audio_resampler.h

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#pragma once
 
#ifdef USE_ESP32
 
#include "audio.h"
#include "audio_transfer_buffer.h"
 
#include "esphome/components/ring_buffer/ring_buffer.h"
#include "esphome/core/defines.h"
#include "esphome/core/helpers.h"
 
#ifdef USE_SPEAKER
#include "esphome/components/speaker/speaker.h"
#endif
 
#include "esp_err.h"
 
#include <resampler.h>  // esp-audio-libs
 
namespace esphome::audio {
 
enum class AudioResamplerState : uint8_t {
  RESAMPLING,  // More data is available to resample
  FINISHED,    // All file data has been resampled and transferred
  FAILED,      // Failed to allocate the audio source
};
 
class AudioResampler {
  /*
   * @brief Class that facilitates resampling audio.
   * The audio data is read from a ring buffer source, resampled, and sent to an audio sink (ring buffer or speaker
   * component). Also supports converting bits per sample.
   */
 public:
  AudioResampler(size_t input_buffer_size, size_t output_buffer_size);
 
  esp_err_t add_source(std::weak_ptr<ring_buffer::RingBuffer> &input_ring_buffer);
 
  esp_err_t add_sink(std::weak_ptr<ring_buffer::RingBuffer> &output_ring_buffer);
 
#ifdef USE_SPEAKER
  esp_err_t add_sink(speaker::Speaker *speaker);
#endif
 
  esp_err_t start(AudioStreamInfo &input_stream_info, AudioStreamInfo &output_stream_info, uint16_t number_of_taps,
                  uint16_t number_of_filters);
 
  AudioResamplerState resample(bool stop_gracefully, int32_t *ms_differential);
 
  void set_pause_output_state(bool pause_state) { this->pause_output_ = pause_state; }
 
 protected:
  std::shared_ptr<ring_buffer::RingBuffer> source_ring_buffer_;
  std::unique_ptr<RingBufferAudioSource> audio_source_;
  std::unique_ptr<AudioSinkTransferBuffer> output_transfer_buffer_;
 
  size_t input_buffer_size_;
  size_t output_buffer_size_;
 
  uint32_t accumulated_frames_used_{0};
  uint32_t accumulated_frames_generated_{0};
 
  bool pause_output_{false};
 
  AudioStreamInfo input_stream_info_;
  AudioStreamInfo output_stream_info_;
 
  std::unique_ptr<esp_audio_libs::resampler::Resampler> resampler_;
};
 
}  // namespace esphome::audio
 
#endif