Google's new squeeze: Brotli compression open-sourced

Chocolate Factory turns Pied Piper to Deflate expectations


Google wants to bring to life the HBO series Silicon Valley: it's pitching a new open source compression algorithm into the world, with the hope that it can eventually end-of-life the venerable Deflate.

Brotli (“small bread” in Swiss German, apparently) follows on from Zopfli (“little braid,” also bread-themed), but with between 20 and 26 per cent better compression ratios.

That, software engineer Zoltán Szabadka of Google's Compression Team writes, is because while Zopfli maintained Deflate compatibility, Brotli uses new data structures.

Szabadka lists the key changes as “a 2nd order context modeling, re-use of entropy codes, larger memory window of past data, and joint distribution codes.”

In this paper, Szabadka and collaborators Jyrki Alakuijala, Evgenii Kliuchnikov, and Lode Vandevenne also explain that Brotli adds a static dictionary to the compression algorithm:

“It contains 13,504 words or syllables of English, Spanish, Chinese, Hindi, Russian, and Arabic, as well as common phrases used in machine readable languages, particularly HTML and JavaScript. The total size of the static dictionary is 122,784 bytes. The static dictionary is extended by a mechanism of transforms that slightly change the words in the dictionary. A total of 1,633,984 sequences, although not all of them unique, can be constructed by using the 121 transforms.”

In tests under Linux 3.13.0 on an Intel Xeon Eg-1650 v2 machine running at 3.5 GHz, the researchers claimed Brotli running at 3.381:1 compression ratio could compress at 98.3 MB/s and decompress at 334 MB/s.

The fastest Deflate could run at a low-quality setting of 2.913:1 compression was 93.5 MB/s compression and 323 MB/s decompression.

Google notes that better compression would particularly benefit mobile users, who in addition to faster page loads would get savings on their data charges and hopefully lower battery consumption.

And, of course, if Brotli is a success, there's no chance that Google will end up torching a basement.

The Register would note that Deflate's endurance demonstrates just how effective the original work was: it was described in RFC 1951 in 1996.

Brotli is on GitHub here. ®

Broader topics


Other stories you might like

  • Experts: AI should be recognized as inventors in patent law
    Plus: Police release deepfake of murdered teen in cold case, and more

    In-brief Governments around the world should pass intellectual property laws that grant rights to AI systems, two academics at the University of New South Wales in Australia argued.

    Alexandra George, and Toby Walsh, professors of law and AI, respectively, believe failing to recognize machines as inventors could have long-lasting impacts on economies and societies. 

    "If courts and governments decide that AI-made inventions cannot be patented, the implications could be huge," they wrote in a comment article published in Nature. "Funders and businesses would be less incentivized to pursue useful research using AI inventors when a return on their investment could be limited. Society could miss out on the development of worthwhile and life-saving inventions."

    Continue reading
  • Declassified and released: More secret files on US govt's emergency doomsday powers
    Nuke incoming? Quick break out the plans for rationing, censorship, property seizures, and more

    More papers describing the orders and messages the US President can issue in the event of apocalyptic crises, such as a devastating nuclear attack, have been declassified and released for all to see.

    These government files are part of a larger collection of records that discuss the nature, reach, and use of secret Presidential Emergency Action Documents: these are executive orders, announcements, and statements to Congress that are all ready to sign and send out as soon as a doomsday scenario occurs. PEADs are supposed to give America's commander-in-chief immediate extraordinary powers to overcome extraordinary events.

    PEADs have never been declassified or revealed before. They remain hush-hush, and their exact details are not publicly known.

    Continue reading
  • Stolen university credentials up for sale by Russian crooks, FBI warns
    Forget dark-web souks, thousands of these are already being traded on public bazaars

    Russian crooks are selling network credentials and virtual private network access for a "multitude" of US universities and colleges on criminal marketplaces, according to the FBI.

    According to a warning issued on Thursday, these stolen credentials sell for thousands of dollars on both dark web and public internet forums, and could lead to subsequent cyberattacks against individual employees or the schools themselves.

    "The exposure of usernames and passwords can lead to brute force credential stuffing computer network attacks, whereby attackers attempt logins across various internet sites or exploit them for subsequent cyber attacks as criminal actors take advantage of users recycling the same credentials across multiple accounts, internet sites, and services," the Feds' alert [PDF] said.

    Continue reading

Biting the hand that feeds IT © 1998–2022