audio_processor.h

// Copyright (C) 2025 Alexandre St-Onge
// SPDX-License-Identifier: MIT
#pragma once
 
#include "audio_buffer.h"
 
#include <nlohmann/json.hpp>
 
#include <cstdint>
#include <memory>
#include <vector>
 
namespace sfFDN
{
class AudioProcessor
{
  public:
    AudioProcessor() = default;
    virtual ~AudioProcessor() = default;
 
    virtual void Process(const AudioBuffer& input, AudioBuffer& output) noexcept = 0;
 
    virtual uint32_t InputChannelCount() const = 0;
 
    virtual uint32_t OutputChannelCount() const = 0;
 
    virtual void Clear() = 0;
 
    virtual std::unique_ptr<AudioProcessor> Clone() const = 0;
};
 
class AudioProcessorChain : public AudioProcessor
{
  public:
    AudioProcessorChain(uint32_t block_size);
 
    bool AddProcessor(std::unique_ptr<AudioProcessor>&& processor);
 
    uint32_t GetProcessorCount() const;
 
    AudioProcessor* GetProcessor(uint32_t index) const;
 
    void Process(const AudioBuffer& input, AudioBuffer& output) noexcept override;
 
    uint32_t InputChannelCount() const override;
 
    uint32_t OutputChannelCount() const override;
 
    void Clear() override;
 
    std::unique_ptr<AudioProcessor> Clone() const override;
 
  private:
    uint32_t block_size_ = 0;
    std::vector<std::unique_ptr<AudioProcessor>> processors_;
 
    std::vector<float> work_buffer_a_;
    std::vector<float> work_buffer_b_;
    uint32_t max_work_buffer_size_ = 0;
 
    void ProcessInternal(const AudioBuffer& input, AudioBuffer& output) noexcept;
};
} // namespace sfFDN