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vdr/ac3dec/coeff.c
2001-08-09 11:41:39 +02:00

432 lines
11 KiB
C

/*
* coeff.c
*
* Copyright (C) Aaron Holtzman - May 1999
*
* This file is part of ac3dec, a free Dolby AC-3 stream decoder.
*
* ac3dec 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, or (at your option)
* any later version.
*
* ac3dec 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include "ac3.h"
#include "ac3_internal.h"
#include "bitstream.h"
#include "dither.h"
#include "coeff.h"
//
//Lookup tables of 0.15 two's complement quantization values
//
#define Q0 ((-2 << 15) / 3.0)
#define Q1 (0)
#define Q2 ((2 << 15) / 3.0)
static const float q_1_0[ 32 ] =
{
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
0,0,0,0,0
};
static const float q_1_1[ 32 ] =
{
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
Q0,Q0,Q0,Q1,Q1,Q1,Q2,Q2,Q2,
0,0,0,0,0
};
static const float q_1_2[ 32 ] =
{
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
Q0,Q1,Q2,Q0,Q1,Q2,Q0,Q1,Q2,
0,0,0,0,0
};
#undef Q0
#undef Q1
#undef Q2
#define Q0 ((-4 << 15) / 5.0)
#define Q1 ((-2 << 15) / 5.0)
#define Q2 (0)
#define Q3 ((2 << 15) / 5.0)
#define Q4 ((4 << 15) / 5.0)
static const float q_2_0[ 128 ] =
{
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,
Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,
Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,Q4,
0,0,0
};
static const float q_2_1[ 128 ] =
{
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q4,Q4,Q4,Q4,Q4,
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,Q0,Q0,Q0,Q0,Q0,
Q1,Q1,Q1,Q1,Q1,Q2,Q2,Q2,Q2,Q2,
Q3,Q3,Q3,Q3,Q3,Q4,Q4,Q4,Q4,Q4,
Q0,Q0,Q0,Q0,Q0,Q1,Q1,Q1,Q1,Q1,
Q2,Q2,Q2,Q2,Q2,Q3,Q3,Q3,Q3,Q3,
Q4,Q4,Q4,Q4,Q4,0,0,0
};
static const float q_2_2[ 128 ] =
{
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,Q0,Q1,Q2,Q3,Q4,
Q0,Q1,Q2,Q3,Q4,0,0,0
};
#undef Q0
#undef Q1
#undef Q2
#undef Q3
#undef Q4
static const float q_3[7] =
{
(-6 << 15)/7.0, (-4 << 15)/7.0, (-2 << 15)/7.0, 0.0,
( 2 << 15)/7.0, ( 4 << 15)/7.0, ( 6 << 15)/7.0
};
#define Q0 ((-10 << 15) / 11.0)
#define Q1 ((-8 << 15) / 11.0)
#define Q2 ((-6 << 15) / 11.0)
#define Q3 ((-4 << 15) / 11.0)
#define Q4 ((-2 << 15) / 11.0)
#define Q5 (0)
#define Q6 ((2 << 15) / 11.0)
#define Q7 ((4 << 15) / 11.0)
#define Q8 ((6 << 15) / 11.0)
#define Q9 ((8 << 15) / 11.0)
#define QA ((10 << 15) / 11.0)
static const float q_4_0[ 128 ] =
{
Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0, Q0,
Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1, Q1,
Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2, Q2,
Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3, Q3,
Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4, Q4,
Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5, Q5,
Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6, Q6,
Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7, Q7,
Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8, Q8,
Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9, Q9,
QA, QA, QA, QA, QA, QA, QA, QA, QA, QA, QA,
0, 0, 0, 0, 0, 0, 0
};
static const float q_4_1[ 128 ] =
{
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, QA,
0, 0, 0, 0, 0, 0, 0
};
#undef Q0
#undef Q1
#undef Q2
#undef Q3
#undef Q4
#undef Q5
#undef Q6
#undef Q7
#undef Q8
#undef Q9
#undef QA
static const float q_5[15] =
{
(-14 << 15)/15.0,(-12 << 15)/15.0,(-10 << 15)/15.0,
( -8 << 15)/15.0,( -6 << 15)/15.0,( -4 << 15)/15.0,
( -2 << 15)/15.0, 0.0 ,( 2 << 15)/15.0,
( 4 << 15)/15.0,( 6 << 15)/15.0,( 8 << 15)/15.0,
( 10 << 15)/15.0,( 12 << 15)/15.0,( 14 << 15)/15.0
};
//
// Scale factors for convert_to_float
//
static const uint32_t u32_scale_factors[25] =
{
0x38000000, //2 ^ -(0 + 15)
0x37800000, //2 ^ -(1 + 15)
0x37000000, //2 ^ -(2 + 15)
0x36800000, //2 ^ -(3 + 15)
0x36000000, //2 ^ -(4 + 15)
0x35800000, //2 ^ -(5 + 15)
0x35000000, //2 ^ -(6 + 15)
0x34800000, //2 ^ -(7 + 15)
0x34000000, //2 ^ -(8 + 15)
0x33800000, //2 ^ -(9 + 15)
0x33000000, //2 ^ -(10 + 15)
0x32800000, //2 ^ -(11 + 15)
0x32000000, //2 ^ -(12 + 15)
0x31800000, //2 ^ -(13 + 15)
0x31000000, //2 ^ -(14 + 15)
0x30800000, //2 ^ -(15 + 15)
0x30000000, //2 ^ -(16 + 15)
0x2f800000, //2 ^ -(17 + 15)
0x2f000000, //2 ^ -(18 + 15)
0x2e800000, //2 ^ -(19 + 15)
0x2e000000, //2 ^ -(20 + 15)
0x2d800000, //2 ^ -(21 + 15)
0x2d000000, //2 ^ -(22 + 15)
0x2c800000, //2 ^ -(23 + 15)
0x2c000000 //2 ^ -(24 + 15)
};
static float *scale_factor = (float*)u32_scale_factors;
//These store the persistent state of the packed mantissas
static float q_1[2];
static float q_2[2];
static float q_4[1];
static int32_t q_1_pointer;
static int32_t q_2_pointer;
static int32_t q_4_pointer;
static float __inline__
coeff_get_float(uint16_t bap, uint16_t dithflag, uint16_t exp);
//Conversion from bap to number of bits in the mantissas
//zeros account for cases 0,1,2,4 which are special cased
static uint16_t qnttztab[16] =
{
0, 0, 0, 3,
0, 4, 5, 6,
7, 8, 9, 10,
11, 12, 14, 16
};
static void coeff_reset(void);
static float coeff_get_float(uint16_t bap, uint16_t dithflag, uint16_t exp);
static void coeff_uncouple_ch(float samples[],bsi_t *bsi,audblk_t *audblk,uint32_t ch);
void coeff_unpack(bsi_t *bsi, audblk_t *audblk, stream_samples_t samples)
{
uint16_t i,j;
uint32_t done_cpl = 0;
coeff_reset();
for(i=0; i< bsi->nfchans; i++) {
for(j=0; j < audblk->endmant[i]; j++)
samples[i][j] = coeff_get_float(audblk->fbw_bap[i][j], audblk->dithflag[i], audblk->fbw_exp[i][j]);
if(audblk->cplinu && audblk->chincpl[i] && !(done_cpl)) {
// ncplmant is equal to 12 * ncplsubnd
// Don't dither coupling channel until channel
// separation so that interchannel noise is uncorrelated
for(j=audblk->cplstrtmant; j < audblk->cplendmant; j++)
audblk->cpl_flt[j] = coeff_get_float(audblk->cpl_bap[j],0, audblk->cpl_exp[j]);
done_cpl = 1;
}
}
//uncouple the channel if necessary
if(audblk->cplinu) {
for(i=0; i< bsi->nfchans; i++) {
if(audblk->chincpl[i])
coeff_uncouple_ch(samples[i],bsi,audblk,i);
}
}
if(bsi->lfeon) {
// There are always 7 mantissas for lfe, no dither for lfe
for(j=0; j < 7 ; j++)
samples[5][j] = coeff_get_float(audblk->lfe_bap[j], 0, audblk->lfe_exp[j]);
}
}
/**
* Fetch a float from the bitstream
**/
static float inline coeff_get_float (uint16_t bap, uint16_t dithflag, uint16_t exp)
{
uint16_t dummy = 0;
//If the bap is 0-5 then we have special cases to take care of
switch(bap) {
case 0:
if(dithflag)
return (dither_gen() * scale_factor[exp]);
return 0.0;
case 1:
if (q_1_pointer >= 0)
return(q_1[q_1_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (5)) > 26)
goto error;
q_1[1] = q_1_1[dummy];
q_1[0] = q_1_2[dummy];
q_1_pointer = 1;
return (q_1_0[dummy] * scale_factor[exp]);
case 2:
if(q_2_pointer >= 0)
return (q_2[q_2_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (7)) > 124)
goto error;
q_2[1] = q_2_1[dummy];
q_2[0] = q_2_2[dummy];
q_2_pointer = 1;
return (q_2_0[dummy] * scale_factor[exp]);
case 3:
if ((dummy = bitstream_get (3)) > 6)
goto error;
return (q_3[dummy] * scale_factor[exp]);
case 4:
if(q_4_pointer >= 0)
return (q_4[q_4_pointer--] * scale_factor[exp]);
if ((dummy = bitstream_get (7)) > 120)
goto error;
q_4[0] = q_4_1[dummy];
q_4_pointer = 0;
return (q_4_0[dummy] * scale_factor[exp]);
case 5:
if ((dummy = bitstream_get (4)) > 14)
goto error;
return (q_5[dummy] * scale_factor[exp]);
default:
dummy = bitstream_get(qnttztab[bap]);
dummy <<= 16 - qnttztab[bap];
return ((int16_t)dummy * scale_factor[exp]);
}
error:
#ifdef DEBUG
fprintf(stderr,"** Invalid mantissa - skipping frame **\n");
#endif
HANDLE_ERROR();
}
/**
* Reset the mantissa state
**/
static void coeff_reset(void)
{
q_1_pointer = q_2_pointer = q_4_pointer = -1;
}
/**
* Uncouple the coupling channel into a fbw channel
**/
static void coeff_uncouple_ch (float samples[],bsi_t *bsi,audblk_t *audblk,uint32_t ch)
{
uint32_t bnd = 0;
uint32_t sub_bnd = 0;
uint32_t i,j;
float cpl_coord = 1.0;
uint32_t cpl_exp_tmp;
uint32_t cpl_mant_tmp;
for (i=audblk->cplstrtmant;i<audblk->cplendmant;) {
if (!audblk->cplbndstrc[sub_bnd++]) {
cpl_exp_tmp = audblk->cplcoexp[ch][bnd] + 3 * audblk->mstrcplco[ch];
if (audblk->cplcoexp[ch][bnd] == 15)
cpl_mant_tmp = (audblk->cplcomant[ch][bnd]) << 11;
else
cpl_mant_tmp = ((0x10) | audblk->cplcomant[ch][bnd]) << 10;
cpl_coord = (cpl_mant_tmp * scale_factor[cpl_exp_tmp]) * 8.0f;
//Invert the phase for the right channel if necessary
if(bsi->acmod == 0x2 && audblk->phsflginu && ch == 1 && audblk->phsflg[bnd])
cpl_coord *= -1;
bnd++;
}
for(j=0;j < 12; j++) {
// Get new dither values for each channel if necessary,
// so the channels are uncorrelated
if(audblk->dithflag[ch] && !audblk->cpl_bap[i])
samples[i] = cpl_coord * (dither_gen() * scale_factor[audblk->cpl_exp[i]]);
else
samples[i] = cpl_coord * audblk->cpl_flt[i];
i++;
}
}
}