Recorder rewritten. + Attempt to integrate cpal and portaudio.

src-tauri/src/recorder/pvrecorder.rs

@@ -0,0 +1,105 @@
+use pv_recorder::{Recorder, RecorderBuilder};
+use log::{info, warn, error};
+
+use once_cell::sync::OnceCell;
+use std::sync::Arc;
+use arc_swap::ArcSwap;
+use std::sync::atomic::{AtomicBool, AtomicI32, AtomicU32, Ordering};
+ 
+static RECORDER: OnceCell<ArcSwap<Recorder>> = OnceCell::new();
+static SELECTED_MICROPHONE_IDX: AtomicI32 = AtomicI32::new(0);
+static FRAME_LENGTH: AtomicU32 = AtomicU32::new(0);
+static IS_RECORDING: AtomicBool = AtomicBool::new(false);
+
+pub fn init_microphone(device_index: i32, frame_length: u32) -> bool {
+    match RECORDER.get().is_none() {
+        true => {
+            let pv_recorder = RecorderBuilder::new()
+                .device_index(device_index)
+                .frame_length(frame_length as i32)
+                .init();
+
+            match pv_recorder {
+                Ok(pv) => {
+                    // store
+                    RECORDER.set(ArcSwap::from_pointee(pv));
+
+                    // remember current configuration
+                    SELECTED_MICROPHONE_IDX.store(device_index, Ordering::SeqCst);
+                    FRAME_LENGTH.store(frame_length, Ordering::SeqCst);
+
+                    // success
+                    true
+                },
+                Err(msg) => {
+                    error!("Failed to initialize pvrecorder.\nError details: {:?}", msg);
+
+                    // fail
+                    false
+                }
+            }
+        },
+        _ => {
+            // check if re-initialization required (i.e. selecetd microphoneor frame-length was changed )
+            if SELECTED_MICROPHONE_IDX.load(Ordering::SeqCst) != device_index
+               ||
+               RECORDER.get().unwrap().load().frame_length() != frame_length as usize {
+                warn!("Selected microphone or frame length was changed, re-initializing ...");
+                // initialize again with new device index
+                if IS_RECORDING.load(Ordering::SeqCst) {
+                    // RECORDER.get().unwrap().load().stop().expect("Failed to start audio recording!");
+                    stop_recording();
+                }
+
+                // remember new configuration
+                SELECTED_MICROPHONE_IDX.store(device_index, Ordering::SeqCst);
+                FRAME_LENGTH.store(frame_length, Ordering::SeqCst);
+
+                // store
+                RECORDER.get().unwrap().store(Arc::new(RecorderBuilder::new()
+                    .device_index(device_index)
+                    .frame_length(frame_length as i32)
+                    .init()
+                    .expect("Failed to initialize pvrecorder")));
+            }
+
+            // success
+            true
+        }
+    }
+}
+
+pub fn read_microphone(frame_buffer: &mut [i16]) {
+    // ensure microphone is initialized
+    if !RECORDER.get().is_none() {
+        // read to frame buffer
+        match RECORDER.get().unwrap().load().read(frame_buffer) {
+            Err(msg) => {
+                // @TODO: Fix somehow. PvRecorder always wait for PCM buffer size of 512.
+                // error!("Failed to read audio frame. {:?}", msg);
+                // eprintln!("Failed to read audio frame. {:?}", msg);
+            },
+            _ => ()
+        }
+    }
+}
+
+pub fn start_recording(device_index: i32, frame_length: u32) {
+    // ensure microphone is initialized
+    init_microphone(device_index, frame_length);
+
+    // start recording
+    RECORDER.get().unwrap().load().start().expect("Failed to start audio recording!");
+    IS_RECORDING.store(true, Ordering::SeqCst);
+    info!("START recording from microphone ...");
+}
+
+pub fn stop_recording() {
+    // ensure microphone is initialized
+    if !RECORDER.get().is_none() && IS_RECORDING.load(Ordering::SeqCst) {
+        // stop recording
+        RECORDER.get().unwrap().load().stop().expect("Failed to stop audio recording!");
+        IS_RECORDING.store(false, Ordering::SeqCst);
+        info!("STOP recording from microphone ...");
+    }
+}