* Support XR request/response for rtt calculation
* Update pkg/sfu/downtrack.go
Co-authored-by: David Zhao <dz@livekit.io>
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Co-authored-by: David Zhao <dz@livekit.io>
* Remove subscriber if track closed while adding subscriber.
It is possible that the track is closed when subscriber add is
processed. That subscriber would have been dangling off a closed track.
Check again after adding subscriber if track is closed.
If it is, remove the subscriber and return error so that subscription
manager re-resolves.
* oops, wrong unlock
When a fallback is not applied, it is due to signal interruption.
ICE connection failing happens. And every time there is error, it is due
to "no selected pair".
Move all of it to `Debugw`. `setting ICE config` is the definitive log
which says if a different ICE config was applied.
* Maintain subscription count.
Does not affect function as it is not decremented only if limits are
configured. But, good to maintain proper count anyway.
* wire
Simplify a bit. Pending migratiion tracks need not be maintained as when
a migrated track is added, it is added to up track manager and treated
as a published track. When up track manager closes, published tracks
will close. So, no need to maintain a separate list.
* Buffer size config for video and audio.
There was only one buffer size in config.
In upstream, config value was used for video.
Audio used a hard coded value of 200 packets.
But, in the down stream sequencer, the config value was used for both
video and audio. So, if video was set up for high bit rate (deep
buffers), audio sequencer ended up using a lot of memory too in
sequencer.
Split config to be able to control that and also not hard code audio.
Another optimisation here would be to not instantiate sequencer unkess
NACK is negotiated.
* deprecate packet_buffer_size
* Reduce heap for dependency descriptor in forwarding path.
Marshaled dependency descriptor is held in sequencer adding heap objcts.
Store DD bytes in sequencer to avoid heap usage.
Also, accomodating over sized objects via storing in slice and using it
in case the bytes do not fit in the internal array.
NOTE: Marshal DD still does a make([]byte...), but I think it should be
on the stack given the short use of it. Have to verify.
* fix test and also add cases for oversized codec/dd bytes
It is possible that participant state and migration state updates are
racing. And a participant update could end up with no tracks when
migration is being processed.
Moving handling of migrated tracks to when the migration state moves to
completed. Pending data channel were already happening only on complete.
Move tracks also to that point.
Handling it earlier meant that track published callback happened and
ownership of track moved to new node before the new node could finish
peer connection. So, in cases where migration did not go through, this
caused confusion of track ownership.
