* fix: don't undercount data channel bitrate over idle gaps
BitrateCalculator divided drained bytes by wall-clock time, including
idle gaps between sparse writes. A fast channel fed sparsely (e.g. 1 KB
every second, acked in a few ms) therefore reported its low offered load
(~8 kbps) instead of its drain capacity (~800 kbps). In the unreliable
writer that shrinks targetLatencyLimit and drops bursts on a channel
that is actually keeping up.
Measure the rate over backlogged ("busy") time only, so idle time no
longer dilutes the estimate. Backlog is detected from the buffer
occupancy just before a write (bufferedAmount - bytesWritten): since no
bytes are added between writes the buffer only drains, so a non-zero
pre-write level means it never emptied and the interval was genuinely
busy. Gating on the post-write buffered amount would be wrong -- it
always includes the just-enqueued (not yet SACKed) bytes and is ~never
zero, collapsing the estimate back to wall-clock. When no backlog is
ever observed the calculator reports no estimate (ok=false) instead of a
confidently-low number.
Introduce BitrateMode:
- BusyOnly (writer default): busy denominator, all drained bytes counted.
- ExcludeIdleDrain: also drops bytes drained across non-backlogged
intervals for a clean drain-capacity estimate free of idle
contamination.
- WallClock: elapsed-time denominator, all bytes; for the test-client
reader which has no send buffer to observe.
Call sites keep the conservative behaviour (writers BusyOnly, reader
WallClock). Tests exercise both writer modes and the mixed idle-then-
backlog window where they diverge.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* Trim comments in data channel bitrate calculator
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
* Make BitrateMode.String a method on the enum
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Some data track related tests are failing due to setting a target
latency of 100ms. Would be good to understand if taget latency or min
buffer is causing the drops.
* fix: bound data-track buffering under downlink congestion
The SFU data-track down-channel writer was constructed with targetLatency=0,
which disables the buffered-amount/latency-based drop in writeUnreliable. Under
subscriber downlink congestion, frames were queued unbounded and in order in the
per-subscriber SCTP send buffer instead of being dropped, so end-to-end latency
grew without limit and only drained once congestion cleared. This contradicts
data tracks being a low-latency, lossy transport.
Wire a dedicated `datachannel_data_track_target_latency` config through to both
data-track writer call sites (mirroring how `datachannel_lossy_target_latency`
controls the lossy publishData channel), reusing lossyDataChannelMinBufferedAmount
as the drop floor. Defaults to 100ms so data tracks are latency-bounded out of
the box; set to 0 to restore the previous unbounded behavior.
Fixes#4666
* fix: track drained bytes on successful unreliable data channel writes
writeUnreliable only called BitrateCalculator.AddBytes when a write failed,
so on the common success path the calculator never received samples. As a
result Bitrate() had no data and the latency-based drop threshold collapsed to
the static minBufferedAmount floor, making the per-subscriber latency control
(datachannel_lossy_target_latency and the new datachannel_data_track_target_latency)
effectively inert. Call AddBytes after every write, matching writeReliable.
* Async attributes on participant.
How it is different from existing participant attributes?
1. Async attribute can be added one at a time.
2. These are not included in `ParticipantInfo`.
3. Get an attribute bt participant identity and async attribute ID as
and when needed.
* clean up
* get full definitions, not just ids
* listener OnDataTrackSchema
* name length config
* data blob
* deps
* static check
* Add missing request ID
* Update protocol commit
* Wire up StoreDataBlobResponse
* Pass request ID through in GetDataBlobResponse
* deps
* atomic
* sctp at 1.9.5
* remove proto clone
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Co-authored-by: Jacob Gelman <3182119+ladvoc@users.noreply.github.com>
This is not all of it as it is not possible (or at least I do not know
of a way) to get all suggestions for a repo/project. Did this via loop
searching mainly and taking the modernize suggestions.
* Thottle the publisher data channel sending when subscriber is slow
Avoid the publisher overwhelm the sfu data channel buffer when
the subscriber has lower receive bitrates. It will drop message
if the subscriber is considered too slow to block the entire room.
* Enable nack in mediaengine and disable it in transceiver as need
pion doesn't support per transciver codec configuration, so the nack of this session will be disabled
forever once it is first disabled by a transceiver.
https://github.com/pion/webrtc/pull/2972
