void irmeasure_process(t_irmeasure *x, t_symbol *sym, short argc, t_atom *argv)
{
    FFT_SETUP_D fft_setup;

    FFT_SPLIT_COMPLEX_D spectrum_1;
    FFT_SPLIT_COMPLEX_D spectrum_2;
    FFT_SPLIT_COMPLEX_D spectrum_3;

    void *measurement_rec;
    void *rec_mem;
    double *excitation_sig;
    double *out_buf;
    double *out_mem;
    float *filter_in;

    t_symbol *filter = filter_retriever(x->deconvolve_filter_specifier);

    double filter_specifier[HIRT_MAX_SPECIFIER_ITEMS];
    double range_specifier[HIRT_MAX_SPECIFIER_ITEMS];

    double test_pow;
    double max_pow;
    double sample_rate = x->sample_rate;
    double deconvolve_phase = phase_retriever(x->deconvolve_phase);

    long deconvolve_mode = x->deconvolve_mode;
    long bandlimit = x->measure_mode == SWEEP ? x->bandlimit : 0;

    AH_SIntPtr rec_length = x->T2;
    AH_SIntPtr gen_length = 0;
    AH_SIntPtr filter_length = buffer_length(filter);

    AH_UIntPtr fft_size;
    AH_UIntPtr fft_size_log2;
    AH_UIntPtr mem_size;
    AH_UIntPtr i;

    t_ess sweep_params;
    t_mls max_length_params;
    t_noise_params noise_params;

    switch (x->measure_mode)
    {
        case SWEEP:
            ess_params(&sweep_params, x->sweep_params.rf1, x->sweep_params.rf2, x->sweep_params.fade_in, x->sweep_params.fade_out, x->sweep_params.RT, x->sweep_params.sample_rate, x->inv_amp ? x->sweep_params.amp : 1, x->amp_curve);
            gen_length = ess_get_length(&sweep_params);
            break;

        case MLS:

            mls_params(&max_length_params, x->max_length_params.order, x->inv_amp ? x->max_length_params.amp : 1);
            gen_length = mls_get_length(&max_length_params);

            break;

        case NOISE:

            coloured_noise_params(&noise_params, x->noise_params.mode, x->noise_params.fade_in, x->noise_params.fade_out, x->noise_params.RT, x->noise_params.sample_rate,   x->inv_amp ? x->noise_params.amp : 1);
            gen_length = coloured_noise_get_length(&noise_params);
            break;
    }

    // Check and calculate lengths

    fft_size = calculate_fft_size(rec_length + gen_length, &fft_size_log2);

    // Allocate Temporary Memory

    fft_setup = hisstools_create_setup_d(fft_size_log2);

    excitation_sig = (double *)  malloc(gen_length * sizeof(double));

    spectrum_1.realp = ALIGNED_MALLOC((sizeof(double) * fft_size * 4));
    spectrum_1.imagp = spectrum_1.realp + (fft_size >> 1);
    spectrum_2.realp = spectrum_1.imagp + (fft_size >> 1);
    spectrum_2.imagp = spectrum_2.realp + (fft_size >> 1);
    spectrum_3.realp = spectrum_2.imagp + (fft_size >> 1);
    spectrum_3.imagp = spectrum_3.realp + fft_size;

    filter_in = filter_length ? (float *) ALIGNED_MALLOC(sizeof(float) * filter_length) : 0;

    if (!fft_setup || !excitation_sig || !spectrum_1.realp || (filter_length && !filter_in))
    {
        object_error ((t_object *) x, "could not allocate temporary memory for processing");

        hisstools_destroy_setup_d(fft_setup);
        free(excitation_sig);
        ALIGNED_FREE(spectrum_1.realp);
        ALIGNED_FREE(filter_in);

        return;
    }

    // Allocate output memory and get record memory

    rec_mem = access_mem_swap(&x->rec_mem, &mem_size);
    out_mem = grow_mem_swap(&x->out_mem, fft_size * x->current_num_active_ins * sizeof(double), fft_size * x->current_num_active_ins);

    if (!out_mem)
    {
        object_error ((t_object *) x, "could not allocate memory for output storage");
        free(excitation_sig);
        hisstools_destroy_setup_d(fft_setup);
        return;
    }

    // Generate Signal

    switch (x->measure_mode)
    {
        case SWEEP:
            ess_gen(&sweep_params, excitation_sig, true);
            break;

        case MLS:
            mls_gen(&max_length_params, excitation_sig, true);
            break;

        case NOISE:
            coloured_noise_gen(&noise_params, excitation_sig, true);
            break;
    }

    // Transform excitation signal into complex spectrum 2

    time_to_halfspectrum_double(fft_setup, excitation_sig, gen_length, spectrum_2, fft_size);

    if (bandlimit)
    {
        // Calculate standard filter for bandlimited deconvolution (sweep * inv sweep)

        ess_igen(&sweep_params, excitation_sig, INVERT_ALL, true);
        time_to_halfspectrum_double(fft_setup, excitation_sig, gen_length, spectrum_3, fft_size);
        convolve(spectrum_3, spectrum_2, fft_size, SPECTRUM_REAL);

        // Calculate full power spectrum from half spectrum - convert filter to have the required phase

        power_full_spectrum_from_half_spectrum(spectrum_3, fft_size);
        variable_phase_from_power_spectrum(fft_setup, spectrum_3, fft_size, deconvolve_phase, true);

        // Convert back to real format

        spectrum_3.imagp[0] = spectrum_3.realp[fft_size >> 1];
    }
    else
    {
        // Find maximum power to scale

        for (i = 1, max_pow = 0; i < (fft_size >> 1); i++)
void irextract_noise (t_irextract *x, t_symbol *sym, long argc, t_atom *argv)
{
	double length = 10000;
	double fade_in = 10;
	double fade_out = 10;
	double amp_comp = 1.;
	double out_length = 0;
	double max_pink, max_brown;
	double sample_rate;
	
	t_atom_long num_channels = 1;

	t_symbol *rec_buffer = 0;
	
	t_noise_mode noise_mode = NOISE_MODE_WHITE;
	
	if (sym == gensym("brown"))
		noise_mode = NOISE_MODE_BROWN;
	if (sym == gensym("pink"))
		noise_mode = NOISE_MODE_PINK;
		
	// Load parameters
	
	if (argc > 0)
	{
		rec_buffer = atom_getsym(argv++);
		sample_rate = buffer_sample_rate(rec_buffer);
	}
	if (argc > 1)
		length = atom_getfloat(argv++);
	if (argc > 2)
		fade_in = atom_getfloat(argv++);
	if (argc > 3)
		fade_out = atom_getfloat(argv++);
	if (argc > 4)
		num_channels = atom_getlong(argv++);
	if (argc > 5)
		out_length = atom_getfloat(argv++);
	
	// Check parameters
	
	if (!rec_buffer)
	{
		object_error((t_object *)x, "no buffer given");
		return;
	}
	
	length = irextract_param_check(x, "length", length, 0., HUGE_VAL);
	fade_in = irextract_param_check(x, "fade in time", fade_in, 0., length / 2);
	fade_out = irextract_param_check(x, "fade out time", fade_out, 0., length / 2);
	num_channels = (t_atom_long) irextract_param_check(x, "number of channels", (double) num_channels, 1, HIRT_MAX_MEASURE_CHANS);
	x->out_length = irextract_param_check(x, "output length", out_length, 0., HUGE_VAL) / 1000.;

	// Process

	x->measure_mode = NOISE;
	coloured_noise_params(&x->noise_params, noise_mode, fade_in / 1000., fade_out / 1000., length / 1000., sample_rate, db_to_a(x->amp) / amp_comp);
	
	if (noise_mode != NOISE_MODE_WHITE)
	{
		coloured_noise_measure(&x->noise_params, (int) (length * sample_rate * 1000.), &max_pink, &max_brown);
		coloured_noise_reset(&x->noise_params);
	}
	if (noise_mode == NOISE_MODE_BROWN)
		amp_comp = max_brown;
	if (noise_mode == NOISE_MODE_PINK)
		amp_comp = max_pink;

	irextract_process(x, rec_buffer, num_channels, sample_rate);
}