lavc: fix support of unofficial pix_fmt extensions of jpeg
[ffmpeg.git] / libavcodec / acelp_pitch_delay.c
1 /*
2  * gain code, gain pitch and pitch delay decoding
3  *
4  * Copyright (c) 2008 Vladimir Voroshilov
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 #include "libavutil/mathematics.h"
24 #include "avcodec.h"
25 #include "dsputil.h"
26 #include "acelp_pitch_delay.h"
27 #include "celp_math.h"
28
29 int ff_acelp_decode_8bit_to_1st_delay3(int ac_index)
30 {
31     ac_index += 58;
32     if(ac_index > 254)
33         ac_index = 3 * ac_index - 510;
34     return ac_index;
35 }
36
37 int ff_acelp_decode_4bit_to_2nd_delay3(
38         int ac_index,
39         int pitch_delay_min)
40 {
41     if(ac_index < 4)
42         return 3 * (ac_index + pitch_delay_min);
43     else if(ac_index < 12)
44         return 3 * pitch_delay_min + ac_index + 6;
45     else
46         return 3 * (ac_index + pitch_delay_min) - 18;
47 }
48
49 int ff_acelp_decode_5_6_bit_to_2nd_delay3(
50         int ac_index,
51         int pitch_delay_min)
52 {
53         return 3 * pitch_delay_min + ac_index - 2;
54 }
55
56 int ff_acelp_decode_9bit_to_1st_delay6(int ac_index)
57 {
58     if(ac_index < 463)
59         return ac_index + 105;
60     else
61         return 6 * (ac_index - 368);
62 }
63 int ff_acelp_decode_6bit_to_2nd_delay6(
64         int ac_index,
65         int pitch_delay_min)
66 {
67     return 6 * pitch_delay_min + ac_index - 3;
68 }
69
70 void ff_acelp_update_past_gain(
71     int16_t* quant_energy,
72     int gain_corr_factor,
73     int log2_ma_pred_order,
74     int erasure)
75 {
76     int i;
77     int avg_gain=quant_energy[(1 << log2_ma_pred_order) - 1]; // (5.10)
78
79     for(i=(1 << log2_ma_pred_order) - 1; i>0; i--)
80     {
81         avg_gain       += quant_energy[i-1];
82         quant_energy[i] = quant_energy[i-1];
83     }
84
85     if(erasure)
86         quant_energy[0] = FFMAX(avg_gain >> log2_ma_pred_order, -10240) - 4096; // -10 and -4 in (5.10)
87     else
88         quant_energy[0] = (6165 * ((ff_log2(gain_corr_factor) >> 2) - (13 << 13))) >> 13;
89 }
90
91 int16_t ff_acelp_decode_gain_code(
92     DSPContext *dsp,
93     int gain_corr_factor,
94     const int16_t* fc_v,
95     int mr_energy,
96     const int16_t* quant_energy,
97     const int16_t* ma_prediction_coeff,
98     int subframe_size,
99     int ma_pred_order)
100 {
101     int i;
102
103     mr_energy <<= 10;
104
105     for(i=0; i<ma_pred_order; i++)
106         mr_energy += quant_energy[i] * ma_prediction_coeff[i];
107
108 #ifdef G729_BITEXACT
109     mr_energy += (((-6165LL * ff_log2(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size, 0))) >> 3) & ~0x3ff);
110
111     mr_energy = (5439 * (mr_energy >> 15)) >> 8;           // (0.15) = (0.15) * (7.23)
112
113     return bidir_sal(
114                ((ff_exp2(mr_energy & 0x7fff) + 16) >> 5) * (gain_corr_factor >> 1),
115                (mr_energy >> 15) - 25
116            );
117 #else
118     mr_energy = gain_corr_factor * exp(M_LN10 / (20 << 23) * mr_energy) /
119                 sqrt(dsp->scalarproduct_int16(fc_v, fc_v, subframe_size));
120     return mr_energy >> 12;
121 #endif
122 }
123
124 float ff_amr_set_fixed_gain(float fixed_gain_factor, float fixed_mean_energy,
125                             float *prediction_error, float energy_mean,
126                             const float *pred_table)
127 {
128     // Equations 66-69:
129     // ^g_c = ^gamma_gc * 100.05 (predicted dB + mean dB - dB of fixed vector)
130     // Note 10^(0.05 * -10log(average x2)) = 1/sqrt((average x2)).
131     float val = fixed_gain_factor *
132         exp2f(M_LOG2_10 * 0.05 *
133               (ff_dot_productf(pred_table, prediction_error, 4) +
134                energy_mean)) /
135         sqrtf(fixed_mean_energy);
136
137     // update quantified prediction error energy history
138     memmove(&prediction_error[0], &prediction_error[1],
139             3 * sizeof(prediction_error[0]));
140     prediction_error[3] = 20.0 * log10f(fixed_gain_factor);
141
142     return val;
143 }
144
145 void ff_decode_pitch_lag(int *lag_int, int *lag_frac, int pitch_index,
146                          const int prev_lag_int, const int subframe,
147                          int third_as_first, int resolution)
148 {
149     /* Note n * 10923 >> 15 is floor(x/3) for 0 <= n <= 32767 */
150     if (subframe == 0 || (subframe == 2 && third_as_first)) {
151
152         if (pitch_index < 197)
153             pitch_index += 59;
154         else
155             pitch_index = 3 * pitch_index - 335;
156
157     } else {
158         if (resolution == 4) {
159             int search_range_min = av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
160                                            PITCH_DELAY_MAX - 9);
161
162             // decoding with 4-bit resolution
163             if (pitch_index < 4) {
164                 // integer only precision for [search_range_min, search_range_min+3]
165                 pitch_index = 3 * (pitch_index + search_range_min) + 1;
166             } else if (pitch_index < 12) {
167                 // 1/3 fractional precision for [search_range_min+3 1/3, search_range_min+5 2/3]
168                 pitch_index += 3 * search_range_min + 7;
169             } else {
170                 // integer only precision for [search_range_min+6, search_range_min+9]
171                 pitch_index = 3 * (pitch_index + search_range_min - 6) + 1;
172             }
173         } else {
174             // decoding with 5 or 6 bit resolution, 1/3 fractional precision
175             pitch_index--;
176
177             if (resolution == 5) {
178                 pitch_index += 3 * av_clip(prev_lag_int - 10, PITCH_DELAY_MIN,
179                                            PITCH_DELAY_MAX - 19);
180             } else
181                 pitch_index += 3 * av_clip(prev_lag_int - 5, PITCH_DELAY_MIN,
182                                            PITCH_DELAY_MAX - 9);
183         }
184     }
185     *lag_int  = pitch_index * 10923 >> 15;
186     *lag_frac = pitch_index - 3 * *lag_int - 1;
187 }