v10/internal/design/spf/features/hevc-variant-selection.md

status, date, definition

status	date	definition
draft	2026-05-20	technical

HEVC variant selection

Select HEVC variants only when the browser and active media pipeline can decode them, while retaining AVC fallback.

Proposed direction

• Filter by codec capability before applying quality policy.
• Prefer HEVC only through explicit policy or a measured efficiency advantage.
• Reuse normal video-track switching when codec transitions are supported.
• Retain a playable AVC path for devices with incomplete HEVC support.

Before implementation

Define codec-string normalization, platform exceptions, changeType requirements, and preference policy. Test HEVC-only, mixed HEVC/AVC, false-positive capability results, and midstream fallback.

Related

Capability probing and rendition selection caps.