v10/internal/design/spf/features/capability-probing.md

status, date, definition

status	date	definition
partial	2026-05-20	sketched

Capability probing

Determine whether the current browser can play a candidate track before selection or append.

Implemented

Codec filtering is available through canPlayTrack and excludeUnplayableTracks. The current HLS composition uses those primitives before track resolution.

Remaining scope

• Key-system compatibility for encrypted tracks.
• SourceBuffer.changeType() support and transition constraints.
• Optional segment-level probing where manifest codecs are insufficient.
• Actionable errors when every candidate is rejected.

Current sources

• packages/spf/src/media/primitives/can-play-track.ts
• packages/spf/src/playback/behaviors/track-switching.ts
• colocated tests

Add new probes only when a consuming selection or append workflow has a concrete need.