完善音频采集

src/audio/capture.rs

@@ -97,12 +97,14 @@ pub struct AudioFrame {
 }
 
 impl AudioFrame {
-    pub fn new(data: Bytes, config: &AudioConfig, sequence: u64) -> Self {
+    /// One capture block: `sample_rate` must be the **hardware** rate (e.g. ALSA `actual_rate`).
+    pub fn new_interleaved(data: Bytes, channels: u32, sample_rate: u32, sequence: u64) -> Self {
+        let bps = 2 * channels;
         Self {
-            samples: data.len() as u32 / config.bytes_per_sample(),
+            samples: data.len() as u32 / bps,
             data,
-            sample_rate: config.sample_rate,
-            channels: config.channels,
+            sample_rate,
+            channels,
             sequence,
             timestamp: Instant::now(),
         }
@@ -285,10 +287,17 @@ fn run_capture(
         .map(|h| h.get_rate().unwrap_or(config.sample_rate))
         .unwrap_or(config.sample_rate);
 
-    info!(
-        "Audio capture configured: {}Hz {}ch (requested {}Hz)",
-        actual_rate, config.channels, config.sample_rate
-    );
+    if actual_rate != config.sample_rate {
+        info!(
+            "ALSA sample rate differs from requested ({}Hz vs {}Hz); streamer will resample to 48000Hz for Opus",
+            actual_rate, config.sample_rate
+        );
+    } else {
+        info!(
+            "Audio capture configured: {}Hz {}ch (requested {}Hz)",
+            actual_rate, config.channels, config.sample_rate
+        );
+    }
 
     // Prepare for capture
     pcm.prepare()
@@ -296,9 +305,17 @@ fn run_capture(
 
     let _ = state.send(CaptureState::Running);
 
-    // Allocate buffer - use u8 directly for zero-copy
-    let frame_bytes = config.bytes_per_frame();
-    let mut buffer = vec![0u8; frame_bytes];
+    // Sized from actual period — `readi` may return up to ~one period of frames per call.
+    let period_frames = pcm
+        .hw_params_current()
+        .ok()
+        .and_then(|h| h.get_period_size().ok())
+        .map(|f| f as usize)
+        .unwrap_or(1024)
+        .max(256);
+    let buf_frames = period_frames.saturating_mul(4).max(2048);
+    let bytes_per_frame = (config.channels as usize) * 2;
+    let mut buffer = vec![0u8; buf_frames * bytes_per_frame];
 
     // Capture loop
     while !stop_flag.load(Ordering::Relaxed) {
@@ -337,8 +354,12 @@ fn run_capture(
 
                 // Directly use the buffer slice (already in correct byte format)
                 let seq = sequence.fetch_add(1, Ordering::Relaxed);
-                let frame =
-                    AudioFrame::new(Bytes::copy_from_slice(&buffer[..byte_count]), config, seq);
+                let frame = AudioFrame::new_interleaved(
+                    Bytes::copy_from_slice(&buffer[..byte_count]),
+                    config.channels,
+                    actual_rate,
+                    seq,
+                );
 
                 // Send to subscribers
                 if frame_tx.receiver_count() > 0 {

src/audio/controller.rs

@@ -381,7 +381,7 @@ impl AudioController {
     pub async fn update_config(&self, new_config: AudioControllerConfig) -> Result<()> {
         let was_streaming = self.is_streaming().await;
 
-        // Stop streaming if running
+        // Stop streaming if running (device/quality/enabled may all change)
         if was_streaming {
             self.stop_streaming().await?;
         }
@@ -389,8 +389,10 @@ impl AudioController {
         // Update config
         *self.config.write().await = new_config.clone();
 
-        // Restart streaming if it was running and still enabled
-        if was_streaming && new_config.enabled {
+        // Start whenever audio is enabled — not only when we were already streaming.
+        // Otherwise PATCH /config/audio alone leaves enabled=true with no capture until
+        // POST /audio/start, which races WebRTC reconnect and matches "apply twice" reports.
+        if new_config.enabled {
             self.start_streaming().await?;
         }
 

src/audio/mod.rs

@@ -13,6 +13,7 @@ pub mod controller;
 pub mod device;
 pub mod encoder;
 pub mod monitor;
+pub mod resample;
 pub mod streamer;
 
 pub use capture::{AudioCapturer, AudioConfig, AudioFrame};

src/audio/resample.rs

@@ -0,0 +1,202 @@
+//! Resample capture PCM to 48 kHz stereo for Opus (fixed 20 ms / 960×2 samples).
+
+const OUT_RATE: f64 = 48000.0;
+const OPUS_STEREO_SAMPLES: usize = 960 * 2;
+
+enum PipelineState {
+    /// Native 48 kHz interleaved stereo: only buffer and slice into 20 ms blocks (no float work).
+    Stereo48kPassthrough,
+    /// Other rates / mono: linear interpolation to 48 kHz stereo.
+    Resample {
+        in_rate: u32,
+        in_channels: u32,
+        next_out_frame: u64,
+        buffer_start_frame: u64,
+    },
+}
+
+/// Converts incoming interleaved PCM to 48 kHz stereo, then exposes fixed 960×2-sample chunks.
+pub struct Opus48kPcmBuffer {
+    state: PipelineState,
+    pending: Vec<i16>,
+}
+
+impl Opus48kPcmBuffer {
+    pub fn new(in_rate: u32, in_channels: u32) -> Self {
+        let ch = in_channels.max(1);
+        let rate = in_rate.max(1);
+        let state = if rate == 48000 && ch == 2 {
+            PipelineState::Stereo48kPassthrough
+        } else {
+            PipelineState::Resample {
+                in_rate: rate,
+                in_channels: ch,
+                next_out_frame: 0,
+                buffer_start_frame: 0,
+            }
+        };
+        Self {
+            state,
+            pending: Vec::new(),
+        }
+    }
+
+    /// True when input is already 48 kHz stereo (no interpolation loop).
+    #[cfg(test)]
+    pub fn is_passthrough(&self) -> bool {
+        matches!(self.state, PipelineState::Stereo48kPassthrough)
+    }
+
+    /// Append one capture block (`sample_rate` must match the rate this buffer was built for).
+    pub fn push_interleaved(&mut self, data: &[i16]) {
+        self.pending.extend_from_slice(data);
+    }
+
+    /// Drain as many 960×2 stereo S16LE samples (20 ms @ 48 kHz) as possible.
+    pub fn pop_opus_frames(&mut self, out: &mut Vec<i16>) {
+        match &mut self.state {
+            PipelineState::Stereo48kPassthrough => {
+                while self.pending.len() >= OPUS_STEREO_SAMPLES {
+                    out.extend_from_slice(&self.pending[..OPUS_STEREO_SAMPLES]);
+                    self.pending.drain(..OPUS_STEREO_SAMPLES);
+                }
+            }
+            PipelineState::Resample {
+                in_rate,
+                in_channels,
+                next_out_frame,
+                buffer_start_frame,
+            } => {
+                let ch = *in_channels as usize;
+                if ch == 0 {
+                    return;
+                }
+
+                loop {
+                    let batch_start = *next_out_frame;
+                    let mut block = Vec::with_capacity(OPUS_STEREO_SAMPLES);
+                    let mut complete = true;
+
+                    for i in 0u64..960 {
+                        let k = batch_start + i;
+                        let p_abs = (k as f64) * (*in_rate as f64) / OUT_RATE;
+                        let f_abs = p_abs.floor() as u64;
+                        let frac = p_abs - f_abs as f64;
+
+                        let f_rel = f_abs.saturating_sub(*buffer_start_frame) as usize;
+                        if f_rel + 1 >= self.pending.len() / ch {
+                            complete = false;
+                            break;
+                        }
+
+                        let base0 = f_rel * ch;
+                        let base1 = (f_rel + 1) * ch;
+
+                        let (l, r) = if *in_channels >= 2 {
+                            let l0 = self.pending[base0] as f64;
+                            let l1 = self.pending[base1] as f64;
+                            let r0 = self.pending[base0 + 1] as f64;
+                            let r1 = self.pending[base1 + 1] as f64;
+                            (l0 + frac * (l1 - l0), r0 + frac * (r1 - r0))
+                        } else {
+                            let m0 = self.pending[base0] as f64;
+                            let m1 = self.pending[base1] as f64;
+                            let v = m0 + frac * (m1 - m0);
+                            (v, v)
+                        };
+
+                        block.push(clamp_f64_to_i16(l));
+                        block.push(clamp_f64_to_i16(r));
+                    }
+
+                    if !complete || block.len() != OPUS_STEREO_SAMPLES {
+                        break;
+                    }
+
+                    out.extend_from_slice(&block);
+                    *next_out_frame = batch_start + 960;
+                    trim_resample_prefix(
+                        &mut self.pending,
+                        *in_rate,
+                        *next_out_frame,
+                        buffer_start_frame,
+                        ch,
+                    );
+                }
+            }
+        }
+    }
+}
+
+fn trim_resample_prefix(
+    pending: &mut Vec<i16>,
+    in_rate: u32,
+    next_out_frame: u64,
+    buffer_start_frame: &mut u64,
+    ch: usize,
+) {
+    if pending.is_empty() {
+        return;
+    }
+
+    let p_next = (next_out_frame as f64) * (in_rate as f64) / OUT_RATE;
+    let need_abs = p_next.floor() as u64;
+    let keep_from_abs = need_abs.saturating_sub(1);
+    if keep_from_abs <= *buffer_start_frame {
+        return;
+    }
+
+    let drop_frames = (keep_from_abs - *buffer_start_frame) as usize;
+    let drop_samples = drop_frames.saturating_mul(ch).min(pending.len());
+    if drop_samples > 0 {
+        pending.drain(0..drop_samples);
+        *buffer_start_frame += drop_frames as u64;
+    }
+}
+
+#[inline]
+fn clamp_f64_to_i16(v: f64) -> i16 {
+    v.round().clamp(i16::MIN as f64, i16::MAX as f64) as i16
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn passthrough_48k_identity_tone_length() {
+        let mut buf = Opus48kPcmBuffer::new(48000, 2);
+        assert!(buf.is_passthrough());
+        let mut chunk = vec![0i16; 960 * 2];
+        for i in 0..960 {
+            let s = (i as f32 * 0.1).sin() * 3000.0;
+            chunk[2 * i] = s as i16;
+            chunk[2 * i + 1] = s as i16;
+        }
+        buf.push_interleaved(&chunk);
+        let mut out = Vec::new();
+        buf.pop_opus_frames(&mut out);
+        assert_eq!(out.len(), 960 * 2);
+    }
+
+    #[test]
+    fn upsample_44k_to_48k_chunk() {
+        let mut buf = Opus48kPcmBuffer::new(44100, 2);
+        assert!(!buf.is_passthrough());
+        let mut chunk = vec![0i16; 882 * 2];
+        for i in 0..882 {
+            chunk[2 * i] = (i as i16).wrapping_mul(10);
+            chunk[2 * i + 1] = (i as i16).wrapping_mul(-7);
+        }
+        buf.push_interleaved(&chunk);
+        let mut out = Vec::new();
+        buf.pop_opus_frames(&mut out);
+        assert_eq!(out.len(), 960 * 2, "expected one 20ms Opus block");
+    }
+
+    #[test]
+    fn mono_48k_not_passthrough() {
+        let buf = Opus48kPcmBuffer::new(48000, 1);
+        assert!(!buf.is_passthrough());
+    }
+}

src/audio/streamer.rs

@@ -9,9 +9,12 @@ use std::time::Instant;
 use tokio::sync::{broadcast, watch, Mutex, RwLock};
 use tracing::{error, info, warn};
 
-use super::capture::{AudioCapturer, AudioConfig, CaptureState};
+use super::capture::{AudioCapturer, AudioConfig, AudioFrame, CaptureState};
 use super::encoder::{OpusConfig, OpusEncoder, OpusFrame};
+use super::resample::Opus48kPcmBuffer;
 use crate::error::{AppError, Result};
+use bytemuck;
+use bytes::Bytes;
 
 /// Audio stream state
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
@@ -254,6 +257,9 @@ impl AudioStreamer {
 
         info!("Audio stream task started");
 
+        let mut to_48k: Option<Opus48kPcmBuffer> = None;
+        let mut queued_48k: Vec<i16> = Vec::new();
+
         loop {
             // Check stop flag (atomic, no async lock needed)
             if stop_flag.load(Ordering::Relaxed) {
@@ -273,27 +279,56 @@ impl AudioStreamer {
 
             match recv_result {
                 Ok(Ok(audio_frame)) => {
-                    // Encode to Opus
-                    let opus_result = {
-                        let mut enc_guard = encoder.lock().await;
-                        (*enc_guard)
-                            .as_mut()
-                            .map(|enc| enc.encode_frame(&audio_frame))
+                    if to_48k.is_none() {
+                        to_48k = Some(Opus48kPcmBuffer::new(
+                            audio_frame.sample_rate,
+                            audio_frame.channels,
+                        ));
+                    }
+                    let pipeline = match to_48k.as_mut() {
+                        Some(p) => p,
+                        None => continue,
                     };
 
-                    match opus_result {
-                        Some(Ok(opus_frame)) => {
-                            // Publish latest frame to subscribers
-                            if opus_tx.receiver_count() > 0 {
-                                let _ = opus_tx.send(Some(Arc::new(opus_frame)));
+                    let samples: &[i16] = match bytemuck::try_cast_slice(&audio_frame.data) {
+                        Ok(s) => s,
+                        Err(_) => {
+                            warn!("Audio frame size not multiple of 2; skipping");
+                            continue;
+                        }
+                    };
+                    if !samples.is_empty() {
+                        pipeline.push_interleaved(samples);
+                    }
+                    pipeline.pop_opus_frames(&mut queued_48k);
+
+                    while queued_48k.len() >= 960 * 2 {
+                        let pcm_20ms =
+                            Bytes::copy_from_slice(bytemuck::cast_slice(&queued_48k[..960 * 2]));
+                        queued_48k.drain(..960 * 2);
+
+                        let frame_48k = AudioFrame::new_interleaved(pcm_20ms, 2, 48000, 0);
+
+                        let opus_result = {
+                            let mut enc_guard = encoder.lock().await;
+                            (*enc_guard)
+                                .as_mut()
+                                .map(|enc| enc.encode_frame(&frame_48k))
+                        };
+
+                        match opus_result {
+                            Some(Ok(opus_frame)) => {
+                                if opus_tx.receiver_count() > 0 {
+                                    let _ = opus_tx.send(Some(Arc::new(opus_frame)));
+                                }
+                            }
+                            Some(Err(e)) => {
+                                error!("Opus encode error: {}", e);
+                            }
+                            None => {
+                                warn!("Encoder not available");
+                                break;
                             }
-                        }
-                        Some(Err(e)) => {
-                            error!("Opus encode error: {}", e);
-                        }
-                        None => {
-                            warn!("Encoder not available");
-                            break;
                         }
                     }
                 }