On iPad Brave, a shared video stopped the moment the browser left the
foreground, even with Brave's "Enable Background Audio" on, while an mp3
kept playing. Brave iOS keeps a web <video> going by re-playing one the OS
paused (brave-core ios/browser/web/media/resources/media_backgrounding.ts),
but it only hooks a <video> present at document start or added as a
MutationObserver addedNode that IS a video. React inserts a player's
<video> inside its freshly mounted wrapper in one go, so Brave never saw it.
lib/browserBackgroundPlay re-inserts a mounted <video> at its own position,
once per element: it becomes an added node, the DOM React manages does not
change, and playback is not interrupted. The watch page, the downloads
library player and the Plex player hand their <video> to it. Measured on the
owner's iPad (Brave) with a prototype of the same idea: the video kept
playing in another app and with the screen locked. The YouTube modal is not
ours to change: its <video> lives in YouTube's cross-origin iframe, and
nothing of ours pauses it on backgrounding.
The prototype's two audio-element variants (a muted video following an
<audio>, and an <audio> taking over on hide) went silent in the background on
the iPad and are removed.
The watch page gets a Repeat toggle, on by default and remembered per
browser (LS.watchRepeat; the page has no account): it sets `loop` on the
<video> or the audio-only <audio>.
The player's "still alive" flag — every play() is gated on it, so a late one cannot start a detached
<video> after Back — was only ever LOWERED, in an effect's cleanup. React may run a cleanup and mount
again (StrictMode does exactly that in development), and then the flag stayed false for the life of
the player: it never started by itself, and a seek back past the loaded region, which restarts the
session, left it paused. Found on localdev (Westworld S01E06: playing → seek back → the picture
settles, paused). Production does not double-mount, which is why only dev showed it — and why
several earlier localdev measurements "stayed paused".
The effect now raises the flag in its setup. A new test renders the real player under StrictMode and
checks it plays once the media is ready; red without the fix. Verified on localdev: it starts by
itself, and keeps playing through a backward session-restart seek.
peter