The Player page can be seeded with named, fully-formed configurations via a ?presets= URL parameter — handy for sharing reproducible setups. This builder assembles that link for you.

• Add one or more presets; each needs a name (the selector label) — every other field is optional.
• The link uses URL-safe base64, so it pastes anywhere without truncation or encoding.
• Opening it shows a Predefined Configurations selector on the Player page and auto-loads the first preset.
• Pre-roll is a full on/off toggle: leave it off and the preset injects no pre-roll.
• Unknown keys / enum values are ignored (forward-compatible). It's a demo convenience — no SDK/core change.