Phase 3a of the DRED integration — the foundation for codec-layer loss
recovery. Adds three new safe wrappers to crates/wzp-codec/src/dred_ffi.rs
over the raw opusic-sys FFI, plus the reconstruction method on the existing
DecoderHandle. No call-site integration yet — that lands in Phase 3b (desktop)
and Phase 3c (Android).
New types:
- `DredDecoderHandle`: owns *mut OpusDREDDecoder from opus_dred_decoder_create.
Used for parsing DRED side-channel data out of arriving Opus packets.
This is a SEPARATE libopus object from OpusDecoder — it has its own
internal state. Freed via opus_dred_decoder_destroy on Drop.
- `DredState`: owns *mut OpusDRED from opus_dred_alloc (a fixed ~10.6 KB
buffer per libopus 1.5). Holds parsed DRED data between the parse and
reconstruct steps. Reusable — parse_into overwrites contents. Tracks
samples_available as a cached u32 so callers don't thread the value
separately. Freed via opus_dred_free on Drop.
New methods:
- `DredDecoderHandle::parse_into(&mut self, state: &mut DredState, packet)`
wraps opus_dred_parse with max_dred_samples=48000 (1s max), sampling_rate
=48000, defer_processing=0. Returns the positive sample offset of the
first decodable DRED sample, 0 if no DRED is present, or an error.
Populates state.samples_available so subsequent reconstruct calls know
the valid offset range.
- `DecoderHandle::reconstruct_from_dred(&mut self, state, offset_samples,
output)` wraps opus_decoder_dred_decode. Reconstructs audio at a specific
sample position (positive, measured backward from the DRED anchor packet)
into a caller-provided output buffer. Validates that 0 < offset_samples
<= state.samples_available() before calling the FFI to catch range bugs.
Tests (+7, wzp-codec total: 68 passing):
- dred_decoder_handle_creates_and_drops
- dred_state_creates_and_drops
- dred_state_reset_zeroes_counter
- dred_parse_and_reconstruct_roundtrip — end-to-end validation. Encodes
60 frames of a 300 Hz sine wave through a DRED-enabled Opus 24k encoder,
parses DRED state out of each arriving packet, asserts that at least one
packet carries non-zero samples_available (DRED warm-up completes within
the first second), then reconstructs 20 ms of audio from inside the
window and asserts non-zero total energy. This is the hard signal that
the full libopus 1.5 DRED FFI chain is correctly wired on our side.
- reconstruct_with_out_of_range_offset_errors — offset > samples_available
is rejected at the Rust layer before the FFI call.
- reconstruct_with_zero_offset_errors — offset <= 0 rejected.
- dred_parse_empty_packet_returns_zero — graceful handling of empty input.
Architectural note (divergence from PRD's literal wording):
The PRD said "jitter buffer takes a Box<dyn DredReconstructor>". After
checking Cargo.toml for wzp-transport, it does NOT depend on wzp-codec —
only wzp-proto. Adding a DRED state ring inside the jitter buffer would
require a new cross-crate dependency and couple the codec-agnostic jitter
buffer to libopus internals. Instead, Phase 3b will put the DRED state
ring and reconstruction dispatch in CallDecoder (one layer up from the
jitter buffer), intercepting the existing PlayoutResult::Missing signal
and attempting reconstruction before falling through to classical PLC.
The jitter buffer itself stays unchanged. Same lookahead/backfill
semantics, cleaner layering. PRD's intent preserved, implementation
refined.
Verification:
- cargo check --workspace: zero errors
- cargo test -p wzp-codec --lib: 68 passing (61 Phase 2 baseline + 7 new)
- The roundtrip test is the acceptance gate — it proves that
opus_dred_decoder_create, opus_dred_alloc, opus_dred_parse, and
opus_decoder_dred_decode all work correctly through our wrappers on
real libopus 1.5.2 output.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Phase 1 of the DRED integration (docs/PRD-dred-integration.md). The Opus
encoder now emits DRED (Deep REDundancy) bytes in every packet, carrying
a neural-coded history of recent audio that the decoder can use to
reconstruct loss bursts up to the configured window. Opus inband FEC
(LBRR) is disabled because DRED does the same job better and running both
wastes bitrate on overlapping protection.
Tiered DRED duration policy per PRD:
Studio (Opus 32k/48k/64k): 10 frames = 100 ms
Normal (Opus 16k/24k): 20 frames = 200 ms
Degraded (Opus 6k): 50 frames = 500 ms
Each profile switch (via adaptive quality) updates the DRED duration to
match the new tier. A 5% packet_loss floor is applied whenever DRED is
active, because libopus 1.5 gates DRED emission on non-zero packet_loss.
Real loss measurements from the quality adapter override upward.
Escape hatch: AUDIO_USE_LEGACY_FEC=1 reverts the encoder to Phase 0
behavior (inband FEC Mode1, DRED off, no loss floor). Read once at
OpusEncoder::new; call-scoped, not re-read mid-call. Trait-level
set_inband_fec becomes a no-op in DRED mode to preserve the invariant
even if external callers forget.
Observations from the bitrate probe test (dred_mode_roundtrip_voice_pattern):
DRED mode: 3649 bytes/sec (~29.2 kbps) on Opus 24k + 300 Hz sine
Legacy mode: 2383 bytes/sec (~19.1 kbps)
Delta: +10.1 kbps
The delta is considerably larger than the "+1 kbps flat" figure I carried
into the PRD from hazy memory of published DRED benchmarks. Likely because
the input (300 Hz sine) is very compressible so the base Opus rate in
legacy mode is well below the 24 kbps target, making the delta look
disproportionate. Signal-dependent — real speech would probably show a
different ratio. If production telemetry shows the overhead is excessive,
we can cut DRED duration on the normal tier from 200 ms to 100 ms as a
first tuning lever. Not blocking Phase 1 since the test still passes
within the reasonable 2000–8000 bytes/sec bounds.
Test changes (+8 tests, total wzp-codec: 61 passing):
- dred_duration_for_studio_tiers_is_100ms (per-profile policy)
- dred_duration_for_normal_tiers_is_200ms
- dred_duration_for_degraded_tier_is_500ms
- dred_duration_for_codec2_is_zero
- default_mode_is_dred_not_legacy (sanity check on fresh construction)
- dred_mode_roundtrip_voice_pattern (observes DRED bitrate, asserts bounds)
- profile_switch_refreshes_dred_duration (verifies set_profile updates DRED)
- set_inband_fec_noop_in_dred_mode (trait-level inband FEC no-op)
Verification:
- cargo check --workspace: zero errors, no new warnings
- cargo test -p wzp-codec: 61/61 passing (53 pre-Phase-1 baseline + 8 new)
- Empirical DRED bitrate observed via `rtk proxy cargo test
dred_mode_roundtrip_voice_pattern -- --nocapture`
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Phase 0 of the DRED integration (docs/PRD-dred-integration.md). No behavior
change: inband FEC stays ON, no DRED, same bitrate, same quality. This
commit unblocks Phase 1+ by getting us onto libopus 1.5.2 where DRED lives.
Rationale for going straight to a custom DecoderHandle: opusic-c::Decoder's
inner *mut OpusDecoder pointer is pub(crate), so we cannot reach it for the
Phase 3 DRED reconstruction path. Running two parallel decoders (one for
audio, one for DRED) would drift because the DRED decoder wouldn't see
normal decode calls. Single unified DecoderHandle over raw opusic-sys is
the only correct architecture, so we build it in Phase 0 rather than
rewriting opus_dec.rs twice.
Changes:
- Cargo.toml (workspace + wzp-codec): remove audiopus 0.3.0-rc.0, add
opusic-c 1.5.5 (bundled + dred features), opusic-sys 0.6.0 (bundled),
bytemuck 1. Pinned exactly for reproducible libopus 1.5.2.
- opus_enc.rs: rewritten against opusic_c::Encoder. Argument order for
Encoder::new swapped (Channels first). set_inband_fec(bool) now maps
to InbandFec::Mode1 (the libopus 1.5 equivalent of 1.3's LBRR). encode
uses bytemuck::cast_slice<i16,u16> at the &[u16] boundary.
- dred_ffi.rs (new): DecoderHandle wrapping *mut OpusDecoder directly via
opusic-sys. Owns the allocation, frees on Drop. Exposes decode,
decode_lost, and a pub(crate) as_raw_ptr() for the future Phase 3 DRED
reconstruction. Send+Sync justified via &mut self access discipline.
- opus_dec.rs: rewritten as a thin AudioDecoder impl over DecoderHandle.
Behavior identical to pre-swap.
Verification (Phase 0 acceptance gates):
- cargo check --workspace: clean (30 pre-existing warnings in jni_bridge.rs
unrelated to this work; zero in changed files).
- cargo test -p wzp-codec: 53 tests pass (50 pre-swap + 6 new: 3 in
dred_ffi.rs for DecoderHandle lifecycle, 3 in opus_enc.rs for version
check and roundtrip).
- linked_libopus_is_1_5 test asserts opusic_c::version() contains "1.5" —
hard signal that the swap landed correctly.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
1. Wire protocol: add Opus 32k/48k/64k (CodecId 6/7/8) + STUDIO
profiles with is_opus() helper. Opus enc/dec accept all Opus variants.
2. JNI bridge: expand profile_from_int to 7 levels (0-6) mapping to
GOOD, DEGRADED, CATASTROPHIC, Codec2_3200, STUDIO_32K/48K/64K.
3. Settings UI: replace radio buttons with Material3 Slider — 7 stops
from Studio 64k (green) to Codec2 1.2k (dark red), matching desktop.
4. Key-change warning: AlertDialog on connect when server fingerprint
has changed. Shows old vs new fingerprint, Accept New Key or Cancel.
Accepting saves the new fingerprint and proceeds with the call.
5. Engine recv: handle studio codec IDs in auto-switch path.
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>
T6 wiring: Trunking in relay hot path
- TrunkedForwarder wraps transport with TrunkBatcher
- run_participant uses 5ms flush timer when trunking enabled
- send_trunk/recv_trunk on QuinnTransport
- --trunking flag on relay config
- 2 new tests: forwarder batches, auto-flush on full
T7 wiring: Mini-frames in encoder/decoder
- MediaPacket::encode_compact/decode_compact with MiniFrameContext
- CallEncoder sends mini-headers for consecutive frames (full every 50th)
- CallDecoder auto-detects full vs mini on receive
- mini_frames_enabled in CallConfig (default true)
- 3 new tests: encode/decode sequence, periodic full, disabled mode
Noise suppression (nnnoiseless/RNNoise)
- NoiseSupressor in wzp-codec: pure Rust ML-based noise removal
- Processes 960-sample frames as two 480-sample halves
- Integrated in CallEncoder before silence detection
- noise_suppression in CallConfig (default true)
- 4 new tests: creation, processing, SNR improvement, passthrough
T1-S4: Adaptive playout delay
- AdaptivePlayoutDelay: EMA-based jitter tracking (NetEq-inspired)
- Computes target_delay from observed inter-arrival jitter
- JitterBuffer::new_adaptive() uses adaptive delay
- adaptive_jitter in CallConfig (default true)
- 5 new tests: stable, jitter increase, recovery, clamping, estimate
272 tests passing across all crates.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
