feat: AudioResampler (#66)

webrtc-sys/include/livekit/audio_resampler.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2023 LiveKit
+ *
+ * Licensed under the Apache License, Version 2.0 (the “License”);
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an “AS IS” BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <memory>
+
+#include "api/audio/audio_frame.h"
+#include "api/data_channel_interface.h"
+#include "common_audio/resampler/include/push_resampler.h"
+#include "livekit/webrtc.h"
+#include "rust/cxx.h"
+
+namespace livekit {
+
+class AudioResampler {
+ public:
+  size_t remix_and_resample(const int16_t* src,
+                            size_t samples_per_channel,
+                            size_t num_channels,
+                            int sample_rate_hz,
+                            size_t dest_num_channels,
+                            int dest_sample_rate_hz);
+
+  const int16_t* data() const;
+
+ private:
+  webrtc::AudioFrame frame_;
+  webrtc::PushResampler<int16_t> resampler_;
+};
+
+std::unique_ptr<AudioResampler> create_audio_resampler();
+
+}  // namespace livekit