1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* MP3 muxer
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "avio_internal.h"
#include "id3v1.h"
#include "id3v2.h"
#include "rawenc.h"
#include "libavutil/avstring.h"
#include "libavcodec/mpegaudio.h"
#include "libavcodec/mpegaudiodata.h"
#include "libavcodec/mpegaudiodecheader.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "libavutil/dict.h"
static int id3v1_set_string(AVFormatContext *s, const char *key,
uint8_t *buf, int buf_size)
{
AVDictionaryEntry *tag;
if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
av_strlcpy(buf, tag->value, buf_size);
return !!tag;
}
static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
{
AVDictionaryEntry *tag;
int i, count = 0;
memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
buf[0] = 'T';
buf[1] = 'A';
buf[2] = 'G';
count += id3v1_set_string(s, "TIT2", buf + 3, 30); //title
count += id3v1_set_string(s, "TPE1", buf + 33, 30); //author|artist
count += id3v1_set_string(s, "TALB", buf + 63, 30); //album
count += id3v1_set_string(s, "TDRL", buf + 93, 4); //date
count += id3v1_set_string(s, "comment", buf + 97, 30);
if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
buf[125] = 0;
buf[126] = atoi(tag->value);
count++;
}
buf[127] = 0xFF; /* default to unknown genre */
if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
buf[127] = i;
count++;
break;
}
}
}
return count;
}
typedef struct MP3Context {
const AVClass *class;
int id3v2_version;
int write_id3v1;
int64_t nb_frames_offset;
} MP3Context;
/* insert a dummy frame containing number of frames */
static void mp3_write_xing(AVFormatContext *s)
{
MP3Context *mp3 = s->priv_data;
AVCodecContext *codec = s->streams[0]->codec;
int bitrate_idx = 1; // 32 kbps
int64_t xing_offset = (codec->channels == 2) ? 32 : 17;
int32_t header;
MPADecodeHeader mpah;
int srate_idx, i, channels;
if (!s->pb->seekable)
return;
for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++)
if (avpriv_mpa_freq_tab[i] == codec->sample_rate) {
srate_idx = i;
break;
}
if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n");
return;
}
switch (codec->channels) {
case 1: channels = MPA_MONO; break;
case 2: channels = MPA_STEREO; break;
default: av_log(s, AV_LOG_ERROR, "Unsupported number of channels.\n"); return;
}
/* dummy MPEG audio header */
header = 0xff << 24; // sync
header |= (0x7 << 5 | 0x3 << 3 | 0x1 << 1 | 0x1) << 16; // sync/mpeg-1/layer 3/no crc*/
header |= (bitrate_idx << 4 | srate_idx << 2) << 8;
header |= channels << 6;
avio_wb32(s->pb, header);
avpriv_mpegaudio_decode_header(&mpah, header);
ffio_fill(s->pb, 0, xing_offset);
ffio_wfourcc(s->pb, "Xing");
avio_wb32(s->pb, 0x1); // only number of frames
mp3->nb_frames_offset = avio_tell(s->pb);
avio_wb32(s->pb, 0);
mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4;
ffio_fill(s->pb, 0, mpah.frame_size);
}
static int mp3_write_trailer(struct AVFormatContext *s)
{
uint8_t buf[ID3v1_TAG_SIZE];
MP3Context *mp3 = s->priv_data;
/* write the id3v1 tag */
if (mp3 && mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
avio_write(s->pb, buf, ID3v1_TAG_SIZE);
}
/* write number of frames */
if (mp3 && mp3->nb_frames_offset) {
avio_seek(s->pb, mp3->nb_frames_offset, SEEK_SET);
avio_wb32(s->pb, s->streams[0]->nb_frames);
avio_seek(s->pb, 0, SEEK_END);
}
avio_flush(s->pb);
return 0;
}
#if CONFIG_MP2_MUXER
AVOutputFormat ff_mp2_muxer = {
.name = "mp2",
.long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 2"),
.mime_type = "audio/x-mpeg",
.extensions = "mp2,m2a",
.audio_codec = CODEC_ID_MP2,
.video_codec = CODEC_ID_NONE,
.write_packet = ff_raw_write_packet,
.write_trailer = mp3_write_trailer,
};
#endif
#if CONFIG_MP3_MUXER
static const AVOption options[] = {
{ "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.dbl = 4}, 3, 4, AV_OPT_FLAG_ENCODING_PARAM},
{ "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.dbl = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{ NULL },
};
static const AVClass mp3_muxer_class = {
.class_name = "MP3 muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
/**
* Write an ID3v2 header at beginning of stream
*/
static int mp3_write_header(struct AVFormatContext *s)
{
MP3Context *mp3 = s->priv_data;
int ret;
ret = ff_id3v2_write_simple(s, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
if (ret < 0)
return ret;
if (s->pb->seekable)
mp3_write_xing(s);
return 0;
}
AVOutputFormat ff_mp3_muxer = {
.name = "mp3",
.long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 3"),
.mime_type = "audio/x-mpeg",
.extensions = "mp3",
.priv_data_size = sizeof(MP3Context),
.audio_codec = CODEC_ID_MP3,
.video_codec = CODEC_ID_NONE,
.write_header = mp3_write_header,
.write_packet = ff_raw_write_packet,
.write_trailer = mp3_write_trailer,
.flags = AVFMT_NOTIMESTAMPS,
.priv_class = &mp3_muxer_class,
};
#endif
|
