feat: AudioResampler (#66)

livekit-webrtc/src/lib.rs

@@ -46,6 +46,7 @@ pub mod video_stream;
 
 #[cfg(not(target_arch = "wasm32"))]
 pub mod native {
+    pub use crate::imp::audio_resampler;
     pub use crate::imp::yuv_helper;
     pub use webrtc_sys::webrtc::ffi::create_random_uuid;
 }

livekit-webrtc/src/native/audio_resampler.rs

@@ -0,0 +1,39 @@
+use cxx::UniquePtr;
+use webrtc_sys::audio_resampler as sys_ar;
+
+pub struct AudioResampler {
+    sys_handle: UniquePtr<sys_ar::ffi::AudioResampler>,
+}
+
+impl Default for AudioResampler {
+    fn default() -> Self {
+        Self {
+            sys_handle: sys_ar::ffi::create_audio_resampler(),
+        }
+    }
+}
+
+impl AudioResampler {
+    pub fn remix_and_resample(
+        &mut self,
+        src: &[i16],
+        samples_per_channel: u32,
+        num_channels: u32,
+        sample_rate: u32,
+        dst_num_channels: u32,
+        dst_sample_rate: u32,
+    ) -> &[i16] {
+        unsafe {
+            let len = self.sys_handle.pin_mut().remix_and_resample(
+                src.as_ptr(),
+                samples_per_channel as usize,
+                num_channels as usize,
+                sample_rate as i32,
+                dst_num_channels as usize,
+                dst_sample_rate as i32,
+            );
+
+            std::slice::from_raw_parts(self.sys_handle.data(), len)
+        }
+    }
+}

livekit-webrtc/src/native/mod.rs

@@ -1,3 +1,4 @@
+pub mod audio_resampler;
 pub mod audio_source;
 pub mod audio_stream;
 pub mod data_channel;