-
Notifications
You must be signed in to change notification settings - Fork 10
/
acelp_pitch_delay.c
186 lines (164 loc) · 5.95 KB
/
acelp_pitch_delay.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
* 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 "dsputil.h"
#include "acelp_pitch_delay.h"
#include "celp_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(
DSPContext *dsp,
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(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 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(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 0));
return mr_energy >> 12;
#endif
}
float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
float *prediction_error, float energy_mean,
const float *pred_table)
{
// Equations 66-69:
// ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
// Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
float val = fixed_gain_factor *
exp2f(M_LOG2_10 * 0.05 *
(ff_dot_productf(pred_table, prediction_error, 4) +
energy_mean)) /
sqrtf(fixed_mean_energy);
// update quantified prediction error energy history
memmove(&prediction_error[0], &prediction_error[1],
3 * sizeof(prediction_error[0]));
prediction_error[3] = 20.0 * log10f(fixed_gain_factor);
return val;
}
void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index,
const int prev_lag_int, const int subframe,
int third_as_first, int resolution)
{
/* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */
if (subframe == 0 || (subframe == 2 && third_as_first)) {
if (pitch_index < 197)
pitch_index += 59;
else
pitch_index = 3 * pitch_index - 335;
} else {
if (resolution == 4) {
int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
PITCH_DELAY_MAX - 9);
// decoding with 4-bit resolution
if (pitch_index < 4) {
// integer only precision for [search_range_min, search_range_min+3]
pitch_index = 3 * (pitch_index + search_range_min) + 1;
} else if (pitch_index < 12) {
// 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3]
pitch_index += 3 * search_range_min + 7;
} else {
// integer only precision for [search_range_min+6, search_range_min+9]
pitch_index = 3 * (pitch_index + search_range_min - 6) + 1;
}
} else {
// decoding with 5 or 6 bit resolution, 1/3 fractional precision
pitch_index--;
if (resolution == 5) {
pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
PITCH_DELAY_MAX - 19);
} else
pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
PITCH_DELAY_MAX - 9);
}
}
*lag_int = pitch_index * 10923 >> 15;
*lag_frac = pitch_index - 3 * *lag_int - 1;
}