The Connectivity Standards Alliance (CSA) today released Matter 1.5.1 (link) — a maintenance update to the cross-manufacturer smart home standard that primarily builds on the camera support introduced with version 1.5 in November 2025.
Multi-Stream for More Efficient Connections
The most notable new feature is support for multi-stream video and audio delivery. Previously, separate streams had to be set up for different recipients, such as end devices or ecosystems. With the new capability, a camera can deliver multiple optimized streams simultaneously: a high-resolution feed for recording, a lower-resolution version for mobile devices, and a separate stream for AI-based image analysis. The promise is reduced bandwidth consumption and simpler integrations – at least in theory. How well this holds up across heterogeneous platforms remains to be seen in practice. So far, only Samsung SmartThings has integrated Matter 1.5’s camera features into its ecosystem.
Additional Format Support for Images and Video
Snapshot images can now be delivered in the HEIC format, which offers better image quality at smaller file sizes compared to JPEG. The codec has become standard on newer smartphones, including Apple iPhones (since iOS 11), Samsung devices, and Google Pixel phones. For recorded video, the specification adds full support for HLS and DASH streaming upload via the CMAF Interface-2 profile – formats that are already widely used by cloud and media platforms.
PTZ, Doorbells, Chimes, and Intercoms
Improvements to pan-tilt-zoom (PTZ) behavior bring more flexibility for camera positioning, including setups where the camera’s home position sits at the edge of its rotation range. Doorbells, chimes, and intercom devices also receive updates: chime devices will be able to play a specific ringtone on command from the Matter Controller, rather than simply triggering their default sound. This opens the door for automations that play different tones depending on context – the sound could change based on time of day or season, or indicate which doorbell was pressed when multiple units are installed.
Matter 1.5.1 is not a major feature release. It does what a maintenance update is supposed to do: close gaps and iron out inconsistencies that surfaced during the initial rollout of camera support. The updated specification documents are now available for download on the CSA website.
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