Пример #1
0
void a52_imdct_512 (sample_t * data, sample_t * delay, sample_t bias)
{
    int i, k;
    sample_t t_r, t_i, a_r, a_i, b_r, b_i, w_1, w_2;
    const sample_t * window = a52_imdct_window;
    complex_t buf[128];
	
    for (i = 0; i < 128; i++) {
	k = fftorder[i];
	t_r = pre1[i].real;
	t_i = pre1[i].imag;

	buf[i].real = t_i * data[255-k] + t_r * data[k];
	buf[i].imag = t_r * data[255-k] - t_i * data[k];
    }

    ifft128 (buf);

    /* Post IFFT complex multiply plus IFFT complex conjugate*/
    /* Window and convert to real valued signal */
    for (i = 0; i < 64; i++) {
	/* y[n] = z[n] * (xcos1[n] + j * xsin1[n]) ; */
	t_r = post1[i].real;
	t_i = post1[i].imag;

	a_r = t_r * buf[i].real     + t_i * buf[i].imag;
	a_i = t_i * buf[i].real     - t_r * buf[i].imag;
	b_r = t_i * buf[127-i].real + t_r * buf[127-i].imag;
	b_i = t_r * buf[127-i].real - t_i * buf[127-i].imag;

	w_1 = window[2*i];
	w_2 = window[255-2*i];
	data[2*i]     = delay[2*i] * w_2 - a_r * w_1 + bias;
	data[255-2*i] = delay[2*i] * w_1 + a_r * w_2 + bias;
	delay[2*i] = a_i;

	w_1 = window[2*i+1];
	w_2 = window[254-2*i];
	data[2*i+1]   = delay[2*i+1] * w_2 + b_r * w_1 + bias;
	data[254-2*i] = delay[2*i+1] * w_1 - b_r * w_2 + bias;
	delay[2*i+1] = b_i;
    }
}
Пример #2
0
void a52_imdct_512 (sample_t * data, sample_t * delay, sample_t bias)
{
    int i, k;
    sample_t t_r, t_i, a_r, a_i, b_r, b_i, w_1, w_2;
    const sample_t * window = a52_imdct_window;
    complex_t buf[128];
	
    for (i = 0; i < 128; i++) {
	k = fftorder[i];
	t_r = pre1[i].real;
	t_i = pre1[i].imag;
	BUTTERFLY_0 (buf[i].real, buf[i].imag, t_r, t_i, data[k], data[255-k]);
    }

    ifft128 (buf);

    /* Post IFFT complex multiply plus IFFT complex conjugate*/
    /* Window and convert to real valued signal */
    for (i = 0; i < 64; i++) {
	/* y[n] = z[n] * (xcos1[n] + j * xsin1[n]) ; */
	t_r = post1[i].real;
	t_i = post1[i].imag;
	BUTTERFLY_0 (a_r, a_i, t_i, t_r, buf[i].imag, buf[i].real);
	BUTTERFLY_0 (b_r, b_i, t_r, t_i, buf[127-i].imag, buf[127-i].real);

	w_1 = window[2*i];
	w_2 = window[255-2*i];
	BUTTERFLY_B (data[255-2*i], data[2*i], w_2, w_1, a_r, delay[2*i]);
	delay[2*i] = a_i;

	w_1 = window[2*i+1];
	w_2 = window[254-2*i];
	BUTTERFLY_B (data[2*i+1], data[254-2*i], w_1, w_2, b_r, delay[2*i+1]);
	delay[2*i+1] = b_i;
    }
}