120 lines
3.3 KiB
C
120 lines
3.3 KiB
C
/*
|
|
* gain code, gain pitch and pitch delay decoding
|
|
*
|
|
* Copyright (c) 2008 Vladimir Voroshilov
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
#include "acelp_pitch_delay.h"
|
|
#include "acelp_math.h"
|
|
|
|
int ff_acelp_decode_8bit_to_1st_delay3(int ac_index)
|
|
{
|
|
ac_index += 58;
|
|
if(ac_index > 254)
|
|
ac_index = 3 * ac_index - 510;
|
|
return ac_index;
|
|
}
|
|
|
|
int ff_acelp_decode_4bit_to_2nd_delay3(
|
|
int ac_index,
|
|
int pitch_delay_min)
|
|
{
|
|
if(ac_index < 4)
|
|
return 3 * (ac_index + pitch_delay_min);
|
|
else if(ac_index < 12)
|
|
return 3 * pitch_delay_min + ac_index + 6;
|
|
else
|
|
return 3 * (ac_index + pitch_delay_min) - 18;
|
|
}
|
|
|
|
int ff_acelp_decode_5_6_bit_to_2nd_delay3(
|
|
int ac_index,
|
|
int pitch_delay_min)
|
|
{
|
|
return 3 * pitch_delay_min + ac_index - 2;
|
|
}
|
|
|
|
int ff_acelp_decode_9bit_to_1st_delay6(int ac_index)
|
|
{
|
|
if(ac_index < 463)
|
|
return ac_index + 105;
|
|
else
|
|
return 6 * (ac_index - 368);
|
|
}
|
|
int ff_acelp_decode_6bit_to_2nd_delay6(
|
|
int ac_index,
|
|
int pitch_delay_min)
|
|
{
|
|
return 6 * pitch_delay_min + ac_index - 3;
|
|
}
|
|
|
|
void ff_acelp_update_past_gain(
|
|
int16_t* quant_energy,
|
|
int gain_corr_factor,
|
|
int log2_ma_pred_order,
|
|
int erasure)
|
|
{
|
|
int i;
|
|
int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10)
|
|
|
|
for(i=(1 << log2_ma_pred_order) - 1; i>0; i--)
|
|
{
|
|
avg_gain += quant_energy[i-1];
|
|
quant_energy[i] = quant_energy[i-1];
|
|
}
|
|
|
|
if(erasure)
|
|
quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10)
|
|
else
|
|
quant_energy[0] = (6165 * ((ff_log2(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
|
|
}
|
|
|
|
int16_t ff_acelp_decode_gain_code(
|
|
int gain_corr_factor,
|
|
const int16_t* fc_v,
|
|
int mr_energy,
|
|
const int16_t* quant_energy,
|
|
const int16_t* ma_prediction_coeff,
|
|
int subframe_size,
|
|
int ma_pred_order)
|
|
{
|
|
int i;
|
|
|
|
mr_energy <<= 10;
|
|
|
|
for(i=0; i<ma_pred_order; i++)
|
|
mr_energy += quant_energy[i] * ma_prediction_coeff[i];
|
|
|
|
#ifdef G729_BITEXACT
|
|
mr_energy += (((-6165LL * ff_log2(sum_of_squares(fc_v, subframe_size, 0, 0))) >> 3) & ~0x3ff);
|
|
|
|
mr_energy = (5439 * (mr_energy >> 15)) >> 8; // (0.15) = (0.15) * (7.23)
|
|
|
|
return bidir_sal(
|
|
((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1),
|
|
(mr_energy >> 15) - 25
|
|
);
|
|
#else
|
|
mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) /
|
|
sqrt(sum_of_squares(fc_v, subframe_size, 0, 0));
|
|
return mr_energy >> 12;
|
|
#endif
|
|
}
|