Table of Contents

Windows 11 CAPX Feature

Yes, definitely! Windows 11 is now available with a new framework called Core Audio Processing Extensions (CAPX), which is one of the key features with respect to Windows audio processing. But, what is the purpose of introducing this new framework? Will it aid Windows users in improving their audio experience, if yes, how?

Should you upgrade to Windows 11?

Yes, definitely! Windows 11 is now available with a new framework called Core Audio Processing Extensions (CAPX), which is one of the key features with respect to Windows audio processing. But, what is the purpose of introducing this new framework? Will it aid Windows users in improving their audio experience, if yes, how?

Windows 11 CAPX Framework

Microsoft has introduced a new framework Core Audio Processing Extensions (CAPX) APIs for Audio Processing Objects (APOs), and several requirements with Windows 11 OS release. CAPX settings framework is only way to communicate between APO & Hardware Support App (HSA) and registry key access (Read/write) for processing the audio effects. Under this feature, there are additional APIs, which are available starting in build 22000 of Windows.

Advantages of these added APIs are to enable different scenarios for HSA applications, improve overall audio performance and ease in debuggability with respect to the development. These new audio settings API is designed for OEMs and HSA developers who are interested in querying and altering the audio effects settings associated with an audio device. To provide access to the property store, framework API is made available to both HSA and Win32 applications. This behavior is highly favored by end users due to the fact that it preserves the changes they have made to the system over time which does not lose on OS upgrade and preserves again on audio application launch.

msft-capx-framework-for-render-apo-block-diagram

New FxProperty Property Store

A few more subkeys Default, User, and Volatile have been added to the property store in this latest update. The saved audio settings from these subkeys can be accessed by HSA apps when initializing the application using the latest APO APIs.

During the upgrade of the OS to Windows 11, custom registry entries are created under the registry path HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio to store audio settings. If user settings are not properly migrated to the new framework settings during an OS upgrade, it can result in poor audio quality or no audio at all.

Previous registry layout for this framework (also known as audio property store)

Windows 10 Audio Registry Layout

On OS upgrade to Windows 11, it modifies to below property store:

 

Windows 11 Audio Registry CAPX Layout

The Default subkey will have custom effects properties generated from vendors audio installer and will not persist on OS upgrade. The User subkey will have user settings as per the audio effects settings to be executed and will be persistent on OS upgrade, which means it will carry/copy the same settings from this property key to the new APO context Id after OS upgrade. The Volatile subkey will have the volatile properties setting and will be lost on device reboot. Each time the endpoint goes active, it will be cleared out.

Conclusion

Windows 11’s Core Audio Processing Extensions (CAPX) framework revolutionizes audio processing. Featuring APIs for Audio Processing Objects (APOs) and an advanced FxProperty Property Store, it ensures a smooth OS upgrade, preserving user settings and preventing audio issues. Tailored for OEMs and HSA developers, these APIs enhance audio scenarios and simplify debugging.

Upgrade now for a cutting-edge audio experience that seamlessly combines performance, flexibility, and user customization.

Picture of Kiran Mandhare

Kiran Mandhare

Kiran is working as a Technical Lead at eInfochips. He has a total of 13 years of experience, concentrating on the development of Windows based applications. Architecting and developing network audio solutions, including applications, middleware, and audio drivers, that can be integrated on Windows Platform. He graduated in Information Technology Engineering from Pune. In his free time, he likes to listen music and trekking.

Explore More

Talk to an Expert

Subscribe
to our Newsletter
Stay in the loop! Sign up for our newsletter & stay updated with the latest trends in technology and innovation.

Reference Designs

Our Work

Innovate

Transform.

Scale

Partnerships

Device Partnerships
Digital Partnerships
Quality Partnerships
Silicon Partnerships

Company

Products & IPs