ambisonic_mixing_encoder_node.h

/*
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
 
    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 RESONANCE_AUDIO_GRAPH_AMBISONIC_MIXING_ENCODER_NODE_H_
#define RESONANCE_AUDIO_GRAPH_AMBISONIC_MIXING_ENCODER_NODE_H_
 
#include <vector>
 
#include "ambisonics/ambisonic_lookup_table.h"
#include "base/audio_buffer.h"
#include "base/spherical_angle.h"
#include "dsp/gain_mixer.h"
#include "graph/system_settings.h"
#include "node/processing_node.h"
 
namespace vraudio {
 
// Node that accepts single mono sound object buffer as input and encodes it
// into an Ambisonic sound field.
class AmbisonicMixingEncoderNode : public ProcessingNode {
 public:
  // Initializes AmbisonicMixingEncoderNode class.
  //
  // @param system_settings Global system configuration.
  // @param lookup_table Ambisonic encoding lookup table.
  // @param ambisonic_order Order of Ambisonic sources.
  AmbisonicMixingEncoderNode(const SystemSettings& system_settings,
                             const AmbisonicLookupTable& lookup_table,
                             int ambisonic_order);
 
  // Node implementation.
  bool CleanUp() final {
    CallCleanUpOnInputNodes();
    // Prevent node from being disconnected when all sources are removed.
    return false;
  }
 
 protected:
  // Implements ProcessingNode.
  const AudioBuffer* AudioProcess(const NodeInput& input) override;
 
 private:
  const SystemSettings& system_settings_;
  const AmbisonicLookupTable& lookup_table_;
 
  // Ambisonic order of encoded sources.
  const int ambisonic_order_;
 
  // |GainMixer| instance.
  GainMixer gain_mixer_;
 
  // Encoding coefficient values to be applied to encode the input.
  std::vector<float> coefficients_;
};
 
}  // namespace vraudio
 
#endif  // RESONANCE_AUDIO_GRAPH_AMBISONIC_MIXING_ENCODER_NODE_H_