feat(core): vad-driven listening window state machine

crates/jarvis-core/src/audio_processing/vad.rs

@@ -1,5 +1,8 @@
 mod none;
 mod energy;
+pub mod listen_window;
+#[cfg(feature = "webrtc-vad")]
+pub mod webrtc;
 
 use once_cell::sync::OnceCell;
 use parking_lot::Mutex;

crates/jarvis-core/src/audio_processing/vad/listen_window.rs

@@ -0,0 +1,79 @@
+use crate::config;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum WindowDecision {
+    KeepListening,
+    Close,
+    HardCap,
+}
+
+#[derive(Debug, Clone)]
+pub struct ListenWindow {
+    frame_ms: u32,
+    elapsed_ms: u32,
+    speech_ms: u32,
+    silence_ms: u32,
+    end_silence_ms: u32,
+    min_speech_ms: u32,
+    min_listen_ms: u32,
+    max_listen_ms: u32,
+}
+
+impl ListenWindow {
+    pub fn new(frame_ms: u32) -> Self {
+        Self::with_params(
+            frame_ms,
+            config::VAD_COMMAND_END_SILENCE_MS,
+            config::VAD_COMMAND_MIN_SPEECH_MS,
+            config::VAD_COMMAND_MIN_LISTEN_MS,
+            config::VAD_COMMAND_MAX_LISTEN_MS,
+        )
+    }
+
+    pub fn with_params(
+        frame_ms: u32,
+        end_silence_ms: u32,
+        min_speech_ms: u32,
+        min_listen_ms: u32,
+        max_listen_ms: u32,
+    ) -> Self {
+        Self {
+            frame_ms,
+            elapsed_ms: 0,
+            speech_ms: 0,
+            silence_ms: 0,
+            end_silence_ms,
+            min_speech_ms,
+            min_listen_ms,
+            max_listen_ms,
+        }
+    }
+
+    pub fn push(&mut self, is_speech: bool) -> WindowDecision {
+        self.elapsed_ms = self.elapsed_ms.saturating_add(self.frame_ms);
+
+        if is_speech {
+            self.speech_ms = self.speech_ms.saturating_add(self.frame_ms);
+            self.silence_ms = 0;
+        } else {
+            self.silence_ms = self.silence_ms.saturating_add(self.frame_ms);
+        }
+
+        if self.elapsed_ms >= self.max_listen_ms {
+            return WindowDecision::HardCap;
+        }
+        if self.elapsed_ms < self.min_listen_ms {
+            return WindowDecision::KeepListening;
+        }
+        if self.speech_ms >= self.min_speech_ms && self.silence_ms >= self.end_silence_ms {
+            return WindowDecision::Close;
+        }
+        WindowDecision::KeepListening
+    }
+
+    pub fn elapsed_ms(&self) -> u32 { self.elapsed_ms }
+    pub fn speech_ms(&self) -> u32 { self.speech_ms }
+    pub fn silence_ms(&self) -> u32 { self.silence_ms }
+
+    pub fn had_speech(&self) -> bool { self.speech_ms > 0 }
+}

crates/jarvis-core/src/audio_processing/vad/webrtc.rs

@@ -0,0 +1,49 @@
+use webrtc_vad::{SampleRate, Vad, VadMode};
+
+use crate::config;
+
+pub const FRAME_SAMPLES: usize = 480;
+pub const FRAME_MS: u32 = 30;
+
+pub struct WebRtcVad {
+    inner: Vad,
+    buf: Vec<i16>,
+}
+
+impl WebRtcVad {
+    pub fn new() -> Self {
+        Self::with_aggressiveness(config::VAD_AGGRESSIVENESS)
+    }
+
+    pub fn with_aggressiveness(level: u8) -> Self {
+        let mode = match level {
+            0 => VadMode::Quality,
+            1 => VadMode::LowBitrate,
+            2 => VadMode::Aggressive,
+            _ => VadMode::VeryAggressive,
+        };
+        Self {
+            inner: Vad::new_with_rate_and_mode(SampleRate::Rate16kHz, mode),
+            buf: Vec::with_capacity(FRAME_SAMPLES * 2),
+        }
+    }
+
+    pub fn push_samples(&mut self, samples: &[i16]) -> Vec<bool> {
+        self.buf.extend_from_slice(samples);
+        let mut out = Vec::new();
+        while self.buf.len() >= FRAME_SAMPLES {
+            let frame: Vec<i16> = self.buf.drain(..FRAME_SAMPLES).collect();
+            let is_speech = self.inner.is_voice_segment(&frame).unwrap_or(false);
+            out.push(is_speech);
+        }
+        out
+    }
+
+    pub fn reset(&mut self) {
+        self.buf.clear();
+    }
+}
+
+impl Default for WebRtcVad {
+    fn default() -> Self { Self::new() }
+}