Phase 3c mirrors Phase 3b on the Android receive path. With Phase 0-3b
landed on desktop + Android encoder, this commit completes codec-layer
loss recovery on the Android decoder side.
Architectural difference vs desktop: engine.rs has NO jitter buffer.
The recv task reads packets directly from the transport via
recv_media().await and writes decoded audio straight into the playout
ring. There is no PlayoutResult::Missing equivalent. Gap detection
therefore has to be done via sequence-number tracking — when a packet
arrives with seq > expected_seq, the frames in between are missing and
we attempt to reconstruct them via DRED before decoding the newly-
arrived packet.
Implementation:
Imports & types:
- Added wzp_codec::AdaptiveDecoder, wzp_codec::dred_ffi::{
DredDecoderHandle, DredState} imports.
- Changed the `decoder` local from Box<dyn AudioDecoder> (via
wzp_codec::create_decoder) to concrete AdaptiveDecoder::new(profile).
Same reasoning as Phase 3b: reconstruct_from_dred is an inherent
method, not a trait method, so we need the concrete type.
Recv task state (all task-local, no new struct fields):
- dred_decoder: DredDecoderHandle
- dred_parse_scratch: DredState (reused, overwritten per parse)
- last_good_dred: DredState (cached most-recent valid state)
- last_good_dred_seq: Option<u16>
- expected_seq: Option<u16> (for gap detection)
- dred_reconstructions: u64 (telemetry)
- classical_plc_invocations: u64 (telemetry)
Recv loop body (Opus source packets only):
1. Parse DRED from the new packet first so last_good_dred reflects
the freshest state available for gap recovery.
2. Detect a gap: gap = pkt.seq.wrapping_sub(expected_seq). Cap at
MAX_GAP_FRAMES = 16 (320 ms) to avoid huge wraparound scenarios.
3. For each missing seq in the gap:
offset = (last_good_dred_seq - missing_seq) * frame_samples
if 0 < offset <= last_good_dred.samples_available():
reconstruct_from_dred + write to playout ring
bump dred_reconstructions
else:
decoder.decode_lost (classical PLC) + write + bump plc counter
4. Decode the current packet normally and write to playout ring
(unchanged from Phase 2).
5. Update expected_seq = pkt.seq.wrapping_add(1).
Profile-switch handling: when the incoming codec changes (triggering
decoder.set_profile), reset last_good_dred_seq and expected_seq to
None. The cached DRED state is tied to the old profile's frame rate
and would produce wrong offsets after the switch; starting fresh is
correct.
Decode-error fallback: the existing `Err(e) => decode_lost` branch
now also increments classical_plc_invocations so the counter
accurately reflects all PLC invocations (gap-detected AND decode-
error-triggered).
Telemetry (CallStats additions):
- stats.dred_reconstructions: u64
- stats.classical_plc_invocations: u64
Both updated on every packet arrival in the existing stats.lock()
block alongside frames_decoded/fec_recovered, so the Android UI and
JNI bridge already have these values without any further plumbing.
The periodic recv stats log now includes both counters.
Ordering note: DRED gap reconstruction happens BEFORE decoding the new
packet's audio because the playout ring is FIFO. Gap samples must be
written before the new packet's samples so temporal order is preserved.
Out-of-order late arrivals (seq < expected_seq) are naturally dropped
as stale by the gap detection (gap would be a large wraparound value
exceeding MAX_GAP_FRAMES).
Verification:
- cargo check --workspace: zero errors
- cargo test -p wzp-codec --lib: 68 passing (unchanged from Phase 3b)
- cargo test -p wzp-client --lib: 35 passing (unchanged from Phase 3b)
- cargo check -p wzp-android --lib: zero errors
- cargo test -p wzp-android cannot run on macOS host (pre-existing
-llog linker dep, unrelated). Real end-to-end verification happens
via the Android APK build on the remote Docker builder
(scripts/build-and-notify.sh).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Three fixes for 3-relay chain (R1→R2→R3):
1. Room lookup in handle_datagram: hub relay (R2) has no local
participants, so active_rooms() was empty and datagrams were
silently dropped. Now also checks global_rooms config directly,
allowing hub relays to forward without local clients.
2. Multi-hop forwarding: removed active_rooms filter — forward to
ALL connected peers except source. The receiving peer decides
whether to deliver or forward further.
3. Android relay_label: native RoomMember now includes relay_label
from RoomUpdate signal. Kotlin UI reads it for relay grouping.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Wire AdaptiveQualityController into Android engine for auto codec
switching based on network quality reports. Add color-coded TX/RX
codec badges to the in-call screen showing active codecs and Auto mode.
- Recv task: ingest QualityReports, feed to controller, signal profile
changes via AtomicU8 to send task
- Send task: check for pending profile switch at frame boundaries,
update encoder/FEC/frame size
- Track peer codec from incoming packet headers
- Kotlin UI: codec badges (blue=studio, green=good, amber=degraded,
red=catastrophic) with Auto tag
- Add .taskmaster to .gitignore
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Add RoomUpdate signal message to wzp-proto with participant count + list
- Add RoomParticipant struct (fingerprint + optional alias)
- Store fingerprint/alias in relay Participant struct
- Broadcast RoomUpdate to all room members on join and leave
- Add signal recv task in Android engine to handle RoomUpdate
- Surface room_participant_count + room_participants in CallStats JSON
- Show "X in room" with participant names in Android in-call UI
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- AudioPipeline: Kotlin AudioRecord/AudioTrack on JVM threads, PCM
shuttled to Rust via lock-free ring buffers + JNI
- FEC: RaptorQ fountain codes on encode (5 frames/block, 20% repair
ratio for GOOD profile), decoder feeds repair symbols for recovery
- Real audio level meter from mic RMS (replaces fake animation)
- Room name editable in UI (default: "android")
- Relay changed to pangolin.manko.yoga:4433
- Stats overlay shows FEC recovered count
- CallState now synced from polled stats (fixes "Connecting" stuck bug)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- New wzp-android crate with Oboe C++ backend, lock-free SPSC ring buffers,
engine orchestrator, codec pipeline, and Android Gradle project structure
- AEC (NLMS adaptive filter), AGC (two-stage with fast attack/slow release),
windowed-sinc FIR resampler replacing linear interpolation (wzp-codec)
- Opus encoder tuning: complexity 7 default, set_expected_loss support
- Mobile jitter buffer: asymmetric EMA (fast up/slow down), handoff spike
detection with 2s cooldown, configurable safety margin
- Network-aware quality control: cellular-specific thresholds, faster
downgrade on cellular, proactive tier drop on WiFi→cellular handoff,
FEC ratio boost during network transitions
- Handoff detection in PathMonitor via RTT jitter spike analysis
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
