* Fixed the ac3dec compilation under BeOS.

[vlc.git] / src / ac3_decoder / ac3_imdct.c

/*****************************************************************************
 * ac3_imdct.c: ac3 DCT
 *****************************************************************************
 * Copyright (C) 1999, 2000 VideoLAN
 * $Id: ac3_imdct.c,v 1.16 2001/04/26 11:23:16 sam Exp $
 *
 * Authors: Michel Kaempf <maxx@via.ecp.fr>
 *          Aaron Holtzman <aholtzma@engr.uvic.ca>
 *          Renaud Dartus <reno@videolan.org>
 *
 * 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 of the License, 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; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include "defs.h"

#include <math.h>
#include <stdio.h>

#include "config.h"
#include "common.h"
#include "threads.h"
#include "mtime.h"

#include "stream_control.h"
#include "input_ext-dec.h"

#include "ac3_decoder.h"
#include "ac3_internal.h"

#include "ac3_downmix.h"

#ifndef M_PI
#   define M_PI 3.14159265358979323846
#endif

void imdct_do_256(imdct_t * p_imdct, float x[],float y[], int id);
void imdct_do_512(imdct_t * p_imdct, float x[],float y[], int id);

/* 128 point bit-reverse LUT */
static const u8 bit_reverse_512[] = {
    0x00, 0x40, 0x20, 0x60, 0x10, 0x50, 0x30, 0x70,
    0x08, 0x48, 0x28, 0x68, 0x18, 0x58, 0x38, 0x78,
    0x04, 0x44, 0x24, 0x64, 0x14, 0x54, 0x34, 0x74,
    0x0c, 0x4c, 0x2c, 0x6c, 0x1c, 0x5c, 0x3c, 0x7c,
    0x02, 0x42, 0x22, 0x62, 0x12, 0x52, 0x32, 0x72,
    0x0a, 0x4a, 0x2a, 0x6a, 0x1a, 0x5a, 0x3a, 0x7a,
    0x06, 0x46, 0x26, 0x66, 0x16, 0x56, 0x36, 0x76,
    0x0e, 0x4e, 0x2e, 0x6e, 0x1e, 0x5e, 0x3e, 0x7e,
    0x01, 0x41, 0x21, 0x61, 0x11, 0x51, 0x31, 0x71,
    0x09, 0x49, 0x29, 0x69, 0x19, 0x59, 0x39, 0x79,
    0x05, 0x45, 0x25, 0x65, 0x15, 0x55, 0x35, 0x75,
    0x0d, 0x4d, 0x2d, 0x6d, 0x1d, 0x5d, 0x3d, 0x7d,
    0x03, 0x43, 0x23, 0x63, 0x13, 0x53, 0x33, 0x73,
    0x0b, 0x4b, 0x2b, 0x6b, 0x1b, 0x5b, 0x3b, 0x7b,
    0x07, 0x47, 0x27, 0x67, 0x17, 0x57, 0x37, 0x77,
    0x0f, 0x4f, 0x2f, 0x6f, 0x1f, 0x5f, 0x3f, 0x7f};

static const u8 bit_reverse_256[] = {
    0x00, 0x20, 0x10, 0x30, 0x08, 0x28, 0x18, 0x38,
    0x04, 0x24, 0x14, 0x34, 0x0c, 0x2c, 0x1c, 0x3c,
    0x02, 0x22, 0x12, 0x32, 0x0a, 0x2a, 0x1a, 0x3a,
    0x06, 0x26, 0x16, 0x36, 0x0e, 0x2e, 0x1e, 0x3e,
    0x01, 0x21, 0x11, 0x31, 0x09, 0x29, 0x19, 0x39,
    0x05, 0x25, 0x15, 0x35, 0x0d, 0x2d, 0x1d, 0x3d,
    0x03, 0x23, 0x13, 0x33, 0x0b, 0x2b, 0x1b, 0x3b,
    0x07, 0x27, 0x17, 0x37, 0x0f, 0x2f, 0x1f, 0x3f};

/* Windowing function for Modified DCT - Thank you acroread */
static float window[] = {
    0.00014, 0.00024, 0.00037, 0.00051, 0.00067, 0.00086, 0.00107, 0.00130,
    0.00157, 0.00187, 0.00220, 0.00256, 0.00297, 0.00341, 0.00390, 0.00443,
    0.00501, 0.00564, 0.00632, 0.00706, 0.00785, 0.00871, 0.00962, 0.01061,
    0.01166, 0.01279, 0.01399, 0.01526, 0.01662, 0.01806, 0.01959, 0.02121,
    0.02292, 0.02472, 0.02662, 0.02863, 0.03073, 0.03294, 0.03527, 0.03770,
    0.04025, 0.04292, 0.04571, 0.04862, 0.05165, 0.05481, 0.05810, 0.06153,
    0.06508, 0.06878, 0.07261, 0.07658, 0.08069, 0.08495, 0.08935, 0.09389,
    0.09859, 0.10343, 0.10842, 0.11356, 0.11885, 0.12429, 0.12988, 0.13563,
    0.14152, 0.14757, 0.15376, 0.16011, 0.16661, 0.17325, 0.18005, 0.18699,
    0.19407, 0.20130, 0.20867, 0.21618, 0.22382, 0.23161, 0.23952, 0.24757,
    0.25574, 0.26404, 0.27246, 0.28100, 0.28965, 0.29841, 0.30729, 0.31626,
    0.32533, 0.33450, 0.34376, 0.35311, 0.36253, 0.37204, 0.38161, 0.39126,
    0.40096, 0.41072, 0.42054, 0.43040, 0.44030, 0.45023, 0.46020, 0.47019,
    0.48020, 0.49022, 0.50025, 0.51028, 0.52031, 0.53033, 0.54033, 0.55031,
    0.56026, 0.57019, 0.58007, 0.58991, 0.59970, 0.60944, 0.61912, 0.62873,
    0.63827, 0.64774, 0.65713, 0.66643, 0.67564, 0.68476, 0.69377, 0.70269,
    0.71150, 0.72019, 0.72877, 0.73723, 0.74557, 0.75378, 0.76186, 0.76981,
    0.77762, 0.78530, 0.79283, 0.80022, 0.80747, 0.81457, 0.82151, 0.82831,
    0.83496, 0.84145, 0.84779, 0.85398, 0.86001, 0.86588, 0.87160, 0.87716,
    0.88257, 0.88782, 0.89291, 0.89785, 0.90264, 0.90728, 0.91176, 0.91610,
    0.92028, 0.92432, 0.92822, 0.93197, 0.93558, 0.93906, 0.94240, 0.94560,
    0.94867, 0.95162, 0.95444, 0.95713, 0.95971, 0.96217, 0.96451, 0.96674,
    0.96887, 0.97089, 0.97281, 0.97463, 0.97635, 0.97799, 0.97953, 0.98099,
    0.98236, 0.98366, 0.98488, 0.98602, 0.98710, 0.98811, 0.98905, 0.98994,
    0.99076, 0.99153, 0.99225, 0.99291, 0.99353, 0.99411, 0.99464, 0.99513,
    0.99558, 0.99600, 0.99639, 0.99674, 0.99706, 0.99736, 0.99763, 0.99788,
    0.99811, 0.99831, 0.99850, 0.99867, 0.99882, 0.99895, 0.99908, 0.99919,
    0.99929, 0.99938, 0.99946, 0.99953, 0.99959, 0.99965, 0.99969, 0.99974,
    0.99978, 0.99981, 0.99984, 0.99986, 0.99988, 0.99990, 0.99992, 0.99993,
    0.99994, 0.99995, 0.99996, 0.99997, 0.99998, 0.99998, 0.99998, 0.99999,
    0.99999, 0.99999, 0.99999, 1.00000, 1.00000, 1.00000, 1.00000, 1.00000,
    1.00000, 1.00000, 1.00000, 1.00000, 1.00000, 1.00000, 1.00000, 1.00000 };

static __inline__ void swap_cmplx(complex_t *a, complex_t *b)
{
    complex_t tmp;

    tmp = *a;
    *a = *b;
    *b = tmp;
}

static __inline__ complex_t cmplx_mult(complex_t a, complex_t b)
{
    complex_t ret;

    ret.real = a.real * b.real - a.imag * b.imag;
    ret.imag = a.real * b.imag + a.imag * b.real;

    return ret;
}

void imdct_init(imdct_t * p_imdct)
{
    int i,k;
    complex_t angle_step;
    complex_t current_angle;
    
    /* Twiddle factors to turn IFFT into IMDCT */
    for (i=0; i < N/4; i++) {
        p_imdct->xcos1[i] = -cos(2 * M_PI * (8*i+1)/(8*N)) ;
        p_imdct->xsin1[i] = -sin(2 * M_PI * (8*i+1)/(8*N)) ;
    }

    /* More twiddle factors to turn IFFT into IMDCT */
    for (i=0; i < N/8; i++) {
        p_imdct->xcos2[i] = -cos(2 * M_PI * (8*i+1)/(4*N)) ;
        p_imdct->xsin2[i] = -sin(2 * M_PI * (8*i+1)/(4*N)) ;
    }

    /* Canonical twiddle factors for FFT */
    p_imdct->w[0] = p_imdct->w_1;
    p_imdct->w[1] = p_imdct->w_2;
    p_imdct->w[2] = p_imdct->w_4;
    p_imdct->w[3] = p_imdct->w_8;
    p_imdct->w[4] = p_imdct->w_16;
    p_imdct->w[5] = p_imdct->w_32;
    p_imdct->w[6] = p_imdct->w_64;

    for (i = 0; i < 7; i++) {
        angle_step.real = cos(-2.0f * M_PI / (1 << (i+1)));
        angle_step.imag = sin(-2.0f * M_PI / (1 << (i+1)));

        current_angle.real = 1.0f;
        current_angle.imag = 0.0f;

        for (k = 0; k < 1 << i; k++) {
            p_imdct->w[i][k] = current_angle;
            current_angle = cmplx_mult(current_angle,angle_step);
        }
    }
}

void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
{
    int i, i_stream_done;
    int doable = 0;
    void (*do_imdct)(imdct_t * p_imdct, float x[],float y[], int id);
    
    /* Test if dm in frequency is doable */
    if ( !(doable = p_ac3dec->audblk.blksw[0]) )
        do_imdct = imdct_do_512;
    else
        do_imdct = imdct_do_256;

    /* Downmix in the frequency domain if all the channes use the same imdct */
    for (i=0; i < p_ac3dec->bsi.nfchans; i++)
    {
        if ( doable != p_ac3dec->audblk.blksw[i] )
        {
            do_imdct = NULL;
            break;
        }
    }
    
    if (do_imdct)
    {
        i_stream_done = downmix(p_ac3dec, p_ac3dec->coeffs.fbw[0], buffer);
        do_imdct(&p_ac3dec->imdct,p_ac3dec->coeffs.fbw[0],p_ac3dec->samples.channel[0], 0);
        do_imdct(&p_ac3dec->imdct, p_ac3dec->coeffs.fbw[1],p_ac3dec->samples.channel[1], 1);
    } else {
        for (i=0; i<p_ac3dec->bsi.nfchans;i++) {
            if (p_ac3dec->audblk.blksw[i])
                imdct_do_256(&p_ac3dec->imdct, p_ac3dec->coeffs.fbw[i],p_ac3dec->samples.channel[i], i);
            else
                imdct_do_512(&p_ac3dec->imdct, p_ac3dec->coeffs.fbw[i],p_ac3dec->samples.channel[i], i);
        }
        i_stream_done = downmix(p_ac3dec, p_ac3dec->samples.channel[0], buffer);
    }

    if ( !i_stream_done ) /* We have to stream sample */
    {
        stream_sample_2ch_to_s16_c(buffer, p_ac3dec->samples.channel[0],
                p_ac3dec->samples.channel[1]);
    } else {
        stream_sample_1ch_to_s16_c(buffer, p_ac3dec->samples.channel[0]);
    }

    /* XXX?? We don't bother with the IMDCT for the LFE as it's currently
     * unused. */
    //if (bsi->lfeon)
    //    imdct_do_512(coeffs->lfe,samples->channel[5],delay[5]);
}

void imdct_do_512(imdct_t * p_imdct, float x[], float y[], int id)
{
    int i,k;
    int p,q;
    int m;
    int two_m;
    int two_m_plus_one;

    float tmp_a_i;
    float tmp_a_r;
    float tmp_b_i;
    float tmp_b_r;


    float *y_ptr;
    float *delay_ptr;
    float *window_ptr;

    /* Pre IFFT complex multiply plus IFFT cmplx conjugate */
    for (i=0; i < N/4; i++) {
        /* z[i] = (X[N/2-2*i-1] + j * X[2*i]) * (xcos1[i] + j * xsin1[i]) ; */
        p_imdct->buf[i].real =  (x[N/2-2*i-1] * p_imdct->xcos1[i])  - (x[2*i]       * p_imdct->xsin1[i]);
        p_imdct->buf[i].imag = -((x[2*i]       * p_imdct->xcos1[i])  + (x[N/2-2*i-1] * p_imdct->xsin1[i]));
    }

    /* Bit reversed shuffling */
    for (i=0; i<N/4; i++) {
        k = bit_reverse_512[i];
        if (k < i)
            swap_cmplx(&p_imdct->buf[i],&p_imdct->buf[k]);
    }

    /* FFT Merge */
    for (m=0; m < 7; m++) {
        two_m = (1 << m);
        two_m_plus_one = (1 << (m+1));

        for (k = 0; k < two_m; k++) {
            for (i = 0; i < 128; i += two_m_plus_one) {
                p = k + i;
                q = p + two_m;
                tmp_a_r = p_imdct->buf[p].real;
                tmp_a_i = p_imdct->buf[p].imag;
                tmp_b_r = p_imdct->buf[q].real * p_imdct->w[m][k].real - p_imdct->buf[q].imag * p_imdct->w[m][k].imag;
                tmp_b_i = p_imdct->buf[q].imag * p_imdct->w[m][k].real + p_imdct->buf[q].real * p_imdct->w[m][k].imag;
                p_imdct->buf[p].real = tmp_a_r + tmp_b_r;
                p_imdct->buf[p].imag =  tmp_a_i + tmp_b_i;
                p_imdct->buf[q].real = tmp_a_r - tmp_b_r;
                p_imdct->buf[q].imag =  tmp_a_i - tmp_b_i;
            }
        }
    }

    /* Post IFFT complex multiply  plus IFFT complex conjugate*/
    for (i=0; i < N/4; i++) {
        /* y[n] = z[n] * (xcos1[n] + j * xsin1[n]) ; */
        tmp_a_r =   p_imdct->buf[i].real;
        tmp_a_i = - p_imdct->buf[i].imag;
        p_imdct->buf[i].real =(tmp_a_r * p_imdct->xcos1[i])  - (tmp_a_i  * p_imdct->xsin1[i]);
        p_imdct->buf[i].imag =(tmp_a_r * p_imdct->xsin1[i])  + (tmp_a_i  * p_imdct->xcos1[i]);
    }

    y_ptr = y;
    delay_ptr = p_imdct->delay[id];
    window_ptr = window;
    /* Window and convert to real valued signal */
    for (i=0; i<N/8; i++) {
        *y_ptr++   = 2.0f * (-p_imdct->buf[N/8+i].imag   * *window_ptr++ + *delay_ptr++);
        *y_ptr++   = 2.0f * (p_imdct->buf[N/8-i-1].real * *window_ptr++ + *delay_ptr++);
    }

    for (i=0; i<N/8; i++) {
        *y_ptr++  = 2.0f * (-p_imdct->buf[i].real       * *window_ptr++ + *delay_ptr++);
        *y_ptr++  = 2.0f * (p_imdct->buf[N/4-i-1].imag * *window_ptr++ + *delay_ptr++);
    }

    /* The trailing edge of the window goes into the delay line */
    delay_ptr = p_imdct->delay[id];

    for (i=0; i<N/8; i++) {
        *delay_ptr++  = -p_imdct->buf[N/8+i].real   * *--window_ptr;
        *delay_ptr++  =  p_imdct->buf[N/8-i-1].imag * *--window_ptr;
    }

    for (i=0; i<N/8; i++) {
        *delay_ptr++  =  p_imdct->buf[i].imag       * *--window_ptr;
        *delay_ptr++  = -p_imdct->buf[N/4-i-1].real * *--window_ptr;
    }
}

void imdct_do_256(imdct_t * p_imdct,float x[],float y[], int id)
{
    int i,k;
    int p,q;
    int m;
    int two_m;
    int two_m_plus_one;

    float tmp_a_i;
    float tmp_a_r;
    float tmp_b_i;
    float tmp_b_r;

    complex_t *buf_1, *buf_2;

    buf_1 = &p_imdct->buf[0];
    buf_2 = &p_imdct->buf[64];

    /* Pre IFFT complex multiply plus IFFT cmplx conjugate */
    for (k=0; k<N/8; k++) {
        /* X1[k] = X[2*k]  */
        /* X2[k] = X[2*k+1]     */

        p = 2 * (N/4-2*k-1);
        q = 2 * (2 * k);

       /* Z1[k] = (X1[N/4-2*k-1] + j * X1[2*k]) * (xcos2[k] + j * xsin2[k]); */
        buf_1[k].real =    x[p] * p_imdct->xcos2[k] - x[q] * p_imdct->xsin2[k];
        buf_1[k].imag = - (x[q] * p_imdct->xcos2[k] + x[p] * p_imdct->xsin2[k]);
       /* Z2[k] = (X2[N/4-2*k-1] + j * X2[2*k]) * (xcos2[k] + j * xsin2[k]); */
        buf_2[k].real =    x[p + 1] * p_imdct->xcos2[k] - x[q + 1] * p_imdct->xsin2[k];
        buf_2[k].imag = - (x[q + 1] * p_imdct->xcos2[k] + x[p + 1] * p_imdct->xsin2[k]);
    }

    /* IFFT Bit reversed shuffling */
    for (i=0; i<N/8; i++) {
        k = bit_reverse_256[i];
        if (k < i) {
            swap_cmplx(&buf_1[i],&buf_1[k]);
            swap_cmplx(&buf_2[i],&buf_2[k]);
        }
    }

    /* FFT Merge */
    for (m=0; m < 6; m++) {
        two_m = (1 << m);
        two_m_plus_one = (1 << (m+1));

        for (k = 0; k < two_m; k++) {
            for (i = 0; i < 64; i += two_m_plus_one) {
                p = k + i;
                q = p + two_m;
                /* Do block 1 */
                tmp_a_r = buf_1[p].real;
                tmp_a_i = buf_1[p].imag;
                tmp_b_r = buf_1[q].real * p_imdct->w[m][k].real - buf_1[q].imag * p_imdct->w[m][k].imag;
                tmp_b_i = buf_1[q].imag * p_imdct->w[m][k].real + buf_1[q].real * p_imdct->w[m][k].imag;
                buf_1[p].real = tmp_a_r + tmp_b_r;
                buf_1[p].imag =  tmp_a_i + tmp_b_i;
                buf_1[q].real = tmp_a_r - tmp_b_r;
                buf_1[q].imag =  tmp_a_i - tmp_b_i;

                /* Do block 2 */
                tmp_a_r = buf_2[p].real;
                tmp_a_i = buf_2[p].imag;
                tmp_b_r = buf_2[q].real * p_imdct->w[m][k].real - buf_2[q].imag * p_imdct->w[m][k].imag;
                tmp_b_i = buf_2[q].imag * p_imdct->w[m][k].real + buf_2[q].real * p_imdct->w[m][k].imag;
                buf_2[p].real = tmp_a_r + tmp_b_r;
                buf_2[p].imag =  tmp_a_i + tmp_b_i;
                buf_2[q].real = tmp_a_r - tmp_b_r;
                buf_2[q].imag =  tmp_a_i - tmp_b_i;
            }
        }
    }

    /* Post IFFT complex multiply */
    for (i=0; i < N/8; i++) {
        /* y1[n] = z1[n] * (xcos2[n] + j * xs in2[n]) ; */
        tmp_a_r =   buf_1[i].real;
        tmp_a_i = - buf_1[i].imag;
        buf_1[i].real =(tmp_a_r * p_imdct->xcos2[i])  - (tmp_a_i  * p_imdct->xsin2[i]);
        buf_1[i].imag =(tmp_a_r * p_imdct->xsin2[i])  + (tmp_a_i  * p_imdct->xcos2[i]);
        /* y2[n] = z2[n] * (xcos2[n] + j * xsin2[n]) ; */
        tmp_a_r =   buf_2[i].real;
        tmp_a_i = - buf_2[i].imag;
        buf_2[i].real =(tmp_a_r * p_imdct->xcos2[i])  - (tmp_a_i  * p_imdct->xsin2[i]);
        buf_2[i].imag =(tmp_a_r * p_imdct->xsin2[i])  + (tmp_a_i  * p_imdct->xcos2[i]);
    }

    /* Window and convert to real valued signal */
    for (i=0; i<N/8; i++) {
        y[2*i]         = -buf_1[i].imag       * window[2*i];
        y[2*i+1]       =  buf_1[N/8-i-1].real * window[2*i+1];
        y[N/4+2*i]     = -buf_1[i].real       * window[N/4+2*i];
        y[N/4+2*i+1]   =  buf_1[N/8-i-1].imag * window[N/4+2*i+1];
        y[N/2+2*i]     = -buf_2[i].real       * window[N/2-2*i-1];
        y[N/2+2*i+1]   =  buf_2[N/8-i-1].imag * window[N/2-2*i-2];
        y[3*N/4+2*i]   =  buf_2[i].imag       * window[N/4-2*i-1];
        y[3*N/4+2*i+1] = -buf_2[N/8-i-1].real * window[N/4-2*i-2];
    }

    /* Overlap and add */
    for (i=0; i<N/2; i++) {
        y[i] = 2 * (y[i] + p_imdct->delay[id][i]);
        p_imdct->delay[id][i] = y[N/2+i];
    }
}