feat(dred): continuous DRED tuning, PMTUD, extended Opus6k window
- DredTuner: maps live network metrics (loss/RTT/jitter) to continuous DRED duration every ~500ms instead of discrete tier-locked values. Includes jitter-spike detection for pre-emptive Starlink-style boost. - Opus6k DRED extended from 500ms to 1040ms (max libopus 1.5 supports) - PMTUD: quinn MtuDiscoveryConfig with upper_bound=1452, 300s interval - TrunkedForwarder respects discovered MTU (was hard-coded 1200) - QuinnPathSnapshot exposes quinn internal stats + discovered MTU - AudioEncoder trait: set_expected_loss() + set_dred_duration() methods - PathMonitor: sliding-window jitter variance for spike detection - Integrated into both Android and desktop send tasks in engine.rs - 14 new tests (10 tuner unit + 4 encoder integration) - Updated ARCHITECTURE.md, PROGRESS.md, PRD-dred-integration, PRD-mtu Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
Siavash Sameni
@@ -103,11 +103,13 @@ sequenceDiagram
|
||||
participant RNN as RNNoise<br/>(2 x 480)
|
||||
participant VAD as SilenceDetector
|
||||
participant Codec as Opus / Codec2
|
||||
participant DT as DredTuner<br/>(wzp-proto)
|
||||
participant FEC as RaptorQ FEC
|
||||
participant INT as Interleaver<br/>(depth=3)
|
||||
participant HDR as MediaHeader<br/>(12B or Mini 4B)
|
||||
participant Enc as ChaCha20-Poly1305
|
||||
participant QUIC as QUIC Datagram
|
||||
participant QPS as QuinnPathSnapshot
|
||||
|
||||
Mic->>Ring: f32 x 512 (macOS callback)
|
||||
Ring->>Ring: Accumulate to 960 samples
|
||||
@@ -118,10 +120,19 @@ sequenceDiagram
|
||||
else Silence (>100ms)
|
||||
VAD->>Codec: ComfortNoise (every 200ms)
|
||||
end
|
||||
Codec->>FEC: Compressed bytes (pad to 256B symbol)
|
||||
FEC->>FEC: Accumulate block (5-10 symbols)
|
||||
FEC->>INT: Source + repair symbols
|
||||
INT->>HDR: Interleaved packets
|
||||
|
||||
Note over QPS,DT: Every 25 frames (~500ms)
|
||||
QPS->>DT: loss_pct, rtt_ms, jitter_ms
|
||||
DT->>Codec: set_dred_duration() + set_expected_loss()
|
||||
|
||||
alt Opus tier (any bitrate)
|
||||
Codec->>HDR: Compressed bytes + DRED side-channel (no RaptorQ)
|
||||
else Codec2 tier
|
||||
Codec->>FEC: Compressed bytes (pad to 256B symbol)
|
||||
FEC->>FEC: Accumulate block (5-10 symbols)
|
||||
FEC->>INT: Source + repair symbols
|
||||
INT->>HDR: Interleaved packets
|
||||
end
|
||||
HDR->>Enc: Header as AAD
|
||||
Enc->>QUIC: Encrypted payload + 16B tag
|
||||
```
|
||||
@@ -134,6 +145,9 @@ sequenceDiagram
|
||||
- Silence detection uses VAD + 100ms hangover before switching to ComfortNoise
|
||||
- FEC symbols are padded to **256 bytes** with a 2-byte LE length prefix
|
||||
- MiniHeaders (4 bytes) replace full headers (12 bytes) for 49 of every 50 frames
|
||||
- DRED tuner polls quinn path stats every 25 frames (~500ms) and adjusts DRED lookback duration continuously
|
||||
- Opus tiers bypass RaptorQ entirely -- DRED handles loss recovery at the codec layer
|
||||
- Opus6k DRED window: 1040ms (maximum libopus allows)
|
||||
|
||||
## Audio Decode Pipeline
|
||||
|
||||
@@ -154,13 +168,30 @@ sequenceDiagram
|
||||
Dec->>AR: Decrypt (header = AAD)
|
||||
AR->>AR: Check seq window (reject replay)
|
||||
AR->>HDR: Verified packet
|
||||
HDR->>DEINT: MediaHeader + payload
|
||||
DEINT->>FEC: Reordered symbols by block
|
||||
FEC->>FEC: Attempt decode (need K of K+R)
|
||||
FEC->>JIT: Recovered audio frames
|
||||
|
||||
alt Opus packet
|
||||
HDR->>JIT: Direct to jitter buffer (no FEC/interleave)
|
||||
else Codec2 packet
|
||||
HDR->>DEINT: MediaHeader + payload
|
||||
DEINT->>FEC: Reordered symbols by block
|
||||
FEC->>FEC: Attempt decode (need K of K+R)
|
||||
FEC->>JIT: Recovered audio frames
|
||||
end
|
||||
|
||||
JIT->>JIT: BTreeMap ordered by seq
|
||||
JIT->>JIT: Wait until depth >= target
|
||||
JIT->>Codec: Pop lowest seq frame
|
||||
|
||||
alt Packet present
|
||||
JIT->>Codec: Pop lowest seq frame
|
||||
else Packet missing (Opus)
|
||||
JIT->>Codec: DRED reconstruction (neural)
|
||||
alt DRED fails or unavailable
|
||||
Codec->>Codec: Classical PLC fallback
|
||||
end
|
||||
else Packet missing (Codec2)
|
||||
Codec->>Codec: Classical PLC
|
||||
end
|
||||
|
||||
Codec->>Ring: PCM i16 x 960
|
||||
Ring->>SPK: Audio callback pulls samples
|
||||
```
|
||||
@@ -172,6 +203,8 @@ sequenceDiagram
|
||||
- Jitter buffer target: **10 packets (200ms)** for client, **50 packets (1s)** for relay
|
||||
- Desktop client uses **direct playout** (no jitter buffer) with lock-free ring
|
||||
- Codec2 frames at 8 kHz are resampled to 48 kHz transparently
|
||||
- DRED reconstruction: on packet loss, decoder tries neural DRED reconstruction before falling back to classical PLC
|
||||
- Jitter-spike detection pre-emptively boosts DRED to ceiling when jitter variance spikes >30%
|
||||
|
||||
## Relay SFU Forwarding
|
||||
|
||||
@@ -348,7 +381,7 @@ Used for 49 of every 50 frames (~1s cycle). Saves 8 bytes per packet (67% header
|
||||
[session_id: 2][len: u16][payload: len] x count
|
||||
```
|
||||
|
||||
Packs multiple session packets into one QUIC datagram. Maximum 10 entries or 1200 bytes, flushed every 5ms.
|
||||
Packs multiple session packets into one QUIC datagram. Maximum 10 entries or PMTUD-discovered MTU (starts at 1200, grows to ~1452 on Ethernet), flushed every 5ms.
|
||||
|
||||
### QualityReport (4 bytes, optional trailer)
|
||||
|
||||
@@ -361,6 +394,40 @@ Byte 3: bitrate_cap_kbps (0-255 kbps)
|
||||
|
||||
Appended to a media packet when the Q flag is set in the MediaHeader.
|
||||
|
||||
## Path MTU Discovery
|
||||
|
||||
Quinn's PLPMTUD is enabled with:
|
||||
- `initial_mtu`: 1200 bytes (QUIC minimum, always safe)
|
||||
- `upper_bound`: 1452 bytes (Ethernet minus IP/UDP/QUIC headers)
|
||||
- `interval`: 300s (re-probe every 5 minutes)
|
||||
- `black_hole_cooldown`: 30s (faster retry on lossy links)
|
||||
|
||||
The discovered MTU is exposed via `QuinnPathSnapshot::current_mtu` and used by:
|
||||
- `TrunkedForwarder`: refreshes `max_bytes` on every send to fill larger datagrams
|
||||
- Future video framer: larger MTU = fewer application-layer fragments per frame
|
||||
|
||||
## Continuous DRED Tuning
|
||||
|
||||
Instead of locking DRED duration to 3 discrete quality tiers, the `DredTuner` (in `wzp-proto::dred_tuner`) maps live path quality to a continuous DRED duration:
|
||||
|
||||
| Input | Source | Update Rate |
|
||||
|-------|--------|-------------|
|
||||
| Loss % | `QuinnPathSnapshot::loss_pct` (from quinn ACK frames) | Every 25 packets (~500ms) |
|
||||
| RTT ms | `QuinnPathSnapshot::rtt_ms` (quinn congestion controller) | Every 25 packets |
|
||||
| Jitter ms | `PathMonitor::jitter_ms` (EWMA of RTT variance) | Every 25 packets |
|
||||
|
||||
### Mapping Logic
|
||||
|
||||
- **Baseline**: codec-tier default (Studio=100ms, Good=200ms, Degraded=500ms)
|
||||
- **Ceiling**: codec-tier max (Studio=300ms, Good=500ms, Degraded=1040ms)
|
||||
- **Continuous**: linear interpolation between baseline and ceiling based on loss (0%->baseline, 40%->ceiling)
|
||||
- **RTT phantom loss**: high RTT (>200ms) adds phantom loss contribution to keep DRED generous
|
||||
- **Jitter spike**: >30% EWMA spike pre-emptively boosts to ceiling for ~5s cooldown
|
||||
|
||||
### Output
|
||||
|
||||
`DredTuning { dred_frames: u8, expected_loss_pct: u8 }` -> fed to `CallEncoder::apply_dred_tuning()` -> `OpusEncoder::set_dred_duration()` + `set_expected_loss()`
|
||||
|
||||
## Signal Message Handshake Flow
|
||||
|
||||
```mermaid
|
||||
|
||||
Reference in New Issue
Block a user