Make changing to HAVE_ENOUGH_DATA ready state specification complaint #40740
Description
Describe the bug:
Currently changing ready state of the media element to HAVE_ENOUGH_DATA happens in one possible case if
the media player state is PlaybackState::Paused and ready state is HAVE_METADATA.
https://html.spec.whatwg.org/multipage/media.html#dom-media-have_metadata
https://html.spec.whatwg.org/multipage/media.html#dom-media-have_enough_data
fn playback_state_changed(&self, state: &PlaybackState) {
let mut media_session_playback_state = MediaSessionPlaybackState::None_;
match *state {
PlaybackState::Paused => {
media_session_playback_state = MediaSessionPlaybackState::Paused;
if self.ready_state.get() == ReadyState::HaveMetadata {
self.change_ready_state(ReadyState::HaveEnoughData);
}
},
...
}
Need to figure out how to remove gstreamer dependency from the media element carefully and based it on buffering state of the media source?!
https://html.spec.whatwg.org/multipage/media.html#event-media-canplaythrough
For now it works due to some undocumented functionality in servo-media source code
https://github.com/servo/media/blob/main/backends/gstreamer/player.rs#L604
This gst_play_set_rate triggers the unexpected (unnecessary) seek request to current pipeline position (0.0) and changing player state from paused to buffering to paused (the latest one event allows the media element to set ready state to HAVE_ENOUGH_DATA).
Note that changing playback rate make new seek request to current position with new value (with seek completion event afterwards).
gst_play_set_rate
gst_play_set_rate_internal
0:02.62 pid:3989830 HTMLMediaElement (0x7fa1a76c2500) create_media_player gen_id = 1
0:02.62 pid:3989830 GST connect_state_changed: player_state = Buffering
0:02.62 pid:3989830 HTMLMediaElement fetch_request.url = "http://web-platform.test:8000/media/movie_5.mp4?Wed%20Nov%2019%202025%2016:08:30%20GMT+0300%20(Moscow%20Standard%20Time)0.025068950373179355"
0:02.62 pid:3989830 process_response request_id = RequestId(4c040425-65d4-4141-9002-4fd6fba7d41c
0:02.62 pid:3989830 process_response_eof request_id = RequestId(4c040425-65d4-4141-9002-4fd6fba7d41c) fetched_content_length = 31603
0:02.62 pid:3989830 GST connect_state_changed: player_state = Paused
0:02.68 pid:3989830 GST connect_media_info_updated + SET_RATE
0:02.68 pid:3989830 GST connect_duration_changed: duration = Some(0:00:05.153333333)
0:02.68 pid:3989830 HTMLMediaElement (0x7fa1a76c2500) change_ready_state [HaveNothing -> HaveMetadata]
0:02.68 pid:3989830 GST connect_state_changed: player_state = Buffering
0:02.68 pid:3989830 GST connect_seek_done: position = 0:00:00.000000000
0:02.68 pid:3989830 GST connect_state_changed: player_state = Paused
0:02.68 pid:3989830 HTMLMediaElement (0x7fa1a76c2500) change_ready_state [HaveMetadata -> HaveEnoughData]
To Reproduce:
Run the following test
./mach test-wpt tests/wpt/tests/html/semantics/embedded-content/media-elements/event_timeupdate_noautoplay.html -r --log-mach=-
Platform:
Ubuntu 22.04