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/*
Copyright 2018 Google Inc. All Rights Reserved.
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
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.
*/
#include "dsp/mixer.h"
#include "base/logging.h"
namespace vraudio {
Mixer::Mixer(size_t target_num_channels, size_t frames_per_buffer)
: output_(target_num_channels, frames_per_buffer), is_empty_(false) {
Reset();
}
void Mixer::AddInput(const AudioBuffer& input) {
DCHECK_EQ(input.num_frames(), output_.num_frames());
// Accumulate the input buffers into the output buffer.
const size_t num_channels =
std::min(input.num_channels(), output_.num_channels());
for (size_t n = 0; n < num_channels; ++n) {
if (input[n].IsEnabled()) {
output_[n] += input[n];
}
}
is_empty_ = false;
}
const AudioBuffer* Mixer::GetOutput() const {
if (is_empty_) {
return nullptr;
}
return &output_;
}
void Mixer::Reset() {
if (!is_empty_) {
output_.Clear();
}
is_empty_ = true;
}
} // namespace vraudio