FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/s302menc.c
Date: 2026-01-23 19:11:46
Exec Total Coverage
Lines: 48 93 51.6%
Functions: 2 2 100.0%
Branches: 16 49 32.7%
Line Branch Exec Source
1 /*
2 * SMPTE 302M encoder
3 * Copyright (c) 2010 Google, Inc.
4 * Copyright (c) 2013 Darryl Wallace <wallacdj@gmail.com>
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/channel_layout.h"
24 #include "libavutil/reverse.h"
25 #include "avcodec.h"
26 #include "codec_internal.h"
27 #include "encode.h"
28 #include "mathops.h"
29 #include "put_bits.h"
30
31 #define AES3_HEADER_LEN 4
32
33 typedef struct S302MEncContext {
34 uint8_t framing_index; /* Set for even channels on multiple of 192 samples */
35 } S302MEncContext;
36
37 1 static av_cold int s302m_encode_init(AVCodecContext *avctx)
38 {
39 1 S302MEncContext *s = avctx->priv_data;
40
41
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 1 if (avctx->ch_layout.nb_channels & 1 || avctx->ch_layout.nb_channels > 8) {
42 ✗ av_log(avctx, AV_LOG_ERROR,
43 "Encoding %d channel(s) is not allowed. Only 2, 4, 6 and 8 channels are supported.\n",
44 avctx->ch_layout.nb_channels);
45 ✗ return AVERROR(EINVAL);
46 }
47
48
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 1 switch (avctx->sample_fmt) {
49 1 case AV_SAMPLE_FMT_S16:
50 1 avctx->bits_per_raw_sample = 16;
51 1 break;
52 ✗ case AV_SAMPLE_FMT_S32:
53 ✗ if (avctx->bits_per_raw_sample > 20) {
54 ✗ if (avctx->bits_per_raw_sample > 24)
55 ✗ av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
56 ✗ avctx->bits_per_raw_sample = 24;
57 ✗ } else if (!avctx->bits_per_raw_sample) {
58 ✗ avctx->bits_per_raw_sample = 24;
59 ✗ } else if (avctx->bits_per_raw_sample <= 20) {
60 ✗ avctx->bits_per_raw_sample = 20;
61 }
62 }
63
64 1 avctx->frame_size = 0;
65 1 avctx->bit_rate = 48000 * avctx->ch_layout.nb_channels *
66 1 (avctx->bits_per_raw_sample + 4);
67 1 s->framing_index = 0;
68
69 1 return 0;
70 }
71
72 66 static int s302m_encode2_frame(AVCodecContext *avctx, AVPacket *avpkt,
73 const AVFrame *frame, int *got_packet_ptr)
74 {
75 66 S302MEncContext *s = avctx->priv_data;
76 66 const int nb_channels = avctx->ch_layout.nb_channels;
77 66 const int buf_size = AES3_HEADER_LEN +
78 66 (frame->nb_samples * nb_channels *
79 66 (avctx->bits_per_raw_sample + 4)) / 8;
80 int ret, c, channels;
81 uint8_t *o;
82 PutBitContext pb;
83
84
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 66 if (buf_size - AES3_HEADER_LEN > UINT16_MAX) {
85 ✗ av_log(avctx, AV_LOG_ERROR, "number of samples in frame too big\n");
86 ✗ return AVERROR(EINVAL);
87 }
88
89
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 66 if ((ret = ff_get_encode_buffer(avctx, avpkt, buf_size, 0)) < 0)
90 ✗ return ret;
91
92 66 o = avpkt->data;
93 66 init_put_bits(&pb, o, buf_size);
94 66 put_bits(&pb, 16, buf_size - AES3_HEADER_LEN);
95 66 put_bits(&pb, 2, (nb_channels - 2) >> 1); // number of channels
96 66 put_bits(&pb, 8, 0); // channel ID
97 66 put_bits(&pb, 2, (avctx->bits_per_raw_sample - 16) / 4); // bits per samples (0 = 16bit, 1 = 20bit, 2 = 24bit)
98 66 put_bits(&pb, 4, 0); // alignments
99 66 flush_put_bits(&pb);
100 66 o += AES3_HEADER_LEN;
101
102
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 66 if (avctx->bits_per_raw_sample == 24) {
103 ✗ const uint32_t *samples = (uint32_t *)frame->data[0];
104
105 ✗ for (c = 0; c < frame->nb_samples; c++) {
106 ✗ uint8_t vucf = s->framing_index == 0 ? 0x10: 0;
107
108 ✗ for (channels = 0; channels < nb_channels; channels += 2) {
109 ✗ o[0] = ff_reverse[(samples[0] & 0x0000FF00) >> 8];
110 ✗ o[1] = ff_reverse[(samples[0] & 0x00FF0000) >> 16];
111 ✗ o[2] = ff_reverse[(samples[0] & 0xFF000000) >> 24];
112 ✗ o[3] = ff_reverse[(samples[1] & 0x00000F00) >> 4] | vucf;
113 ✗ o[4] = ff_reverse[(samples[1] & 0x000FF000) >> 12];
114 ✗ o[5] = ff_reverse[(samples[1] & 0x0FF00000) >> 20];
115 ✗ o[6] = ff_reverse[(samples[1] & 0xF0000000) >> 28];
116 ✗ o += 7;
117 ✗ samples += 2;
118 }
119
120 ✗ s->framing_index++;
121 ✗ if (s->framing_index >= 192)
122 ✗ s->framing_index = 0;
123 }
124
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 66 } else if (avctx->bits_per_raw_sample == 20) {
125 ✗ const uint32_t *samples = (uint32_t *)frame->data[0];
126
127 ✗ for (c = 0; c < frame->nb_samples; c++) {
128 ✗ uint8_t vucf = s->framing_index == 0 ? 0x80: 0;
129
130 ✗ for (channels = 0; channels < nb_channels; channels += 2) {
131 ✗ o[0] = ff_reverse[ (samples[0] & 0x000FF000) >> 12];
132 ✗ o[1] = ff_reverse[ (samples[0] & 0x0FF00000) >> 20];
133 ✗ o[2] = ff_reverse[((samples[0] & 0xF0000000) >> 28) | vucf];
134 ✗ o[3] = ff_reverse[ (samples[1] & 0x000FF000) >> 12];
135 ✗ o[4] = ff_reverse[ (samples[1] & 0x0FF00000) >> 20];
136 ✗ o[5] = ff_reverse[ (samples[1] & 0xF0000000) >> 28];
137 ✗ o += 6;
138 ✗ samples += 2;
139 }
140
141 ✗ s->framing_index++;
142 ✗ if (s->framing_index >= 192)
143 ✗ s->framing_index = 0;
144 }
145
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 66 } else if (avctx->bits_per_raw_sample == 16) {
146 66 const uint16_t *samples = (uint16_t *)frame->data[0];
147
148
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 288066 for (c = 0; c < frame->nb_samples; c++) {
149
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 288000 uint8_t vucf = s->framing_index == 0 ? 0x10 : 0;
150
151
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 576000 for (channels = 0; channels < nb_channels; channels += 2) {
152 288000 o[0] = ff_reverse[ samples[0] & 0xFF];
153 288000 o[1] = ff_reverse[(samples[0] & 0xFF00) >> 8];
154 288000 o[2] = ff_reverse[(samples[1] & 0x0F) << 4] | vucf;
155 288000 o[3] = ff_reverse[(samples[1] & 0x0FF0) >> 4];
156 288000 o[4] = ff_reverse[(samples[1] & 0xF000) >> 12];
157 288000 o += 5;
158 288000 samples += 2;
159
160 }
161
162 288000 s->framing_index++;
163
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 288000 if (s->framing_index >= 192)
164 1500 s->framing_index = 0;
165 }
166 }
167
168 66 *got_packet_ptr = 1;
169
170 66 return 0;
171 }
172
173 const FFCodec ff_s302m_encoder = {
174 .p.name = "s302m",
175 CODEC_LONG_NAME("SMPTE 302M"),
176 .p.type = AVMEDIA_TYPE_AUDIO,
177 .p.id = AV_CODEC_ID_S302M,
178 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_EXPERIMENTAL |
179 AV_CODEC_CAP_VARIABLE_FRAME_SIZE |
180 AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
181 .priv_data_size = sizeof(S302MEncContext),
182 .init = s302m_encode_init,
183 FF_CODEC_ENCODE_CB(s302m_encode2_frame),
184 CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S16),
185 CODEC_SAMPLERATES(48000),
186 };
187