Merge pull request #104 from kslr/main

fix: 修正Amlogic A113X PDM 24→16 位对齐导致的约 -48 dB 衰减

packages/client-rust/src/services/audio/record.rs

@@ -16,6 +16,8 @@ enum State {
     Recording,
 }
 
+const A113_CAPTURE_BITS_PER_SAMPLE: u16 = 32;
+
 pub struct AudioRecorder {
     state: Arc<Mutex<State>>,
     arecord_thread: Arc<Mutex<Option<Child>>>,
@@ -69,45 +71,34 @@ impl AudioRecorder {
             return Ok(());
         }
 
-        let config = config.unwrap_or_else(|| (*AUDIO_CONFIG).clone());
+        let requested_config = config.unwrap_or_else(|| (*AUDIO_CONFIG).clone());
-
+        let capture_config = capture_config_for_recording(&requested_config);
-        let mut arecord_thread = Command::new("arecord")
+        let mut arecord_thread = spawn_arecord(&capture_config)?;
-            .args([
-                "--quiet",
-                "-t",
-                "raw",
-                "-D",
-                &config.pcm,
-                "-f",
-                &format!("S{}_LE", config.bits_per_sample),
-                "-r",
-                &config.sample_rate.to_string(),
-                "-c",
-                &config.channels.to_string(),
-                "--buffer-size",
-                &config.buffer_size.to_string(),
-                "--period-size",
-                &config.period_size.to_string(),
-            ])
-            .stdout(Stdio::piped())
-            .spawn()?;
 
         let mut stdout = arecord_thread.stdout.take().unwrap();
         let read_thread = tokio::spawn(async move {
-            let size = (config.bits_per_sample / 8) as usize;
+            let bytes_per_sample = (capture_config.bits_per_sample.max(8) / 8) as usize;
-            let target_size = config.buffer_size as usize * size;
+            let bytes_per_frame = bytes_per_sample * capture_config.channels.max(1) as usize;
+            let target_frames = capture_config.buffer_size.max(1) as usize;
+            let read_frames = capture_config.period_size.max(1) as usize;
+            let target_size = target_frames * bytes_per_frame;
+            let read_size = read_frames * bytes_per_frame;
 
             let mut accumulated_data = Vec::new();
-            let mut buffer = vec![0u8; config.period_size as usize * size];
+            let mut buffer = vec![0u8; read_size];
 
             loop {
                 match stdout.read(&mut buffer).await {
                     Ok(size) if size > 0 => {
                         accumulated_data.extend_from_slice(&buffer[..size]);
-                        if accumulated_data.len() >= target_size {
+                        while accumulated_data.len() >= target_size {
                             let data_to_send =
                                 accumulated_data.drain(..target_size).collect::<Vec<u8>>();
-                            let _ = on_stream(data_to_send).await;
+                            let data_to_send =
+                                transform_stream_chunk(data_to_send, &requested_config, &capture_config);
+                            if !data_to_send.is_empty() {
+                                let _ = on_stream(data_to_send).await;
+                            }
                         }
                     }
                     _ => break,
@@ -124,3 +115,71 @@ impl AudioRecorder {
         Ok(())
     }
 }
+
+fn capture_config_for_recording(requested: &AudioConfig) -> AudioConfig {
+    let mut capture = requested.clone();
+    if requested.bits_per_sample == 16 {
+        capture.bits_per_sample = A113_CAPTURE_BITS_PER_SAMPLE;
+    }
+    capture
+}
+
+fn transform_stream_chunk(
+    chunk: Vec<u8>,
+    requested: &AudioConfig,
+    capture: &AudioConfig,
+) -> Vec<u8> {
+    if requested.bits_per_sample != 16 || capture.bits_per_sample != A113_CAPTURE_BITS_PER_SAMPLE {
+        return chunk;
+    }
+    convert_a113_s32_to_s16(&chunk)
+}
+
+fn convert_a113_s32_to_s16(chunk: &[u8]) -> Vec<u8> {
+    if chunk.len() % 4 != 0 {
+        return Vec::new();
+    }
+
+    let frame_count = chunk.len() / 4;
+    let mut out = vec![0u8; frame_count * 2];
+
+    for frame in 0..frame_count {
+        let base = frame * 4;
+        let sample = i32::from_le_bytes([
+            chunk[base],
+            chunk[base + 1],
+            chunk[base + 2],
+            chunk[base + 3],
+        ]);
+        // A113 PDM data lives in lower 24 bits of S32_LE: shift by 8 (not 16).
+        let mapped = (sample >> 8).clamp(i16::MIN as i32, i16::MAX as i32) as i16;
+        let out_base = frame * 2;
+        out[out_base..out_base + 2].copy_from_slice(&mapped.to_le_bytes());
+    }
+
+    out
+}
+
+fn spawn_arecord(config: &AudioConfig) -> Result<Child, AppError> {
+    let child = Command::new("arecord")
+        .args([
+            "--quiet",
+            "-t",
+            "raw",
+            "-D",
+            &config.pcm,
+            "-f",
+            &format!("S{}_LE", config.bits_per_sample),
+            "-r",
+            &config.sample_rate.to_string(),
+            "-c",
+            &config.channels.to_string(),
+            "--buffer-size",
+            &config.buffer_size.to_string(),
+            "--period-size",
+            &config.period_size.to_string(),
+        ])
+        .stdout(Stdio::piped())
+        .spawn()?;
+    Ok(child)
+}