Function record_audio

tests/chat.cpp:62–123

}

bool record_audio(std::vector<uint8_t>& pcm_out) {
    if (SDL_Init(SDL_INIT_AUDIO) < 0) {
        std::cerr << "Failed to init SDL: " << SDL_GetError() << "\n";
        return false;
    }

    int num_devices = SDL_GetNumAudioDevices(1);
    if (num_devices == 0) {
        std::cerr << "No audio capture devices found\n";
        SDL_QuitSubSystem(SDL_INIT_AUDIO);
        return false;
    }

    SDL_AudioSpec want, have;
    SDL_zero(want);
    want.freq = RECORD_SAMPLE_RATE;
    want.format = AUDIO_S16LSB;
    want.channels = 1;
    want.samples = (RECORD_SAMPLE_RATE * 100) / 1000;
    want.callback = record_callback;

    SDL_AudioDeviceID device = SDL_OpenAudioDevice(nullptr, 1, &want, &have, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
    if (device == 0) {
        std::cerr << "Failed to open mic: " << SDL_GetError() << "\n";
        SDL_QuitSubSystem(SDL_INIT_AUDIO);
        return false;
    }

    g_record.actual_sample_rate = have.freq;
    g_record.buffer.clear();
    g_record.recording = true;
    SDL_PauseAudioDevice(device, 0);

    std::cout << "Recording... press Enter to stop.\n" << std::flush;

    std::atomic<bool> stop{false};
    std::thread input_thread([&stop]() {
        std::string line;
        std::getline(std::cin, line);
        stop = true;
    });

    while (!stop) {
        std::this_thread::sleep_for(std::chrono::milliseconds(50));
    }

    g_record.recording = false;
    SDL_PauseAudioDevice(device, 1);

    {
        std::lock_guard<std::mutex> lock(g_record.mutex);
        pcm_out = resample_s16(g_record.buffer, g_record.actual_sample_rate, RECORD_SAMPLE_RATE);
    }

    double duration = (pcm_out.size() / 2) / static_cast<double>(RECORD_SAMPLE_RATE);
    std::cout << "Recorded " << std::fixed << std::setprecision(1) << duration << "s of audio.\n";

    input_thread.join();