utun2/tools/chatgui/src/audiocompressor.h

#pragma once

#include <vector>
#include <deque>
#include <cstdint>

class AudioCompressor {
public:
    struct Config {
        int sampleRate = 48000;
        int channels = 1;
        int blockDurationMs = 20;
        int lookbackMs = 200;
        int lookaheadMs = 100;
        float maxGainDb = 30.0f;
        float riseRatePer500ms = 2.0f;
        float targetLevel = 0.25f;
    };

    void configure(const Config& cfg);
    void reset();

    void setEnabled(bool enabled) { m_enabled = enabled; }
    bool isEnabled() const { return m_enabled; }

    void push(const int16_t* samples, size_t count);
    const std::vector<int16_t>& outputBuffer() const { return m_output; }
    bool hasPending() const { return !m_pending.empty() || !m_accumulator.empty(); }
    void flush();

private:
    Config m_cfg;
    bool m_enabled = true;

    struct BlockLevel {
        float level;
    };
    std::deque<BlockLevel> m_blockLevels;

    struct PendingBlock {
        std::vector<int16_t> samples;
        size_t levelIndex;
    };
    std::deque<PendingBlock> m_pending;
    std::vector<int16_t> m_accumulator;

    std::vector<int16_t> m_output;

    int m_blockSamples = 960;
    int m_lookbackBlocks = 10;
    int m_lookaheadBlocks = 5;
    float m_riseFactorPerBlock = 1.0f;
    float m_maxGain = 31.62f;
    float m_gainSmoothed = 1.0f;
    int m_dbgCounter = 0;

    float computeBlockLevel(const int16_t* samples, size_t count) const;
    void processPendingBlock();
};