Synchronized Playback for YouTube Archived Live Streams

Chrome extension for synchronizing playback across multiple YouTube archived livestream tabs. It adds a `SYNC` control to the YouTube player, lets one tab act as the base timeline, and keeps the other open archived streams aligned with it. ## Features - Synchronize multiple YouTube archived livestream - Choose a base tab that drives playback position, pause state, and playback speed - Apply a per-tab offset in seconds to fine-tune alignment - Switch between two sync modes: - `Sync with the actual broadcast time` - `Sync with the video timestamp` - Shows an out-of-range warning when a target stream cannot seek to the requested position ## Usage 1. Open the YouTube archived livestream pages you want to synchronize 2. Press `SYNC` on each page you want to include 3. The first tab where you press `SYNC` automatically becomes the `BASE` tab 4. If you want a different tab to control the group, click the active `SYNC` button on that tab once more so it becomes `BASE` 5. If the current `BASE` tab is closed, one of the other synchronized tabs is automatically promoted to become the new `BASE` 6. Optionally adjust each tab's offset value in seconds 7. Use the menu on the base tab to switch between broadcast-time sync and timestamp sync ## Sync Modes ### Actual broadcast time Best for comparing separate archives of the same live event from different channels or perspectives. This mode synchronizes videos based on the real-world broadcast time derived from the video metadata and current playback position. ### Video timestamp Best when you want all tabs to match the visible player timestamp directly. This mode synchronizes videos using each video's current playback timestamp.