feat(native): mix the input and output audio (#11037)

2026-08-21 03:51:45 +08:00 · 2025-03-20 13:11:27 +00:00
parent fad49bb070
commit aa620af40f
12 changed files with 454 additions and 499 deletions
@@ -0,0 +1,104 @@
+use std::{ffi::c_void, mem::size_of};
+
+use core_foundation::string::CFString;
+use coreaudio::sys::{
+  kAudioObjectPropertyElementMain, kAudioObjectPropertyScopeGlobal, AudioObjectGetPropertyData,
+  AudioObjectID, AudioObjectPropertyAddress,
+};
+use rubato::{Resampler, SincFixedIn, SincInterpolationParameters, SincInterpolationType};
+
+use crate::error::CoreAudioError;
+
+pub fn cfstring_from_bytes_with_nul(bytes: &[u8]) -> CFString {
+  CFString::new(
+    unsafe { std::ffi::CStr::from_bytes_with_nul_unchecked(bytes) }
+      .to_string_lossy()
+      .as_ref(),
+  )
+}
+
+pub fn get_global_main_property<T: Sized>(
+  id: AudioObjectID,
+  selector: u32,
+  data: *mut T,
+) -> Result<(), CoreAudioError> {
+  unsafe {
+    let address = AudioObjectPropertyAddress {
+      mSelector: selector,
+      mScope: kAudioObjectPropertyScopeGlobal,
+      mElement: kAudioObjectPropertyElementMain,
+    };
+
+    let mut data_size = size_of::<T>() as u32;
+
+    let status = AudioObjectGetPropertyData(
+      id,
+      &address as *const AudioObjectPropertyAddress,
+      0,
+      std::ptr::null(),
+      &mut data_size,
+      data.cast(),
+    );
+
+    if status != 0 {
+      return Err(CoreAudioError::GetPropertyDataFailed(status));
+    }
+
+    Ok(())
+  }
+}
+
+pub fn process_audio_frame(
+  m_data: *mut c_void,
+  m_data_byte_size: u32,
+  m_number_channels: u32,
+  current_sample_rate: f64,
+  target_sample_rate: f64,
+) -> Option<Vec<f32>> {
+  // Only create slice if we have valid data
+  if m_data.is_null() || m_data_byte_size == 0 {
+    return None;
+  }
+  // Calculate total number of samples (total bytes / bytes per sample)
+  let total_samples = m_data_byte_size as usize / 4; // 4 bytes per f32
+
+  // Create a slice of all samples
+  let samples: &[f32] = unsafe { std::slice::from_raw_parts(m_data.cast::<f32>(), total_samples) };
+
+  // Check the channel count and data format
+  let channel_count = m_number_channels as usize;
+
+  let processed_samples = if channel_count > 1 {
+    // For stereo, samples are interleaved: [L, R, L, R, ...]
+    // We need to average each pair to get mono
+    samples
+      .chunks(channel_count)
+      .map(|chunk| chunk.iter().sum::<f32>() / channel_count as f32)
+      .collect()
+  } else {
+    // For mono, just copy the samples
+    samples.to_vec()
+  };
+
+  if current_sample_rate != target_sample_rate {
+    let params = SincInterpolationParameters {
+      sinc_len: 256,
+      f_cutoff: 0.95,
+      interpolation: SincInterpolationType::Linear,
+      oversampling_factor: 256,
+      window: rubato::WindowFunction::BlackmanHarris2,
+    };
+    let mut resampler = SincFixedIn::<f32>::new(
+      target_sample_rate / current_sample_rate,
+      2.0,
+      params,
+      processed_samples.len(),
+      1,
+    )
+    .ok()?;
+    let mut waves_out = resampler.process(&[processed_samples], None).ok()?;
+    waves_out.pop()
+  } else {
+    Some(processed_samples)
+  }
+}