Mozilla Is Interested In A Rust JPEG-XL Decoder For Firefox & Google Might Develop It

Mozilla is interested in a Rust-written JPEG-XL image decoder for its memory safety characteristics compared to the existing C++ code they rely on for JPEG-XL image support in Firefox. While Google previously removed JPEG-XL support from Chrome/Chromium, it may be Google that comes to the rescue and writes a Rust-based JPEG-XL image decoder that can then be shipped by Firefox.

Bobby Holley as the CTO of Firefox at Mozilla laid out their position yesterday for backing a possible Rust-based JPEG-XL image decoder for Firefox. To the Mozilla standards positions repository he commented in a new pull request "Firefox will consider a Rust implementation of JPEG-XL" with the following explanation:

"Over the past few months, we’ve had some productive conversations with the JPEG-XL team at Google Research around the future of the format in Firefox. Our primary concern has long been the increased attack surface of the reference decoder (currently behind a pref in Firefox Nightly), which weighs in at more than 100,000 lines of multithreaded C++. To address this concern, the team at Google has agreed to apply their subject matter expertise to build a safe, performant, compact, and compatible JPEG-XL decoder in Rust, and integrate this decoder into Firefox. If they successfully contribute an implementation that satisfies these properties and meets our normal production requirements, we would ship it.

Time will tell whether the format succeeds in becoming a universal JPEG replacement in the way some folks hope. In the event that it does, it would be unfortunate to potentially introduce memory safety vulnerabilities across the myriad of applications that would eventually need to support it. A safe, fast, and battle-tested Rust decoder from the original team could make that scenario much less likely, and so we’re using our leverage to encourage progress on this front."

Very interesting, especially considering the past history of JPEG-XL and Chrome. But if Google invests in writing a Rust-based JPEG-XL decoder, it will be interesting to see if they go ahead in reconsidering their image support within Chrome. Otherwise it would be rather ironic if Google develops this Rust-based JPEG-XL decoder only to be used by Firefox and other non-Google software.

In any case we'll see what comes up on this front over the coming months.