Till now only video was using simulated publish when migrating on mute.
But, with `pauseUpstream() + replaceTrack(null)`, it is possible that
client does not send any data when muted.
I do not think there is a problem to do this (even when cleint is
actually using mute which sends silence frames).
If ref is coming in slow (due to pacing), it is possible that
expected is ahead. Pulling next too far towards expected causes
warps in a subsequent report. Keep switches closer to ref.
On a state change, it was possible an aborted probe was pending
finalize. When probe controller is reset, the probe channel
observer was not reset. Create a new non-probe channel observer
on state change to get a fresh start.
Also limit probe finalize wait to 10 seconds max. It is possible
that the estimate is very low and we have sent a bunch of probes.
Calculating wait based on that could lead to finalize waiting for
a long time (could be minutes).
* Simplify probe done handling.
Seeing a case where the channel abserver is not re-created after
an aborted probe. Simplifying probe done (no callbacks, making it
synchronous).
* log more
* Use receiver report stats for loss/rtt/jitter.
Reversing a bit of https://github.com/livekit/livekit/pull/1664.
That PR did two snapshots (one based on what SFU is sending
and one based on combination of what SFU is sending reconciled with
stats reported from client via RTCP Receiver Report). That PR
reported SFU only view to analytics. But, that view does not have
information about loss seen by client in the downstream.
Also, that does not have RTT/jitter information. The rationale behind
using SFU only view is that SFU should report what it sends irrespective
of client is receiving or not. But, that view did not have proper
loss/RTT/jitter.
So, switch back to reporting SFU + receiver report reconciled view.
The down side is that when receiver reports are not receiver,
packets sent/bytes sent will not be reported to analytics.
An option is to report SFU only view if there are no receiver reports.
But, it becomes complex because of the offset. Receiver report would
acknowledge certain range whereas SFU only view could be different
because of propagation delay. To simplify, just using the reconciled
view to report to analytics. Using the available view will require
a bunch more work to produce accurate data.
(NOTE: all this started due to a bug where RTCP was not restarted on
a track resume which killed receiver reports and we went on this path
to distinguish between publisher stopping vs RTCP receiver report not
happening)
One optimisation to here here concerns the check to see if publisher is sending data.
Using a full DeltaInfo for that is an overkill. Can do a lighter weight
for that later.
* return available streams
* fix test
* Perform unsubscribe in parallel to avoid blocking
When unsubscribing from tracks, we flush a blank frame in order to prepare
the transceivers for re-use. This process is blocking for ~200ms. If
the unsubscribes are performed serially, it would prevent other subscribe
operation from continuing.
This PR parallelizes that operation, and ensures subsequent subscribe
operations could reuse the existing transceivers.
* also perform in parallel when uptrack close
* fix a few log fields
* Avoid reconnect loop for unsupported downtrack
If the client subscribes to a track which codec is unsupported by the
client, sfu will trigger negotiation failed and issue a full reconnect
after received client answer. If the client try to subscribe that track
then it will got full reconnect again. That will cause a infinite
reconnect loop until the client don't subscribe that track. This PR
will unsubscribe the error track for the client and send a
SubscriptionResponse that contain the reason to indicates the track's
codec is not supported to avoid the reconnect loop.
Because we aren't able to get CPU count/load info on Windows, they are
stubbed out to return placeholders. This restores compatibility to run
on Windows.
* Split probe controller from StreamAllocator.
With TWCC, there is a need to check for probe status
in a separate goroutine. So, probe specific stuff need
locking. Split out the probe controller to make that cleaner.
* remove defer
* Return max spatial layer from selectors.
With differing requirements of SVC and allowing overshoot in Simulcast,
selectors are best placed to indicate what is the max spatial layer when
they indicate a switch to max spatial layer.
* fix test
* prevent race
It is possible that publisher paces the media.
So, RTCP sender report from publisher could be ahead of
what is being fowarded by a good amount (have seen up to 2 seconds
ahead). Using the forwarded time stamp for RTCP sender report
in the down stream leads to jumps back and forth in the down track
RTCP sender report.
So, look at the publisher's RTCP sender report to check for it being
ahead and use the publisher rate as a guide.
Actually, was not filtering the not last sender report error before.
Previous PR did that. This PR restores the old no last sender report
filter. Both are filterable errors.
Raja Subramanian