* Remove `Head` field from `ExtPacket` structure.
Although we do not intend to, but if packets get out-of-order
in the forwarding path (maybe reading in multiple goroutines
or using some worker pool to distribute packets), the `Head`
indicator could lead to wrong behaviour. It is possible that
at the receiver, the order is
- Seq Num N, Head = true
- N + 1, Head = true
If the forwarding path sees `N + 1` first, the Head flag
when it sees `N` packet is incorrect and will lead to incorrect
behaviour.
The alternative check is very simple. So, remove `Head` flag.
* Remove unused field
* Use delta stats throughout and avoid calculating deltas in telemetry
* Fix a few things after testing
* Remove debug
* Fix tests
* delete instead of setting to nil
* Point to the latest protocol
* Handle an edge in layer lock.
A very edge case
- Available layer: [0, 1, 2], but bitrate is not yet available.
We set it to layer 2 awaiting measurement.
- Measurement for layers 0 and 1 come through.
- Still no key frame for layer 2.
- Finalize layers runs and sees that bitrate is available for 0 and 1.
It finalizes layer 1.
- Layer 1 key frame comes (because we asked key frame of layer 2,
publisher sends key frame for all layers). Locks to layer 1.
- No more events happen to switch to layer 2.
Changes
-------
- Move bit rate measurement to StreamTrackerManager. Allows re-use
in relay.
- Make bit rate availability (from zero -> non-zero) an event
and let it flow through the stream allocation flow so that we
always have an event when bit rate measurement becomes available.
This gets rid of finalization which I was unhappy with it anyway as
it was polling every second.
- Removing REMB stuff from buffer. We do not use it.
It is incorrect anyway. REMB should be ay peer connection level.
* Fix test
* fix test
* Simplify allocate
* Simplify/clean up
This still does not address root cause of large loss, but at least
does not display crazy thing like packets = 0, but packet rate is 45/s.
Also, RLock in ToString() as there are bits of structure used in
stringification.
* Key frames
- Keep track of key frame stats
- Split out PLI from down track used for purpose of layer locking.
This will give us a good picture of down stream issues forcing a PLI.
- Use key frame requester whenever there is a layer lock required.
Not just the first key frame. With the synchronous thing, the counter
was just ridiculously high like 150 or something because of all
the initial padding packets. Also, use RTT in key frame requester.
* send first PLI before waiting
* Turn off key frame requester when disabled
* simplify
* Introducing OpsQueue
Creating a PR to get feedback on standardizing on this concept.
Can be used for callbacks.
Already a couple of places use this construct. Wondering if we
should standardize on this across the board.
Just changing one place to use the new struct. Another place
that I know of which uses this pattern is the telemetry package.
* atomic flag -> bool
* Consolidating PLI throttle
Use the throttler in `sfu.WebRTCReceiver`.
Does change shape of config object.
* Move PLIThrottleConfig to sfu.WebRTCReceiver
* fix test compile
* Cleaning up unused stuff
* readability improvement
RTCP messages are going through two channel hops now.
Maybe we don't need that anymore now that the original
problem is diagnosed. But, pushing all RTCP via
the callbackOps channel for now to make it consistent.
