VP8

VP8 is a video compression format owned by Google and created by On2 Technologies as a successor to VP7.

In May 2010, after the purchase of On2 Technologies, Google provided an irrevocable patent promise on its patents for implementing the VP8 format, and released a specification of the format under the Creative Commons Attribution 3.0 license. That same year, Google also released libvpx, the reference implementation of VP8, under a BSD license.

VP8 is currently supported by Opera, Firefox, Chrome, and Chromium.

    History

    VP8 was first released by On2 Technologies on September 13, 2008, as On2 TrueMotion VP8, replacing its predecessor, VP7.

    After Google acquired On2 in February 2010, calls for Google to release the VP8 source code were made. Most notably, the Free Software Foundation issued an open letter on March 12, 2010, asking Google to gradually replace the usage of Adobe Flash Player and H.264 on YouTube with a mixture of HTML5 and a freed VP8.

    On May 19, 2010, at its Google I/O conference, Google released the VP8 codec software under a BSD-like license and the VP8 bitstream format specification under an irrevocable free patent license. This made VP8 the second product from On2 Technologies to be opened, following their donation of the VP3 codec in 2002 to the Xiph.Org Foundation, from which they derived the Theora codec. In June 2010, Google amended the VP8 codec software license to the 3-clause BSD license after some contention over whether the original license was actually open source.

    In February 2011, MPEG LA invited patent holders to identify patents that may be essential to VP8 in order to form a joint VP8 patent pool. As a result, in March the United States Department of Justice (DoJ) started an investigation into MPEG LA for its role in possibly attempting to stifle competition. In July 2011, MPEG LA announced that 12 patent holders had responded to its call to form a VP8 patent pool, without revealing the patents in question, and despite On2 having gone to great lengths to avoid such patents.

    In November 2011, the Internet Engineering Task Force published the informational RFC 6386, VP8 Data Format and Decoding Guide.

    In March 2013, MPEG LA announced that it had dropped its effort to form a VP8 patent pool after reaching an agreement with Google to license the patents that it alleges "may be essential" for VP8 implementation, and granted Google the right to sub-license these patents to any third-party user of VP8 or VP9. This deal has cleared the way for possible MPEG standardisation as its royalty-free internet video codec, after Google submitted VP8 to the MPEG committee in January 2013.

    In March 2013, Nokia asserted a patent claim against HTC and Google for the use of VP8 in Android in a German court; however, on August 5, 2013 the webm project announced that the German court has ruled that VP8 does not infringe Nokia's patent.

    Implementations

    Encoding

    Currently, libvpx is the only[] software library capable of encoding VP8 video streams. An encoder based on the x264 framework called xvp8 is under development by the x264 team. The WebM Project hardware team in Finland released an RTL hardware encoder for VP8 that is available at no cost for semiconductor manufacturers.

    In a comparison done in May 2011, the libvpx encoder was found to be slow compared to common H.264 encoders and used up to 213% more data for the same quality video, when used in videoconferencing applications.

    A Video for Windows wrapper of the VP8 codec based on the Google VP8 library (FourCC: VP80) is available.

    The Nvidia Tegra 4 mobile chipset has full VP8 hardware encoding and decoding.

    Nexus 5 could use hardware encoding

    Decoding

    libvpx is capable of decoding VP8 video streams. On July 23, 2010, Fiona Glaser, Ronald Bultje, and David Conrad of the FFmpeg Team announced the ffvp8 decoder. Through testing they determined that ffvp8 was faster than Google's own libvpx decoder. The WebM Project hardware team released an RTL hardware decoder for VP8, that is releasable to semiconductor companies at zero cost. TATVIK Technologies announced a VP8 decoder that is optimized for the ARM Cortex-A8 processor.Marvell's ARMADA 1500-mini chipset has VP8 SD and HD hardware decoding support (used in Chromecast).Intel has full VP8 decoding support built into their Bay Trail chipsets.Intel Broadwell also adds VP8 hardware decoding support.

    Related formats

    WebM

    Also on May 19, 2010, the WebM Project was launched, featuring contributions from "Mozilla, Opera, Google and more than forty other publishers, software and hardware vendors" in a major effort to use VP8 as the video format for HTML5. In the WebM container format, the VP8 video is used with Vorbis audio. Internet Explorer 9 will support VP8 video playback if the proper codec is installed.Android is WebM-enabled from version 2.3 - Gingerbread. Since Android 4.0, VP8 could be read inside mkv and WebM could be streamed.Adobe also announced that the Flash Player will support VP8 playback in a future release.

    WebP

    On September 30, 2010 Google announced WebP, their new image format, on the Chromium blog. WebP is based on VP8's intra-frame coding and uses a container based on Resource Interchange File Format (RIFF).

    Comparison with H.264

    While H.264/MPEG-4 AVC contains patented technology and requires licenses from patent holders and limited royalties for hardware, Google has irrevocably released all of the VP8 patents it owns under a royalty-free public license.

    According to a comparison of VP8 (encoded with the initial release of libvpx) and H.264 conducted by StreamingMedia, it was concluded that "H.264 may have a slight quality advantage, but it's not commercially relevant" and that "Even watching side-by-side (which no viewer ever does), very few viewers could tell the difference". They also stated that "H.264 has an implementation advantage, not a technology advantage."

    Google's claims that VP8 offers the "highest quality real-time video delivery" and Libvpx includes a mode where the maximum CPU resources possible will be used while still keeping the encoding speed almost exactly equivalent to the playback speed (realtime), keeping the quality as high as possible without lag. On the other hand, a review conducted by streamingmedia.com in May 2010 concluded that H.264 offers slightly better quality than VP8.

    In September 2010 Fiona Glaser, a developer of the x264 encoder, gave several points of criticism for VP8, claiming that its specification was incomplete, and the performance of the encoder's deblocking filter was inferior to x264 in some areas. In its specification, VP8 should be a bit better than H.264 Baseline Profile and Microsoft's VC-1. Encoding is somewhere between Xvid and VC-1. Decoding is slower than FFmpeg’s H.264, but this aspect can hardly be improved due to the similarities to H.264. Compression-wise, VP8 offers better performance than Theora and Dirac. According to Glaser, the VP8 interface lacks features and is buggy, and the specification is not fully defined and could be considered incomplete. Much of the VP-8 code is copy-pasted C code, and since the source constitutes the actual specification, any bugs will also be defined as something that has to be implemented to be in compliance.

    In 2010, it was announced that the WebM audio/video format would be based on a profile of the Matroska container format together with VP8 video and Vorbis audio.

    See also

    References

    External links

    • VP8 Bitstream Guide (specification)
    • The WebM Project
    • Technical Overview Of VP8, An Open Source Video CODEC for the Web - Paper written by Google developers.
    • Fiona Glaser's technical analysis of VP8 esp. as compared to H.264.
    • The VP8 video codec: High compression+low complexity
    • Diary Of An x264 Developer: Announcing the world’s fastest VP8 decoder
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