added audio_processing.rs

Author: xianshijing-lk

examples/agent_audio_latency/src/audio_processing.rs

@@ -0,0 +1,55 @@
+use livekit::webrtc::native::apm::AudioProcessingModule;
+use log::warn;
+use std::sync::Mutex;
+
+const APM_STREAM_DELAY_MS: i32 = 50;
+
+pub struct SharedAudioProcessing {
+    apm: Mutex<AudioProcessingModule>,
+    sample_rate: u32,
+    num_channels: i32,
+}
+
+impl SharedAudioProcessing {
+    pub fn new(sample_rate: u32, num_channels: i32) -> Self {
+        let mut apm = AudioProcessingModule::new(
+            true,  // echo cancellation
+            false, // AGC disabled by request
+            true,  // high-pass filter
+            true,  // noise suppression
+        );
+        if let Err(err) = apm.set_stream_delay_ms(APM_STREAM_DELAY_MS) {
+            warn!("APM set_stream_delay_ms failed: {err}");
+        }
+
+        Self { apm: Mutex::new(apm), sample_rate, num_channels }
+    }
+
+    pub fn process_capture(&self, data: &mut [i16]) {
+        if data.is_empty() {
+            return;
+        }
+
+        if let Err(err) = self.apm.lock().unwrap().process_stream(
+            data,
+            self.sample_rate as i32,
+            self.num_channels,
+        ) {
+            warn!("APM process_stream failed: {err}");
+        }
+    }
+
+    pub fn process_render(&self, data: &mut [i16]) {
+        if data.is_empty() {
+            return;
+        }
+
+        if let Err(err) = self.apm.lock().unwrap().process_reverse_stream(
+            data,
+            self.sample_rate as i32,
+            self.num_channels,
+        ) {
+            warn!("APM process_reverse_stream failed: {err}");
+        }
+    }
+}