xref: /third_party/ffmpeg/libavcodec/g723_1.h (revision cabdff1a)
1/*
2 * G.723.1 common header and data tables
3 * Copyright (c) 2006 Benjamin Larsson
4 * Copyright (c) 2010 Mohamed Naufal Basheer
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/**
24 * @file
25 * G.723.1 types, functions and data tables
26 */
27
28#ifndef AVCODEC_G723_1_H
29#define AVCODEC_G723_1_H
30
31#include <stdint.h>
32
33#include "libavutil/log.h"
34
35#define SUBFRAMES       4
36#define SUBFRAME_LEN    60
37#define FRAME_LEN       (SUBFRAME_LEN << 2)
38#define HALF_FRAME_LEN  (FRAME_LEN / 2)
39#define LPC_FRAME       (HALF_FRAME_LEN + SUBFRAME_LEN)
40#define LPC_ORDER       10
41#define LSP_BANDS       3
42#define LSP_CB_SIZE     256
43#define PITCH_MIN       18
44#define PITCH_MAX       (PITCH_MIN + 127)
45#define PITCH_ORDER     5
46#define GRID_SIZE       2
47#define PULSE_MAX       6
48#define GAIN_LEVELS     24
49#define COS_TBL_SIZE    512
50
51/**
52 * Bitexact implementation of 2ab scaled by 1/2^16.
53 *
54 * @param a 32 bit multiplicand
55 * @param b 16 bit multiplier
56 */
57#define MULL2(a, b) \
58        ((((a) >> 16) * (b) * 2) + (((a) & 0xffff) * (b) >> 15))
59
60/**
61 * G723.1 frame types
62 */
63enum FrameType {
64    ACTIVE_FRAME,        ///< Active speech
65    SID_FRAME,           ///< Silence Insertion Descriptor frame
66    UNTRANSMITTED_FRAME
67};
68
69/**
70 * G723.1 rate values
71 */
72enum Rate {
73    RATE_6300,
74    RATE_5300
75};
76
77/**
78 * G723.1 unpacked data subframe
79 */
80typedef struct G723_1_Subframe {
81    int ad_cb_lag;     ///< adaptive codebook lag
82    int ad_cb_gain;
83    int dirac_train;
84    int pulse_sign;
85    int grid_index;
86    int amp_index;
87    int pulse_pos;
88} G723_1_Subframe;
89
90/**
91 * Pitch postfilter parameters
92 */
93typedef struct PPFParam {
94    int     index;    ///< postfilter backward/forward lag
95    int16_t opt_gain; ///< optimal gain
96    int16_t sc_gain;  ///< scaling gain
97} PPFParam;
98
99/**
100 * Harmonic filter parameters
101 */
102typedef struct HFParam {
103    int index;
104    int gain;
105} HFParam;
106
107/**
108 * Optimized fixed codebook excitation parameters
109 */
110typedef struct FCBParam {
111    int min_err;
112    int amp_index;
113    int grid_index;
114    int dirac_train;
115    int pulse_pos[PULSE_MAX];
116    int pulse_sign[PULSE_MAX];
117} FCBParam;
118
119typedef struct G723_1_ChannelContext {
120    G723_1_Subframe subframe[4];
121    enum FrameType cur_frame_type;
122    enum FrameType past_frame_type;
123    enum Rate cur_rate;
124    uint8_t lsp_index[LSP_BANDS];
125    int pitch_lag[2];
126    int erased_frames;
127
128    int16_t prev_lsp[LPC_ORDER];
129    int16_t sid_lsp[LPC_ORDER];
130    int16_t prev_excitation[PITCH_MAX];
131    int16_t excitation[PITCH_MAX + FRAME_LEN + 4];
132    int16_t synth_mem[LPC_ORDER];
133    int16_t fir_mem[LPC_ORDER];
134    int     iir_mem[LPC_ORDER];
135
136    int random_seed;
137    int cng_random_seed;
138    int interp_index;
139    int interp_gain;
140    int sid_gain;
141    int cur_gain;
142    int reflection_coef;
143    int pf_gain;                 ///< formant postfilter
144                                 ///< gain scaling unit memory
145    int16_t audio[FRAME_LEN + LPC_ORDER + PITCH_MAX + 4];
146
147    /* encoder */
148    int16_t prev_data[HALF_FRAME_LEN];
149    int16_t prev_weight_sig[PITCH_MAX];
150
151    int16_t hpf_fir_mem;                   ///< highpass filter fir
152    int     hpf_iir_mem;                   ///< and iir memories
153    int16_t perf_fir_mem[LPC_ORDER];       ///< perceptual filter fir
154    int16_t perf_iir_mem[LPC_ORDER];       ///< and iir memories
155
156    int16_t harmonic_mem[PITCH_MAX];
157} G723_1_ChannelContext;
158
159typedef struct G723_1_Context {
160    AVClass *class;
161    int postfilter;
162
163    G723_1_ChannelContext ch[2];
164} G723_1_Context;
165
166
167/**
168 * Scale vector contents based on the largest of their absolutes.
169 */
170int ff_g723_1_scale_vector(int16_t *dst, const int16_t *vector, int length);
171
172/**
173 * Calculate the number of left-shifts required for normalizing the input.
174 *
175 * @param num   input number
176 * @param width width of the input, 16 bits(0) / 32 bits(1)
177 */
178int ff_g723_1_normalize_bits(int num, int width);
179
180int ff_g723_1_dot_product(const int16_t *a, const int16_t *b, int length);
181
182/**
183 * Get delayed contribution from the previous excitation vector.
184 */
185void ff_g723_1_get_residual(int16_t *residual, int16_t *prev_excitation,
186                            int lag);
187
188/**
189 * Generate a train of dirac functions with period as pitch lag.
190 */
191void ff_g723_1_gen_dirac_train(int16_t *buf, int pitch_lag);
192
193
194/**
195 * Generate adaptive codebook excitation.
196 */
197void ff_g723_1_gen_acb_excitation(int16_t *vector, int16_t *prev_excitation,
198                                  int pitch_lag, G723_1_Subframe *subfrm,
199                                  enum Rate cur_rate);
200/**
201 * Quantize LSP frequencies by interpolation and convert them to
202 * the corresponding LPC coefficients.
203 *
204 * @param lpc      buffer for LPC coefficients
205 * @param cur_lsp  the current LSP vector
206 * @param prev_lsp the previous LSP vector
207 */
208void ff_g723_1_lsp_interpolate(int16_t *lpc, int16_t *cur_lsp,
209                               int16_t *prev_lsp);
210
211/**
212 * Perform inverse quantization of LSP frequencies.
213 *
214 * @param cur_lsp    the current LSP vector
215 * @param prev_lsp   the previous LSP vector
216 * @param lsp_index  VQ indices
217 * @param bad_frame  bad frame flag
218 */
219void ff_g723_1_inverse_quant(int16_t *cur_lsp, int16_t *prev_lsp,
220                             uint8_t *lsp_index, int bad_frame);
221
222static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
223
224/**
225 * LSP DC component
226 */
227static const int16_t dc_lsp[LPC_ORDER] = {
228    0x0c3b,
229    0x1271,
230    0x1e0a,
231    0x2a36,
232    0x3630,
233    0x406f,
234    0x4d28,
235    0x56f4,
236    0x638c,
237    0x6c46
238};
239
240/* Cosine table scaled by 2^14 */
241extern const int16_t ff_g723_1_cos_tab[COS_TBL_SIZE + 1];
242#define G723_1_COS_TAB_FIRST_ELEMENT 16384
243
244/**
245 *  LSP VQ tables
246 */
247extern const int16_t ff_g723_1_lsp_band0[LSP_CB_SIZE][3];
248extern const int16_t ff_g723_1_lsp_band1[LSP_CB_SIZE][3];
249extern const int16_t ff_g723_1_lsp_band2[LSP_CB_SIZE][4];
250
251/**
252 * Used for the coding/decoding of the pulses positions
253 * for the MP-MLQ codebook
254 */
255extern const int32_t ff_g723_1_combinatorial_table[PULSE_MAX][SUBFRAME_LEN/GRID_SIZE];
256
257/**
258 * Number of non-zero pulses in the MP-MLQ excitation
259 */
260static const int8_t pulses[4] = {6, 5, 6, 5};
261
262extern const int16_t ff_g723_1_fixed_cb_gain[GAIN_LEVELS];
263
264extern const int16_t ff_g723_1_adaptive_cb_gain85 [ 85 * 20];
265extern const int16_t ff_g723_1_adaptive_cb_gain170[170 * 20];
266
267#endif /* AVCODEC_G723_1_H */
268