📄 downmix.c
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/*
* downmix.c
* Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
* Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
*
* This file is part of a52dec, a free ATSC A-52 stream decoder.
* See http://liba52.sourceforge.net/ for updates.
*
* a52dec 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.
*
* a52dec 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 02111-1307 USA
*/
#include "a52.h"
#include "a52_internal.h"
#define CONVERT(acmod,output) (((output) << 3) + (acmod))
int a52_downmix_init (int input, int flags, level_t * level,
level_t clev, level_t slev)
{
static uint8_t table[11][8] = {
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_STEREO,
A52_STEREO, A52_STEREO, A52_STEREO, A52_STEREO},
{A52_MONO, A52_MONO, A52_MONO, A52_MONO,
A52_MONO, A52_MONO, A52_MONO, A52_MONO},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_STEREO,
A52_STEREO, A52_STEREO, A52_STEREO, A52_STEREO},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_3F,
A52_STEREO, A52_3F, A52_STEREO, A52_3F},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_STEREO,
A52_2F1R, A52_2F1R, A52_2F1R, A52_2F1R},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_STEREO,
A52_2F1R, A52_3F1R, A52_2F1R, A52_3F1R},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_3F,
A52_2F2R, A52_2F2R, A52_2F2R, A52_2F2R},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_3F,
A52_2F2R, A52_3F2R, A52_2F2R, A52_3F2R},
{A52_CHANNEL1, A52_MONO, A52_MONO, A52_MONO,
A52_MONO, A52_MONO, A52_MONO, A52_MONO},
{A52_CHANNEL2, A52_MONO, A52_MONO, A52_MONO,
A52_MONO, A52_MONO, A52_MONO, A52_MONO},
{A52_CHANNEL, A52_DOLBY, A52_STEREO, A52_DOLBY,
A52_DOLBY, A52_DOLBY, A52_DOLBY, A52_DOLBY}
};
int output;
output = flags & A52_CHANNEL_MASK;
if (output > A52_DOLBY)
return -1;
output = table[output][input & 7];
if (output == A52_STEREO &&
(input == A52_DOLBY || (input == A52_3F && clev == LEVEL (LEVEL_3DB))))
output = A52_DOLBY;
if (flags & A52_ADJUST_LEVEL) {
level_t adjust;
switch (CONVERT (input & 7, output)) {
case CONVERT (A52_3F, A52_MONO):
adjust = DIV (LEVEL_3DB, LEVEL (1) + clev);
break;
case CONVERT (A52_STEREO, A52_MONO):
case CONVERT (A52_2F2R, A52_2F1R):
case CONVERT (A52_3F2R, A52_3F1R):
level_3db:
adjust = LEVEL (LEVEL_3DB);
break;
case CONVERT (A52_3F2R, A52_2F1R):
if (clev < LEVEL (LEVEL_PLUS3DB - 1))
goto level_3db;
/* break thru */
case CONVERT (A52_3F, A52_STEREO):
case CONVERT (A52_3F1R, A52_2F1R):
case CONVERT (A52_3F1R, A52_2F2R):
case CONVERT (A52_3F2R, A52_2F2R):
adjust = DIV (1, LEVEL (1) + clev);
break;
case CONVERT (A52_2F1R, A52_MONO):
adjust = DIV (LEVEL_PLUS3DB, LEVEL (2) + slev);
break;
case CONVERT (A52_2F1R, A52_STEREO):
case CONVERT (A52_3F1R, A52_3F):
adjust = DIV (1, LEVEL (1) + MUL_C (slev, LEVEL_3DB));
break;
case CONVERT (A52_3F1R, A52_MONO):
adjust = DIV (LEVEL_3DB, LEVEL (1) + clev + MUL_C (slev, 0.5));
break;
case CONVERT (A52_3F1R, A52_STEREO):
adjust = DIV (1, LEVEL (1) + clev + MUL_C (slev, LEVEL_3DB));
break;
case CONVERT (A52_2F2R, A52_MONO):
adjust = DIV (LEVEL_3DB, LEVEL (1) + slev);
break;
case CONVERT (A52_2F2R, A52_STEREO):
case CONVERT (A52_3F2R, A52_3F):
adjust = DIV (1, LEVEL (1) + slev);
break;
case CONVERT (A52_3F2R, A52_MONO):
adjust = DIV (LEVEL_3DB, LEVEL (1) + clev + slev);
break;
case CONVERT (A52_3F2R, A52_STEREO):
adjust = DIV (1, LEVEL (1) + clev + slev);
break;
case CONVERT (A52_MONO, A52_DOLBY):
adjust = LEVEL (LEVEL_PLUS3DB);
break;
case CONVERT (A52_3F, A52_DOLBY):
case CONVERT (A52_2F1R, A52_DOLBY):
adjust = LEVEL (1 / (1 + LEVEL_3DB));
break;
case CONVERT (A52_3F1R, A52_DOLBY):
case CONVERT (A52_2F2R, A52_DOLBY):
adjust = LEVEL (1 / (1 + 2 * LEVEL_3DB));
break;
case CONVERT (A52_3F2R, A52_DOLBY):
adjust = LEVEL (1 / (1 + 3 * LEVEL_3DB));
break;
default:
return output;
}
*level = MUL_L (*level, adjust);
}
return output;
}
int a52_downmix_coeff (level_t * coeff, int acmod, int output, level_t level,
level_t clev, level_t slev)
{
level_t level_3db;
level_3db = MUL_C (level, LEVEL_3DB);
switch (CONVERT (acmod, output & A52_CHANNEL_MASK)) {
case CONVERT (A52_CHANNEL, A52_CHANNEL):
case CONVERT (A52_MONO, A52_MONO):
case CONVERT (A52_STEREO, A52_STEREO):
case CONVERT (A52_3F, A52_3F):
case CONVERT (A52_2F1R, A52_2F1R):
case CONVERT (A52_3F1R, A52_3F1R):
case CONVERT (A52_2F2R, A52_2F2R):
case CONVERT (A52_3F2R, A52_3F2R):
case CONVERT (A52_STEREO, A52_DOLBY):
coeff[0] = coeff[1] = coeff[2] = coeff[3] = coeff[4] = level;
return 0;
case CONVERT (A52_CHANNEL, A52_MONO):
coeff[0] = coeff[1] = MUL_C (level, LEVEL_6DB);
return 3;
case CONVERT (A52_STEREO, A52_MONO):
coeff[0] = coeff[1] = level_3db;
return 3;
case CONVERT (A52_3F, A52_MONO):
coeff[0] = coeff[2] = level_3db;
coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
return 7;
case CONVERT (A52_2F1R, A52_MONO):
coeff[0] = coeff[1] = level_3db;
coeff[2] = MUL_L (level_3db, slev);
return 7;
case CONVERT (A52_2F2R, A52_MONO):
coeff[0] = coeff[1] = level_3db;
coeff[2] = coeff[3] = MUL_L (level_3db, slev);
return 15;
case CONVERT (A52_3F1R, A52_MONO):
coeff[0] = coeff[2] = level_3db;
coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
coeff[3] = MUL_L (level_3db, slev);
return 15;
case CONVERT (A52_3F2R, A52_MONO):
coeff[0] = coeff[2] = level_3db;
coeff[1] = MUL_C (MUL_L (level_3db, clev), LEVEL_PLUS6DB);
coeff[3] = coeff[4] = MUL_L (level_3db, slev);
return 31;
case CONVERT (A52_MONO, A52_DOLBY):
coeff[0] = level_3db;
return 0;
case CONVERT (A52_3F, A52_DOLBY):
coeff[0] = coeff[2] = coeff[3] = coeff[4] = level;
coeff[1] = level_3db;
return 7;
case CONVERT (A52_3F, A52_STEREO):
case CONVERT (A52_3F1R, A52_2F1R):
case CONVERT (A52_3F2R, A52_2F2R):
coeff[0] = coeff[2] = coeff[3] = coeff[4] = level;
coeff[1] = MUL_L (level, clev);
return 7;
case CONVERT (A52_2F1R, A52_DOLBY):
coeff[0] = coeff[1] = level;
coeff[2] = level_3db;
return 7;
case CONVERT (A52_2F1R, A52_STEREO):
coeff[0] = coeff[1] = level;
coeff[2] = MUL_L (level_3db, slev);
return 7;
case CONVERT (A52_3F1R, A52_DOLBY):
coeff[0] = coeff[2] = level;
coeff[1] = coeff[3] = level_3db;
return 15;
case CONVERT (A52_3F1R, A52_STEREO):
coeff[0] = coeff[2] = level;
coeff[1] = MUL_L (level, clev);
coeff[3] = MUL_L (level_3db, slev);
return 15;
case CONVERT (A52_2F2R, A52_DOLBY):
coeff[0] = coeff[1] = level;
coeff[2] = coeff[3] = level_3db;
return 15;
case CONVERT (A52_2F2R, A52_STEREO):
coeff[0] = coeff[1] = level;
coeff[2] = coeff[3] = MUL_L (level, slev);
return 15;
case CONVERT (A52_3F2R, A52_DOLBY):
coeff[0] = coeff[2] = level;
coeff[1] = coeff[3] = coeff[4] = level_3db;
return 31;
case CONVERT (A52_3F2R, A52_2F1R):
coeff[0] = coeff[2] = level;
coeff[1] = MUL_L (level, clev);
coeff[3] = coeff[4] = level_3db;
return 31;
case CONVERT (A52_3F2R, A52_STEREO):
coeff[0] = coeff[2] = level;
coeff[1] = MUL_L (level, clev);
coeff[3] = coeff[4] = MUL_L (level, slev);
return 31;
case CONVERT (A52_3F1R, A52_3F):
coeff[0] = coeff[1] = coeff[2] = level;
coeff[3] = MUL_L (level_3db, slev);
return 13;
case CONVERT (A52_3F2R, A52_3F):
coeff[0] = coeff[1] = coeff[2] = level;
coeff[3] = coeff[4] = MUL_L (level, slev);
return 29;
case CONVERT (A52_2F2R, A52_2F1R):
coeff[0] = coeff[1] = level;
coeff[2] = coeff[3] = level_3db;
return 12;
case CONVERT (A52_3F2R, A52_3F1R):
coeff[0] = coeff[1] = coeff[2] = level;
coeff[3] = coeff[4] = level_3db;
return 24;
case CONVERT (A52_2F1R, A52_2F2R):
coeff[0] = coeff[1] = level;
coeff[2] = level_3db;
return 0;
case CONVERT (A52_3F1R, A52_2F2R):
coeff[0] = coeff[2] = level;
coeff[1] = MUL_L (level, clev);
coeff[3] = level_3db;
return 7;
case CONVERT (A52_3F1R, A52_3F2R):
coeff[0] = coeff[1] = coeff[2] = level;
coeff[3] = level_3db;
return 0;
case CONVERT (A52_CHANNEL, A52_CHANNEL1):
coeff[0] = level;
coeff[1] = 0;
return 0;
case CONVERT (A52_CHANNEL, A52_CHANNEL2):
coeff[0] = 0;
coeff[1] = level;
return 0;
}
return -1; /* NOTREACHED */
}
static void mix2to1 (sample_t * dest, sample_t * src, sample_t bias)
{
int i;
for (i = 0; i < 256; i++)
dest[i] += BIAS (src[i]);
}
static void mix3to1 (sample_t * samples, sample_t bias)
{
int i;
for (i = 0; i < 256; i++)
samples[i] += BIAS (samples[i + 256] + samples[i + 512]);
}
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