1/*
2 * G.729 decoder
3 * Copyright (c) 2008 Vladimir Voroshilov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21#include <stdlib.h>
22#include <inttypes.h>
23#include <limits.h>
24#include <stdio.h>
25#include <string.h>
26#include <math.h>
27#include <assert.h>
28
29#include "avcodec.h"
30#include "libavutil/avutil.h"
31#include "bitstream.h"
32
33#include "g729.h"
34#include "lsp.h"
35#include "celp_math.h"
36#include "acelp_filters.h"
37#include "acelp_pitch_delay.h"
38#include "acelp_vectors.h"
39#include "g729data.h"
40
41/**
42 * minimum quantized LSF value (3.2.4)
43 * 0.005 in Q13
44 */
45#define LSFQ_MIN                   40
46
47/**
48 * maximum quantized LSF value (3.2.4)
49 * 3.135 in Q13
50 */
51#define LSFQ_MAX                   25681
52
53/**
54 * minimum LSF distance (3.2.4)
55 * 0.0391 in Q13
56 */
57#define LSFQ_DIFF_MIN              321
58
59/**
60 * minimum gain pitch value (3.8, Equation 47)
61 * 0.2 in (1.14)
62 */
63#define SHARP_MIN                  3277
64
65/**
66 * maximum gain pitch value (3.8, Equation 47)
67 * (EE) This does not comply with the specification.
68 * Specification says about 0.8, which should be
69 * 13107 in (1.14), but reference C code uses
70 * 13017 (equals to 0.7945) instead of it.
71 */
72#define SHARP_MAX                  13017
73
74typedef struct
75{
76    int sample_rate;
77    uint8_t packed_frame_size;  ///< input frame size(in bytes)
78    uint8_t unpacked_frame_size;///< output frame size (in bytes)
79    uint8_t fc_indexes_bits;    ///< size (in bits) of fixed-codebook index entry
80
81    /// mr_energy = mean_energy + 10 * log10(2^26  * subframe_size) in (7.13)
82    int mr_energy;
83} G729_format_description;
84
85/**
86 * \brief pseudo random number generator
87 */
88static inline uint16_t g729_random(uint16_t value)
89{
90    return 31821 * value + 13849;
91}
92
93/**
94 * Get parity bit of bit 2..7
95 */
96static inline int g729_get_parity(uint8_t value)
97{
98   return (0x6996966996696996ULL >> (value >> 2)) & 1;
99}
100
101    if(avctx->channels != 1)
102    {
103        av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
104        return AVERROR_NOFMT;
105    }
106
107        ff_acelp_weighted_vector_sum(
108                fc + pitch_delay_int[i],
109                fc + pitch_delay_int[i],
110                fc,
111                1 << 14,
112                av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX),
113                0,
114                14,
115                ctx->subframe_size - pitch_delay_int[i]);
116
117        if(ctx->frame_erasure)
118        {
119            ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.9 (0.15)
120            ctx->gain_code  = (2007 * ctx->gain_code) >> 11;   // 0.98 in (0.11)
121
122            gain_corr_factor = 0;
123        }
124        else
125        {
126            ctx->gain_pitch  = cb_gain_1st_8k[parm->gc_1st_index[i]][0] +
127                               cb_gain_2nd_8k[parm->gc_2nd_index[i]][0];
128            gain_corr_factor = cb_gain_1st_8k[parm->gc_1st_index[i]][1] +
129                               cb_gain_2nd_8k[parm->gc_2nd_index[i]][1];
130
131        ff_acelp_weighted_vector_sum(
132                ctx->exc + i * ctx->subframe_size,
133                ctx->exc + i * ctx->subframe_size,
134                fc,
135                (!voicing && ctx->frame_erasure) ? 0 : ctx->gain_pitch,
136                ( voicing && ctx->frame_erasure) ? 0 : ctx->gain_code,
137                1<<13,
138                14,
139                ctx->subframe_size);
140
141    if (buf_size<packed_frame_size)
142    {
143        av_log(avctx, AV_LOG_ERROR, "Error processing packet: packet size too small\n");
144        return AVERROR(EIO);
145    }
146    if (*data_size<unpacked_frame_size)
147    {
148        av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
149        return AVERROR(EIO);
150    }
151
152AVCodec g729_decoder =
153{
154    "g729",
155    CODEC_TYPE_AUDIO,
156    CODEC_ID_G729,
157    sizeof(G729_Context),
158    ff_g729_decoder_init,
159    NULL,
160    NULL,
161    ff_g729_decode_frame,
162    .long_name = NULL_IF_CONFIG_SMALL("G.729"),
163};
164