USB and Bluetooth audio driver reference

Transport shapes the first layer

USB audio devices expose descriptors, interfaces, endpoints, and transfer contracts through a bus topology. Bluetooth audio uses a wireless stack, device roles, profiles, and transport channels. Both can present playback and capture functions, but their identity and lifecycle records are not identical.

Audio functions sit above transport

A transport driver or class layer carries data and control messages, while an audio component represents streams, formats, and endpoints. A product’s marketing name can hide several interfaces and profile relationships. The useful noun is the layer being described.

Profiles and formats are contracts

Bluetooth profiles describe roles and service behavior, while audio stream formats describe samples, channels, timing, and encoding at an audio boundary. USB descriptors describe interfaces and endpoints. None of those records alone is a complete product specification.

Lifecycle and trust remain separate

Enumeration, pairing or discovery, interface matching, package selection, endpoint publication, and stream negotiation have distinct owners. Package signing and version fields describe host software; device firmware and profile records have their own scope.

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