feat: direct playout mode, AEC far-end, audio processing switches

- Add --android/--direct-playout: bypass jitter buffer, decode on recv
  (matches Android engine architecture)
- Wire AEC far-end reference from decoded playout to encoder
- Add --no-aec, --no-agc, --no-fec, --no-silence, --no-denoise switches
- Fix BufferSize::Fixed(960) → Default for macOS CoreAudio compat
- Optimize wzp-codec, wzp-fec, audiopus, nnnoiseless in debug profile
- Add capture callback size diagnostic logging

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-client/src/cli.rs

@@ -14,7 +14,7 @@
 use std::net::SocketAddr;
 use std::sync::Arc;
 
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
 use wzp_client::call::{CallConfig, CallDecoder, CallEncoder};
 use wzp_proto::MediaTransport;
@@ -47,6 +47,12 @@ struct CliArgs {
     room: Option<String>,
     raw_room: bool,
     alias: Option<String>,
+    no_denoise: bool,
+    no_aec: bool,
+    no_agc: bool,
+    no_fec: bool,
+    no_silence: bool,
+    direct_playout: bool,
     token: Option<String>,
     _metrics_file: Option<String>,
 }
@@ -118,6 +124,12 @@ fn parse_args() -> CliArgs {
     let mut room = None;
     let mut raw_room = false;
     let mut alias = None;
+    let mut no_denoise = false;
+    let mut no_aec = false;
+    let mut no_agc = false;
+    let mut no_fec = false;
+    let mut no_silence = false;
+    let mut direct_playout = false;
     let mut token = None;
     let mut metrics_file = None;
     let mut relay_str = None;
@@ -163,6 +175,12 @@ fn parse_args() -> CliArgs {
                 room = Some(args.get(i).expect("--room requires a name").to_string());
             }
             "--raw-room" => raw_room = true,
+            "--no-denoise" => no_denoise = true,
+            "--no-aec" => no_aec = true,
+            "--no-agc" => no_agc = true,
+            "--no-fec" => no_fec = true,
+            "--no-silence" => no_silence = true,
+            "--direct-playout" | "--android" => direct_playout = true,
             "--alias" => {
                 i += 1;
                 alias = Some(args.get(i).expect("--alias requires a name").to_string());
@@ -222,6 +240,13 @@ fn parse_args() -> CliArgs {
                 eprintln!("  --room <name>          Room name (hashed for privacy before sending)");
                 eprintln!("  --raw-room             Send room name as-is (no hash, for Android compat)");
                 eprintln!("  --alias <name>         Display name shown to other participants");
+                eprintln!("  --no-denoise           Disable RNNoise noise suppression");
+                eprintln!("  --no-aec              Disable acoustic echo cancellation");
+                eprintln!("  --no-agc              Disable automatic gain control");
+                eprintln!("  --no-fec              Disable forward error correction");
+                eprintln!("  --no-silence          Disable silence suppression");
+                eprintln!("  --direct-playout      Bypass jitter buffer (decode on recv, like Android)");
+                eprintln!("  --android             Alias for --no-denoise --no-aec --no-silence --direct-playout");
                 eprintln!("  --token <token>        featherChat bearer token for relay auth");
                 eprintln!("  --metrics-file <path>  Write JSONL telemetry to file (1 line/sec)");
                 eprintln!("                         (48kHz mono s16le, play with ffplay -f s16le -ar 48000 -ch_layout mono file.raw)");
@@ -261,6 +286,12 @@ fn parse_args() -> CliArgs {
         room,
         raw_room,
         alias,
+        no_denoise,
+        no_aec,
+        no_agc,
+        no_fec,
+        no_silence,
+        direct_playout,
         token,
         _metrics_file: metrics_file,
     }
@@ -342,7 +373,15 @@ async fn main() -> anyhow::Result<()> {
     if cli.live {
         #[cfg(feature = "audio")]
         {
-            return run_live(transport).await;
+            let audio_opts = AudioOpts {
+                no_denoise: cli.no_denoise || cli.direct_playout,
+                no_aec: cli.no_aec,
+                no_agc: cli.no_agc,
+                no_fec: cli.no_fec,
+                no_silence: cli.no_silence || cli.direct_playout,
+                direct_playout: cli.direct_playout,
+            };
+            return run_live(transport, audio_opts).await;
         }
         #[cfg(not(feature = "audio"))]
         {
@@ -603,13 +642,24 @@ async fn run_file_mode(
 ///   QUIC → recv task → jitter buffer → decode tick (20ms) → AudioRing → CPAL playback callback
 ///
 /// All lock-free: CPAL callbacks use atomic ring buffers, no Mutex on the audio path.
+struct AudioOpts {
+    no_denoise: bool,
+    no_aec: bool,
+    no_agc: bool,
+    no_fec: bool,
+    no_silence: bool,
+    direct_playout: bool,
+}
+
 #[cfg(feature = "audio")]
 async fn run_live(
     transport: Arc<wzp_transport::QuinnTransport>,
+    opts: AudioOpts,
 ) -> anyhow::Result<()> {
     use std::sync::Arc as StdArc;
     use std::sync::atomic::{AtomicBool, Ordering};
     use wzp_client::audio_io::{AudioCapture, AudioPlayback};
+    use wzp_client::audio_ring::AudioRing;
     use wzp_client::call::JitterTelemetry;
 
     let capture = AudioCapture::start()?;
@@ -619,6 +669,10 @@ async fn run_live(
     let capture_ring = capture.ring().clone();
     let playout_ring = playback.ring().clone();
 
+    // Far-end reference ring: recv task writes decoded audio here,
+    // send task reads it to feed the AEC echo canceller.
+    let farend_ring = StdArc::new(AudioRing::new());
+
     let running = StdArc::new(AtomicBool::new(true));
 
     // --- Signal handler: set running=false on first Ctrl+C, force-quit on second ---
@@ -634,15 +688,40 @@ async fn run_live(
         std::process::exit(1);
     });
 
-    let config = CallConfig::default();
+    let config = CallConfig {
+        noise_suppression: !opts.no_denoise,
+        suppression_enabled: !opts.no_silence,
+        ..CallConfig::default()
+    };
+    {
+        let mut flags = Vec::new();
+        if opts.no_denoise { flags.push("denoise"); }
+        if opts.no_aec { flags.push("aec"); }
+        if opts.no_agc { flags.push("agc"); }
+        if opts.no_fec { flags.push("fec"); }
+        if opts.no_silence { flags.push("silence"); }
+        if opts.direct_playout { flags.push("jitter-buffer (direct playout)"); }
+        if !flags.is_empty() {
+            info!(disabled = %flags.join(", "), "audio processing overrides");
+        }
+    }
 
     // --- Send task: poll capture ring → encode → send via async ---
     let send_transport = transport.clone();
     let send_running = running.clone();
+    let no_aec = opts.no_aec;
+    let no_agc = opts.no_agc;
+    let _no_fec = opts.no_fec;
+    let send_farend = farend_ring.clone();
     let send_task = async move {
         let mut encoder = CallEncoder::new(&config);
+        if no_aec { encoder.set_aec_enabled(false); }
+        if no_agc { encoder.set_agc_enabled(false); }
         let mut capture_buf = vec![0i16; FRAME_SAMPLES];
+        let mut farend_buf = vec![0i16; FRAME_SAMPLES];
         let mut frames_sent: u64 = 0;
+        let mut polls: u64 = 0;
+        let mut last_diag = std::time::Instant::now();
 
         loop {
             if !send_running.load(Ordering::Relaxed) {
@@ -652,6 +731,12 @@ async fn run_live(
             let avail = capture_ring.available();
             if avail < FRAME_SAMPLES {
                 tokio::time::sleep(std::time::Duration::from_millis(5)).await;
+                polls += 1;
+                // Diagnostic every 2 seconds
+                if last_diag.elapsed().as_secs() >= 2 {
+                    info!(avail, polls, frames_sent, "send: ring starved (avail < {FRAME_SAMPLES})");
+                    last_diag = std::time::Instant::now();
+                }
                 continue;
             }
 
@@ -660,6 +745,16 @@ async fn run_live(
                 continue;
             }
 
+            // Feed AEC far-end reference: what was played through the speaker.
+            // Must be called BEFORE encode_frame processes the mic signal.
+            if !no_aec {
+                while send_farend.available() >= FRAME_SAMPLES {
+                    send_farend.read(&mut farend_buf);
+                    encoder.feed_aec_farend(&farend_buf);
+                }
+            }
+
+            let t0 = std::time::Instant::now();
             let packets = match encoder.encode_frame(&capture_buf) {
                 Ok(p) => p,
                 Err(e) => {
@@ -667,6 +762,7 @@ async fn run_live(
                     continue;
                 }
             };
+            let encode_us = t0.elapsed().as_micros();
 
             for pkt in &packets {
                 if let Err(e) = send_transport.send_media(pkt).await {
@@ -676,58 +772,121 @@ async fn run_live(
             }
 
             frames_sent += 1;
-            if frames_sent == 1 || frames_sent % 500 == 0 {
-                info!(frames_sent, "send progress");
+            if frames_sent <= 5 || frames_sent % 500 == 0 {
+                info!(frames_sent, encode_us, pkts = packets.len(), "send progress");
             }
         }
     };
 
-    // --- Recv task: receive packets → ingest into jitter buffer ---
-    // Uses timeout so it can check the running flag and exit on Ctrl+C.
+    // --- Recv + playout ---
     let recv_transport = transport.clone();
     let recv_running = running.clone();
-    let config = CallConfig::default();
-    let decoder = StdArc::new(tokio::sync::Mutex::new(CallDecoder::new(&config)));
-    let decoder_recv = decoder.clone();
+    let direct_playout = opts.direct_playout;
 
-    let recv_task = async move {
-        let mut packets_received: u64 = 0;
-        loop {
-            if !recv_running.load(Ordering::Relaxed) {
-                break;
-            }
-            // Timeout so we can check running flag periodically
-            let result = tokio::time::timeout(
-                std::time::Duration::from_millis(100),
-                recv_transport.recv_media(),
-            )
-            .await;
-            match result {
-                Ok(Ok(Some(pkt))) => {
-                    let mut dec = decoder_recv.lock().await;
-                    dec.ingest(pkt);
-                    packets_received += 1;
-                    if packets_received == 1 || packets_received % 500 == 0 {
-                        info!(packets_received, depth = dec.stats().current_depth, "recv progress");
+    // Direct playout: decode on recv, write straight to playout ring (like Android).
+    // Jitter buffer mode: ingest into jitter buffer, decode on 20ms tick.
+    let recv_task = {
+        let playout_ring = playout_ring.clone();
+        let farend_ring = farend_ring.clone();
+        let config = CallConfig::default();
+        let decoder = StdArc::new(tokio::sync::Mutex::new(CallDecoder::new(&config)));
+        let decoder_recv = decoder.clone();
+
+        async move {
+            let mut packets_received: u64 = 0;
+            let mut timeouts: u64 = 0;
+            // For direct playout: raw Opus decoder + AGC
+            let mut opus_dec = if direct_playout {
+                Some(wzp_codec::create_decoder(wzp_proto::QualityProfile::GOOD))
+            } else {
+                None
+            };
+            let mut playout_agc = wzp_codec::AutoGainControl::new();
+            let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
+
+            loop {
+                if !recv_running.load(Ordering::Relaxed) {
+                    break;
+                }
+                let result = tokio::time::timeout(
+                    std::time::Duration::from_millis(100),
+                    recv_transport.recv_media(),
+                )
+                .await;
+                match result {
+                    Ok(Ok(Some(pkt))) => {
+                        packets_received += 1;
+
+                        if direct_playout {
+                            // Android path: decode immediately, AGC, write to ring
+                            if !pkt.header.is_repair {
+                                if let Some(ref mut dec) = opus_dec {
+                                    match dec.decode(&pkt.payload, &mut pcm_buf) {
+                                        Ok(n) => {
+                                            if !no_agc {
+                                                playout_agc.process_frame(&mut pcm_buf[..n]);
+                                            }
+                                            playout_ring.write(&pcm_buf[..n]);
+                                            // Feed far-end ring for AEC
+                                            farend_ring.write(&pcm_buf[..n]);
+                                        }
+                                        Err(e) => {
+                                            if let Ok(n) = dec.decode_lost(&mut pcm_buf) {
+                                                playout_ring.write(&pcm_buf[..n]);
+                                            }
+                                            if packets_received < 10 {
+                                                warn!("decode error: {e}");
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        } else {
+                            // Jitter buffer path
+                            let mut dec = decoder_recv.lock().await;
+                            dec.ingest(pkt);
+                        }
+
+                        if packets_received == 1 || packets_received % 500 == 0 {
+                            info!(packets_received, direct_playout, "recv progress");
+                        }
+                        timeouts = 0;
+                    }
+                    Ok(Ok(None)) => {
+                        info!("connection closed");
+                        break;
+                    }
+                    Ok(Err(e)) => {
+                        error!("recv error: {e}");
+                        break;
+                    }
+                    Err(_) => {
+                        timeouts += 1;
+                        if timeouts == 50 {
+                            info!("recv: no media packets received in 5s");
+                        }
                     }
                 }
-                Ok(Ok(None)) => {
-                    info!("connection closed");
-                    break;
-                }
-                Ok(Err(e)) => {
-                    error!("recv error: {e}");
-                    break;
-                }
-                Err(_) => {} // timeout — loop and check running flag
             }
         }
     };
 
-    // --- Playout tick: decode from jitter buffer at steady 20ms intervals ---
+    // Playout tick — only used when NOT in direct playout mode
     let playout_running = running.clone();
-    let decoder_playout = decoder.clone();
     let playout_task = async move {
+        if direct_playout {
+            // Direct playout handles everything in recv_task — just park here
+            loop {
+                tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+                if !playout_running.load(Ordering::Relaxed) {
+                    break;
+                }
+            }
+            return;
+        }
+
+        let config = CallConfig::default();
+        let mut decoder = CallDecoder::new(&config);
         let mut pcm_buf = vec![0i16; FRAME_SAMPLES];
         let mut interval = tokio::time::interval(std::time::Duration::from_millis(20));
         interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
@@ -738,19 +897,16 @@ async fn run_live(
                 break;
             }
 
-            let mut dec = decoder_playout.lock().await;
-
-            // Drain ready frames from jitter buffer into playout ring.
             let mut decoded_this_tick = 0;
-            while let Some(n) = dec.decode_next(&mut pcm_buf) {
+            while let Some(n) = decoder.decode_next(&mut pcm_buf) {
                 playout_ring.write(&pcm_buf[..n]);
                 decoded_this_tick += 1;
                 if decoded_this_tick >= 2 {
-                    break; // Don't drain too aggressively in one tick
+                    break;
                 }
             }
 
-            telemetry.maybe_log(dec.stats());
+            telemetry.maybe_log(decoder.stats());
         }
     };