From Collabora | Open Source Consulting · · 3m
How YouTube Got a New Engine for the TV
Collabora spent a year porting Google's Chromium-based YouTube engine onto RDK set-top hardware, and it now ships as the reference design.
In brief
Collabora spent a year porting Google's Chromium-based YouTube engine onto RDK set-top hardware, and it now ships as the reference design. Cobalt's rewrite on top of Chromium only mattered to TV makers once someone proved it ran on real RDK silicon, and that proof is now public. Originally reported by Collabora | Open…
Check your TV's app version
Open YouTube on a smart TV, go to Settings then App Version. A string like 25.lts tells you which engine is rendering the app behind the glass.
“you might spot a version text like 25.lts”
Cobalt was built small
Google wrote Cobalt as a stripped-down HTML5, CSS and JavaScript engine for TVs and set-top boxes, machines with too little RAM and CPU to host full Chromium.
Starboard is the hardware seam
Cobalt talks to silicon through an abstraction layer called Starboard. That layer is what lets OEMs and chip vendors port YouTube onto their own custom hardware.
A separate engine got expensive
Keeping an independent layout and rendering engine in step with the modern web is a huge ongoing cost, especially as security fixes land upstream in Chromium every few weeks.
“maintaining an independent layout and rendering engine alongside the rapidly evolving modern web ecosystem is a massive undertaking”
Enter Chrobalt
Google merged Cobalt's code into Chromium. The result is a Chromium embedder that keeps the Starboard porting layer, shipping as 26.eap and now 27.lts on Chromium 138 and later.
“Merge Cobalt's code with Chromium to get a robust, standard-compliant rendering pipeline.”
Both worlds at once
Device makers get upstream web features and fast security updates, plus the lean media pipelines a TV or set-top box actually needs to stay inside its memory budget.
The missing reference port
Chrobalt had reference ports for desktop and Android. Neither convinces a TV manufacturer, who needs to see it running on the kind of board they actually ship.
A year on Amlogic
Collabora worked with Google's Cobalt and partner engineering teams to port and stabilize Chrobalt on an RDK platform for Amlogic chipsets, aimed at partners like Samsung and LG.
Rebuilding the toolchain
Legacy Starboard recipes across RDK's Yocto layers were pulled apart and restructured, and the toolchains modernized to the newer C++ standards Chromium demands.
Proving it with tests
They wired in Chromium's unit tests alongside Starboard's NPLB conformance suite, then passed the YouTube Test Suite for 4K playback, DRM handling and low-latency input.
Driving the device over DAB
YTS runs are automated through the Device Automation Bus. Collabora co-authored the Rust reference implementation and fixed its adapter so full test runs were reproducible.
Named in Japan
At April's YouTube Device Partner Summit, the Chrobalt RDK reference platform was presented to industry partners as a production-ready path for the next generation of TVs.
“a validated, production-ready path forward for next-generation living room deployments”
Here's the gist
Cobalt's rewrite on top of Chromium only mattered to TV makers once someone proved it ran on real RDK silicon, and that proof is now public.
