* Do not block on down track close with flush.
When publisher removes all subscribers, publisher side should
not be blocked for long. With close with flush, it could happen
if there a lot of bunch of subscribers.
So, when is expected, run it in a goroutine like it is done in
subscription manager.
Not moving the entire `RemoveSubscriber` bit to subscription manager as
there are two bits which are not tracked now
- mime type
- willBeResumed
Those two would have to be tracked in track manager and notified to
subscription manager so that it can act for that mine and if the track
will be resumed or not. As that touch more parts and could get
complicated, doing the simpler thing of cloning behaviour from
subscription manager for now.
* clean up
* code readability
* Do server PLI when sync is required.
A few changes
- Run key frame requester goroutine always. Runs every 200 ms which is
not bad.
- Post a key frame request when server knows it needs one, like after an
allocation. This ensures that the initial request is not delayed.
- Periodic check will ensure PLI for cases like all frame chains of a
dependency descriptor being broken.
* simplify
* Disable H.264 for android firefox
* Fix syntax error for rule
* lower case
* Remove disabled codec from AddTrackRequest
* Consistent handling of enabled codecs
Mainly cleaning up where we are doing codec filtering.
There's also behavior change of how we handle codec compatibility. If a client doesn't support the client's desired codec, we'll pick a backup automatically
instead of rejecting the client's request.
Requires an update on multi-codec simulcast handling.
* fix alternative codec selection
---------
Co-authored-by: David Zhao <dz@livekit.io>
A few things
- Log PLI requests from client.
- Pass in marker to RTP munger as SVC can insert marker.
- Adjusting first packet time should be aware of SVC as there is single
stream in SVC
When starting from scratch (like mute -> unmute), it is possible
that the check sync does not detect a broken chain. That results
in PLIs not being sent and the video frozen till a gratuitous key
frame arrives.
Unclear why there are not PLIs from client side. That is something else to
dig into.
SVC has only one stream and when calculating reference time stamp,
irrespective of reference layer, reference time stamp will be the
same as the given time stamp as there is only one stream and no offset.
TODO: Need better all around SVC handling.
The buffer is not for padding packets. So, calculate
adjusted sequence numbers before comparing against size.
Also, it is possible that invalidated slot is accessed
due to not being able to exclude padding range. This was
causing time stamp reset to 0. Will remove the error log
after this goes out and the condition does not show up
for a few days.
* Remove un-preferred codecs for android firefox
Android firefox don't comply with the codec order in answer sdp and
has problem to publish h.264, remove other codecs to fix this.
* false(false) is true
* Fix deadlock
My previous PR to wrap layer notifier post in bind lock was
problematic as `onBinding` callback happens within that lock
and that onBinding callback can call set max layer which will
post to channel. Use a separate mutex.
* RUnlock
* Do not post to closed channels.
Perils of atomics. Hard to imagine, but I guess it could happen.
The postMaxLayerNotifier checked for closed and down track was not
closed. But, between that check and posting to channel (which is
a very small window), the down track could have been closed and
the channel (maxLayerNotiferCh) is closed.
Protect that channel post + close with the bind lock.
* reduce the change
* Check for closed inside lock
The probing + munging has not been set up to drop packets that follow
a gap. Dropping such a packet leads to padding packet sequence numbers
overlapping with regular packets.
This change does two things though.
- The not relevant packet will still not be sent over the wire. That could
create holes in the sequence number leading to NACKs
- Would the hole cause decode issues? Unclear as making this condition is hard.
Simulating it is not showing issues, but that may not be producing the bad
sequence if any.
Will look at the ability to drop a packet after a gap later.
Seeing a time stamp jump that I am not able to explain.
Basically, it looks like the time stamp doubles at some
point. There is no code which doubles the timestamp.
Can understand an erroneous roll over/wrap around, but
doubling is very strange.
So, logging only audio packets. Will disable as soon
as I have some smaples from canary.
Seeing some unexplained jumps in sender report time stamp
in canary. Wonder if the calculated clock rate is way off
during some interval. Logging clock deviations to understand
better.
* More fine grained filtering NACKs after a key frame.
There are applications with periodic key frame.
So, a packet lost before a key frame will not be retransmitted.
But, decoder could wait (jitter buffer, play out time) and cause
a stutter.
Idea behind disabling NACKs after key frame was another knob to
throttle retransmission bit rate. But, with spaced out retransmissions
and max retransmissions per sequence number, there are throttles.
This would provide more throttling, but affects some applications.
So, disabling filtering NACKs after a key frame.
Introducing another flag to disallow layers. This would still be quite
useful, i. e. under congestion the stream allocator would move the
target lower. But, because of congestion, higher layer would have lost
a bunch of packets. Client would NACK those. Retransmitting those higher
layer packets would congest the channel more. The new flag (default
enabled) would disallow higher layers retransmission. This was happening
before this change also, just splitting out the flag for more control.
* split flag
* Log skew in clock rate.
Remember seeing sender report time stamp moving backward
across mute with replaceTrack(null). Not able to reproduce
it in JS sample app, but have seen it elsewhere.
Logging to understand it better. Wondering if the sender report
should be reset on time stamp moving backward or if we should drop
backwards moving reports.
* set threshold at 20%
Paul Wells