/* * Copyright 2018 The Android Open Source Project * * 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. */ #ifndef SHARED_MONOTOSTEREO_H #define SHARED_MONOTOSTEREO_H #include "IRenderableAudio.h" class MonoToStereo : public IRenderableAudio { public: MonoToStereo(IRenderableAudio *input) : mInput(input){}; void renderAudio(float *audioData, int32_t numFrames) override { constexpr int kChannelCountStereo = 2; mInput->renderAudio(audioData, numFrames); // We assume that audioData has sufficient frames to hold the stereo output, so copy each // frame in the input to the output twice, working our way backwards through the input array // e.g. 123 => 112233 for (int i = numFrames - 1; i >= 0; --i) { audioData[i * kChannelCountStereo] = audioData[i]; audioData[i * kChannelCountStereo + 1] = audioData[i]; } } IRenderableAudio *mInput; }; #endif //SHARED_MONOTOSTEREO_H