feat(ios,p0): iOS P0 platform, audio fixes, channel UX

crates/chanora_audio/src/engine.rs

@@ -216,12 +216,7 @@ impl AudioEngine {
         // other platform stays on the cpal / SDL flow below.
         #[cfg(target_os = "ios")]
         {
-            return Self::start_with_gate_ios(
-                cfg,
-                voice_out_tx,
-                voice_in_rx,
-                transmit_gate,
-            );
+            return Self::start_with_gate_ios(cfg, voice_out_tx, voice_in_rx, transmit_gate);
         }
         #[cfg(not(target_os = "ios"))]
         {
@@ -684,6 +679,55 @@ impl AudioEngine {
         info!(target: "chanora_audio", "audio engine stopped");
     }
 
+    /// iOS-only: restart the underlying VoiceProcessingIO unit after
+    /// route changes.
+    pub fn ios_restart_voice_unit(&self) -> Result<(), AudioError> {
+        #[cfg(target_os = "ios")]
+        {
+            let mut guard = self._ios_voice_unit.lock().unwrap();
+            let unit = guard
+                .as_mut()
+                .ok_or_else(|| AudioError::Backend("ios voice unit not running".to_string()))?;
+            return unit.restart();
+        }
+        #[cfg(not(target_os = "ios"))]
+        {
+            Ok(())
+        }
+    }
+
+    /// iOS-only: pause the underlying VoiceProcessingIO unit.
+    pub fn ios_pause_voice_unit(&self) -> Result<(), AudioError> {
+        #[cfg(target_os = "ios")]
+        {
+            let mut guard = self._ios_voice_unit.lock().unwrap();
+            let unit = guard
+                .as_mut()
+                .ok_or_else(|| AudioError::Backend("ios voice unit not running".to_string()))?;
+            return unit.pause();
+        }
+        #[cfg(not(target_os = "ios"))]
+        {
+            Ok(())
+        }
+    }
+
+    /// iOS-only: resume the underlying VoiceProcessingIO unit.
+    pub fn ios_resume_voice_unit(&self) -> Result<(), AudioError> {
+        #[cfg(target_os = "ios")]
+        {
+            let mut guard = self._ios_voice_unit.lock().unwrap();
+            let unit = guard
+                .as_mut()
+                .ok_or_else(|| AudioError::Backend("ios voice unit not running".to_string()))?;
+            return unit.resume();
+        }
+        #[cfg(not(target_os = "ios"))]
+        {
+            Ok(())
+        }
+    }
+
     /// Set the **transmission gate** (SRS-201). When true the
     /// encoder feed is allowed to emit Opus frames; when false the
     /// captured audio is discarded before encoding. This is the
@@ -768,8 +812,7 @@ impl AudioEngine {
     /// sensible range internally.
     pub fn set_output_gain(&self, gain: f32) {
         let clamped = gain.clamp(0.0, 4.0);
-        self.output_gain
-            .store(clamped.to_bits(), Ordering::Relaxed);
+        self.output_gain.store(clamped.to_bits(), Ordering::Relaxed);
     }
 
     /// Current master output gain.
@@ -818,12 +861,8 @@ fn try_open_capture(
         in_stream_cfg.buffer_size = cpal::BufferSize::Default;
     }
 
-    let mut opus_enc = OpusEncoder::new(
-        OpusSampleRate::Hz48000,
-        OpusChannels::Mono,
-        OpusApp::Voip,
-    )
-    .map_err(|e| AudioError::Opus(format!("encoder new: {e}")))?;
+    let mut opus_enc = OpusEncoder::new(OpusSampleRate::Hz48000, OpusChannels::Mono, OpusApp::Voip)
+        .map_err(|e| AudioError::Opus(format!("encoder new: {e}")))?;
 
     // Opus VOIP tuning. Defaults give us 'auto' bitrate (can drop
     // to ~6 kbps during silence \u2014 which sounds garbled when
@@ -1147,13 +1186,12 @@ where
     // `same_rate` is the common case where the device is already at
     // 48 kHz — bypass the resampler entirely.
     let same_rate = dev_sample_rate == SAMPLE_RATE;
-    let resample_state: Arc<Mutex<PlaybackResampleState>> = Arc::new(Mutex::new(
-        PlaybackResampleState {
+    let resample_state: Arc<Mutex<PlaybackResampleState>> =
+        Arc::new(Mutex::new(PlaybackResampleState {
             pos: 0.0,
             last_l: 0.0,
             last_r: 0.0,
-        },
-    ));
+        }));
     // Reusable scratch buffer for 48 kHz stereo samples coming out
     // of AudioHandler. Allocating a fresh `Vec` per cpal callback on
     // glibc malloc was costing measurable time on the realtime audio