?  Now you can: Video Codecs 101.

Video Codecs 101

One video didn't seem like enough, so we made a second one that picks up where Video Codecs 101 leaves off.  After all, now that your dentist and your 10-year old niece are so smart about codecs, they'll want to know more.  So, how about another two minutes or so about what the WebM Project is doing to make video on the web faster, simpler and easier?

WebM: A Video Codec for the Web

We hope you find these videos fun and useful — and that they make your life a little easier, now that your friends finally know what you do. Enjoy.

You can learn more about WebM and even contribute to its success at webmproject.org.

Lou Quillio is Webmaster for the WebM Project.

Time of Dragonflies

Today, we are releasing the fourth generation of the Hantro H-Series 1 VP8 Hardware Encoder, developed under working title Dragonfly.

With the H1 v4 release we are offering the world’s best real-time VP8 video encoding of up to 1080p in mobile. It delivers an average PSNR improvement of 0.27 dB over the previous generation and produces higher quality video than any of our previous RTL designs.

The fourth version’s major improvements reducing the bitrate required for great video quality include:
- the usage of bicubic filter in motion estimation and reconstruction phases
- additional candidates in macroblock mode selection
- improved rate-distortion optimization in macroblock mode selection

The following figure compares the Dragonfly SSIM performance with the previous VP8 releases. One of our previous products, the 8290 H.264 hardware encoder, is also shown as a reference.

H1 Encoder SSIM comparison, Foreman CIF sequence at 200 kbps.

The visual comparison below shows how the level of preserved details increases with each new encoder release.

Foreman CIF sequence at 200 kbps.

Top-left: H1 v1, top-right: H1 v2, bottom-left: H1 v3, bottom-right: H1 v4.

H1 encoder helps users enjoy more hours1 of high-definition WebM video applications, such as those utilizing the open source WebRTC framework that allows free browser to browser video chat capability. For example, in battery operated devices like tablets, smartphones or netbooks, 1080p 30fps encoding with H1 requires less than 3 MHz of CPU cycles and 76 mW of power, while such a feat using the quad-core ARM Cortex A9 would take 2.3 GHz per core draining your battery at a rate of 3700 milliwatts 2.

H-Series 1 VP8 encoder as well as the silicon-proven G-Series 1 VP8 decoder, are available at no cost to chip manufacturers from the WebM Project’s hardware page. Our reseller partner Verisilicon also licenses the VP8 encoder as a part of the multi-format (VP8/H.264/MVC/JPEG) Hantro H1 encoder and offers support and maintenance service for the free VP8 cores.

In total, over 50 semiconductor companies have licensed the VP8 technology today. The first devices with 1080p VP8 decoding are today in the consumer market from nearly a dozen different brands (see example here), and the first chips capable of VP8 encoding will ship in 2012.

In our next release, we are focusing on speed improvements and silicon cost reduction, as well as adding new pre-processing and error resilience functionality to the encoder. We intend to implement new software and hardware algorithms to allow both objective and visual quality optimizations. The next release is planned for early Q1 next year.

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


1 Using a typical smartphone battery of 1500 mAh at the operating voltage of 3.5V, the H1 v4 encoder can theoretically encode 1080p video for 69 hours without charging the device.
2 Power consumption of the H1 encoder logic measured with the TSMC65nm LP process. SRAM or external RAM not included. ARM Cortex A9 CPU load measured using the libvpx Cayuga release on a quad-core ARM CA9 development board. Power consumption figure based on a 0.4 mW / MHz / core estimate.

VP8 Error Concealment in WebRTC

The WebRTC project has posted a demo of their implementation of VP8 error concealment in libvpx. The visual improvement is pretty striking. Check it out at the WebRTC blog.

WebM at the Open Video Conference

Members of the WebM team will be at the Open Video Conference (OVC) September 10th-12th in New York City. There are a number of sessions related to WebM and VP8 on the agenda (as well as an Open Media Developer's Working Group). If you're not registered to attend OVC already, what are you waiting for?

Third Generation VP8 Hardware Encoder IP “Cloudberry” Released

Starting today, “Cloudberry”, the third release of the Hantro H1 VP8 hardware encoder, is available at no cost through the WebM Project hardware page. Partners having already signed the online licensing agreement will receive an automatic update.

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.

VP8 Codec SDK "Cayuga" Released

Today we're making available "Cayuga," the third named release of the VP8 Codec SDK (libvpx). Note that the VP8 format definition has not changed, only the SDK. You can download the Cayuga libvpx snapshot (version 0.9.7) from the WebM Project Downloads page or clone it from our Git repository.

As promised, for Cayuga we targeted more areas for encoder speed improvements. Using our previous release ("Bali") as a benchmark, we’ve seen the following VP8 encoder improvements on x86 processors.

• +11.5% "Best" mode (at speed 0)
• +21.5% "Good" mode (at speed 0) 
• +22.5% "Real-time" mode (at speed 6, a typical speed for videoconferencing applications)

We also compared the encoder performance of "Cayuga" to our first named release ("Aylesbury") release and got the following results:

• +35% "Best" mode (at speed 0)
• +75% "Good" mode (at speed 0) 
• +52% "Real-time" mode (at speed 6)

These improvements are summarized in the following chart:

We saw the following improvements on ARM processors:

• On ARM Cortex A9 with Neon extensions, real-time encoding of video telephony content is 35% faster than Bali on single core and 48% faster on multi-core.
• On the NVIDIA Tegra2 platform, real time encoding is 40% faster than Bali.

For more technical readers, here are some detailed improvements we made in the libvpx Cayuga encoder:

• Improved the datarate control in one-pass realtime compression. 
• Improved one-pass variable bitrate (VBR) visual quality by average ~7% across a large collection of videos.
• Improved video conferencing user experience through error concealment, a feature that produces high visual quality frames even under conditions of substantial packet loss. 
• Improved the ARM v6 and v7 encoders and decoders through greater use of SIMD features and strong use of cache prefetching.

Thanks to everyone who worked on Cayuga, and welcome to our eleven new contributors:

• Alok Ahuja
• Alexis Ballier 
• Ronald Bultje
• Rafael Ávila de Espíndola
• Ralph Giles
• Stefan Holmer
• Mike Hommey
• Taekhyun Kim
• Aron Rosenberg
• Joshua Bleecher Snyder
• Thijs Vermeir

John Luther is Product Manager of the WebM Project.