FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/cngdec.c
Date: 2022-07-04 19:11:22
Exec Total Coverage
Lines: 0 78 0.0%
Branches: 0 34 0.0%

Line Branch Exec Source
1 /*
2 * RFC 3389 comfort noise generator
3 * Copyright (c) 2012 Martin Storsjo
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
22 #include <math.h>
23
24 #include "libavutil/common.h"
25 #include "libavutil/ffmath.h"
26 #include "libavutil/intreadwrite.h"
27 #include "avcodec.h"
28 #include "celp_filters.h"
29 #include "codec_internal.h"
30 #include "internal.h"
31 #include "libavutil/lfg.h"
32
33 typedef struct CNGContext {
34 float *refl_coef, *target_refl_coef;
35 float *lpc_coef;
36 int order;
37 int energy, target_energy;
38 int inited;
39 float *filter_out;
40 float *excitation;
41 AVLFG lfg;
42 } CNGContext;
43
44 static av_cold int cng_decode_close(AVCodecContext *avctx)
45 {
46 CNGContext *p = avctx->priv_data;
47 av_freep(&p->refl_coef);
48 av_freep(&p->target_refl_coef);
49 av_freep(&p->lpc_coef);
50 av_freep(&p->filter_out);
51 av_freep(&p->excitation);
52 return 0;
53 }
54
55 static av_cold int cng_decode_init(AVCodecContext *avctx)
56 {
57 CNGContext *p = avctx->priv_data;
58
59 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
60 av_channel_layout_uninit(&avctx->ch_layout);
61 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
62 avctx->sample_rate = 8000;
63
64 p->order = 12;
65 avctx->frame_size = 640;
66 p->refl_coef = av_calloc(p->order, sizeof(*p->refl_coef));
67 p->target_refl_coef = av_calloc(p->order, sizeof(*p->target_refl_coef));
68 p->lpc_coef = av_calloc(p->order, sizeof(*p->lpc_coef));
69 p->filter_out = av_calloc(avctx->frame_size + p->order,
70 sizeof(*p->filter_out));
71 p->excitation = av_calloc(avctx->frame_size, sizeof(*p->excitation));
72 if (!p->refl_coef || !p->target_refl_coef || !p->lpc_coef ||
73 !p->filter_out || !p->excitation) {
74 return AVERROR(ENOMEM);
75 }
76
77 av_lfg_init(&p->lfg, 0);
78
79 return 0;
80 }
81
82 static void make_lpc_coefs(float *lpc, const float *refl, int order)
83 {
84 float buf[100];
85 float *next, *cur;
86 int m, i;
87 next = buf;
88 cur = lpc;
89 for (m = 0; m < order; m++) {
90 next[m] = refl[m];
91 for (i = 0; i < m; i++)
92 next[i] = cur[i] + refl[m] * cur[m - i - 1];
93 FFSWAP(float*, next, cur);
94 }
95 if (cur != lpc)
96 memcpy(lpc, cur, sizeof(*lpc) * order);
97 }
98
99 static void cng_decode_flush(AVCodecContext *avctx)
100 {
101 CNGContext *p = avctx->priv_data;
102 p->inited = 0;
103 }
104
105 static int cng_decode_frame(AVCodecContext *avctx, AVFrame *frame,
106 int *got_frame_ptr, AVPacket *avpkt)
107 {
108 CNGContext *p = avctx->priv_data;
109 int buf_size = avpkt->size;
110 int ret, i;
111 int16_t *buf_out;
112 float e = 1.0;
113 float scaling;
114
115 if (avpkt->size) {
116 int dbov = -avpkt->data[0];
117 p->target_energy = 1081109975 * ff_exp10(dbov / 10.0) * 0.75;
118 memset(p->target_refl_coef, 0, p->order * sizeof(*p->target_refl_coef));
119 for (i = 0; i < FFMIN(avpkt->size - 1, p->order); i++) {
120 p->target_refl_coef[i] = (avpkt->data[1 + i] - 127) / 128.0;
121 }
122 }
123
124 if (avctx->internal->skip_samples > 10 * avctx->frame_size) {
125 avctx->internal->skip_samples = 0;
126 return AVERROR_INVALIDDATA;
127 }
128
129 if (p->inited) {
130 p->energy = p->energy / 2 + p->target_energy / 2;
131 for (i = 0; i < p->order; i++)
132 p->refl_coef[i] = 0.6 *p->refl_coef[i] + 0.4 * p->target_refl_coef[i];
133 } else {
134 p->energy = p->target_energy;
135 memcpy(p->refl_coef, p->target_refl_coef, p->order * sizeof(*p->refl_coef));
136 p->inited = 1;
137 }
138 make_lpc_coefs(p->lpc_coef, p->refl_coef, p->order);
139
140 for (i = 0; i < p->order; i++)
141 e *= 1.0 - p->refl_coef[i]*p->refl_coef[i];
142
143 scaling = sqrt(e * p->energy / 1081109975);
144 for (i = 0; i < avctx->frame_size; i++) {
145 int r = (av_lfg_get(&p->lfg) & 0xffff) - 0x8000;
146 p->excitation[i] = scaling * r;
147 }
148 ff_celp_lp_synthesis_filterf(p->filter_out + p->order, p->lpc_coef,
149 p->excitation, avctx->frame_size, p->order);
150
151 frame->nb_samples = avctx->frame_size;
152 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
153 return ret;
154 buf_out = (int16_t *)frame->data[0];
155 for (i = 0; i < avctx->frame_size; i++)
156 buf_out[i] = av_clip_int16(p->filter_out[i + p->order]);
157 memcpy(p->filter_out, p->filter_out + avctx->frame_size,
158 p->order * sizeof(*p->filter_out));
159
160 *got_frame_ptr = 1;
161
162 return buf_size;
163 }
164
165 const FFCodec ff_comfortnoise_decoder = {
166 .p.name = "comfortnoise",
167 .p.long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"),
168 .p.type = AVMEDIA_TYPE_AUDIO,
169 .p.id = AV_CODEC_ID_COMFORT_NOISE,
170 .priv_data_size = sizeof(CNGContext),
171 .init = cng_decode_init,
172 FF_CODEC_DECODE_CB(cng_decode_frame),
173 .flush = cng_decode_flush,
174 .close = cng_decode_close,
175 .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
176 AV_SAMPLE_FMT_NONE },
177 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
178 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
179 FF_CODEC_CAP_INIT_CLEANUP,
180 };
181