FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/g722dec.c
Date: 2025-08-19 23:55:23
Exec Total Coverage
Lines: 40 43 93.0%
Functions: 2 2 100.0%
Branches: 7 10 70.0%

Line Branch Exec Source
1 /*
2 * Copyright (c) CMU 1993 Computer Science, Speech Group
3 * Chengxiang Lu and Alex Hauptmann
4 * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
5 * Copyright (c) 2009 Kenan Gillet
6 * Copyright (c) 2010 Martin Storsjo
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 /**
26 * @file
27 * G.722 ADPCM audio decoder
28 *
29 * This G.722 decoder is a bit-exact implementation of the ITU G.722
30 * specification for all three specified bitrates - 64000bps, 56000bps
31 * and 48000bps. It passes the ITU tests.
32 *
33 * @note For the 56000bps and 48000bps bitrates, the lowest 1 or 2 bits
34 * respectively of each byte are ignored.
35 */
36
37 #include "libavutil/channel_layout.h"
38 #include "libavutil/opt.h"
39 #include "avcodec.h"
40 #include "codec_internal.h"
41 #include "decode.h"
42 #include "get_bits.h"
43 #include "g722.h"
44
45 #define OFFSET(x) offsetof(G722Context, x)
46 #define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
47 static const AVOption options[] = {
48 { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_INT, { .i64 = 8 }, 6, 8, AD },
49 { NULL }
50 };
51
52 static const AVClass g722_decoder_class = {
53 .class_name = "g722 decoder",
54 .item_name = av_default_item_name,
55 .option = options,
56 .version = LIBAVUTIL_VERSION_INT,
57 };
58
59 4 static av_cold int g722_decode_init(AVCodecContext * avctx)
60 {
61 4 G722Context *c = avctx->priv_data;
62
63 4 av_channel_layout_uninit(&avctx->ch_layout);
64 4 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
65 4 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
66
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4 if (!avctx->sample_rate)
67 avctx->sample_rate = 16000;
68
69 4 c->band[0].scale_factor = 8;
70 4 c->band[1].scale_factor = 2;
71 4 c->prev_samples_pos = 22;
72
73 4 ff_g722dsp_init(&c->dsp);
74
75 4 return 0;
76 }
77
78 static const int16_t low_inv_quant5[32] = {
79 -35, -35, -2919, -2195, -1765, -1458, -1219, -1023,
80 -858, -714, -587, -473, -370, -276, -190, -110,
81 2919, 2195, 1765, 1458, 1219, 1023, 858, 714,
82 587, 473, 370, 276, 190, 110, 35, -35
83 };
84
85 static const int16_t * const low_inv_quants[3] = { ff_g722_low_inv_quant6,
86 low_inv_quant5,
87 ff_g722_low_inv_quant4 };
88
89 263 static int g722_decode_frame(AVCodecContext *avctx, AVFrame *frame,
90 int *got_frame_ptr, AVPacket *avpkt)
91 {
92 263 G722Context *c = avctx->priv_data;
93 int16_t *out_buf;
94 int j, ret;
95 263 const int skip = 8 - c->bits_per_codeword;
96 263 const int16_t *quantizer_table = low_inv_quants[skip];
97 GetBitContext gb;
98
99 /* get output buffer */
100 263 frame->nb_samples = avpkt->size * 2;
101
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263 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
102 return ret;
103 263 out_buf = (int16_t *)frame->data[0];
104
105 263 ret = init_get_bits8(&gb, avpkt->data, avpkt->size);
106
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263 if (ret < 0)
107 return ret;
108
109
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220125 for (j = 0; j < avpkt->size; j++) {
110 int ilow, ihigh, rlow, rhigh, dhigh;
111 int xout[2];
112
113 219862 ihigh = get_bits(&gb, 2);
114 219862 ilow = get_bits(&gb, 6 - skip);
115 219862 skip_bits(&gb, skip);
116
117 219862 rlow = av_clip_intp2((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
118 219862 + c->band[0].s_predictor, 14);
119
120 219862 ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip));
121
122 219862 dhigh = c->band[1].scale_factor * ff_g722_high_inv_quant[ihigh] >> 10;
123 219862 rhigh = av_clip_intp2(dhigh + c->band[1].s_predictor, 14);
124
125 219862 ff_g722_update_high_predictor(&c->band[1], dhigh, ihigh);
126
127 219862 c->prev_samples[c->prev_samples_pos++] = rlow + rhigh;
128 219862 c->prev_samples[c->prev_samples_pos++] = rlow - rhigh;
129 219862 c->dsp.apply_qmf(c->prev_samples + c->prev_samples_pos - 24, xout);
130 219862 *out_buf++ = av_clip_int16(xout[0] >> 11);
131 219862 *out_buf++ = av_clip_int16(xout[1] >> 11);
132
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219862 if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) {
133 437 memmove(c->prev_samples, c->prev_samples + c->prev_samples_pos - 22,
134 22 * sizeof(c->prev_samples[0]));
135 437 c->prev_samples_pos = 22;
136 }
137 }
138
139 263 *got_frame_ptr = 1;
140
141 263 return avpkt->size;
142 }
143
144 const FFCodec ff_adpcm_g722_decoder = {
145 .p.name = "g722",
146 CODEC_LONG_NAME("G.722 ADPCM"),
147 .p.type = AVMEDIA_TYPE_AUDIO,
148 .p.id = AV_CODEC_ID_ADPCM_G722,
149 .priv_data_size = sizeof(G722Context),
150 .init = g722_decode_init,
151 FF_CODEC_DECODE_CB(g722_decode_frame),
152 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
153 .p.priv_class = &g722_decoder_class,
154 };
155