portapack-mayhem/firmware/baseband/audio_output.hpp

/*
 * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 * Copyright (C) 2024 Mark Thompson
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __AUDIO_OUTPUT_H__
#define __AUDIO_OUTPUT_H__

#include "dsp_types.hpp"

#include "dsp_iir.hpp"
#include "dsp_squelch.hpp"

#include "stream_input.hpp"
#include "block_decimator.hpp"
#include "audio_stats_collector.hpp"

#include <cstdint>
#include <memory>

class AudioOutput {
   public:
    void configure(const bool do_proc);

    void configure(
        const iir_biquad_config_t& hpf_config,
        const iir_biquad_config_t& deemph_config = iir_config_passthrough,
        const float squelch_threshold = 0.0f);

    void write_unprocessed(const buffer_s16_t& audio);
    void write(const buffer_s16_t& audio);
    void write(const buffer_f32_t& audio);

    void set_stream(std::unique_ptr<StreamInput> new_stream) {
        stream = std::move(new_stream);
    }

    bool is_squelched();

   private:
    static constexpr float k = 32768.0f;
    static constexpr float ki = 1.0f / k;

    BlockDecimator<int16_t, 32> block_buffer_s16{1};
    BlockDecimator<float, 32> block_buffer{1};

    IIRBiquadFilter hpf{};
    IIRBiquadFilter deemph{};
    FMSquelch squelch{};

    std::unique_ptr<StreamInput> stream{};

    AudioStatsCollector audio_stats{};

    uint64_t audio_present_history = 0;

    bool audio_present = false;
    bool do_processing = true;

    void on_block(const buffer_f32_t& audio);

    void fill_audio_buffer(const buffer_s16_t& audio, const bool send_to_fifo);
    void fill_audio_buffer(const buffer_f32_t& audio, const bool send_to_fifo);

    void feed_audio_stats(const buffer_s16_t& audio);
    void feed_audio_stats(const buffer_f32_t& audio);
};

#endif /*__AUDIO_OUTPUT_H__*/