3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "avio_internal.h"
28 #include "libavutil/avstring.h"
29 #include "libavcodec/mpegaudio.h"
30 #include "libavcodec/mpegaudiodata.h"
31 #include "libavcodec/mpegaudiodecheader.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/dict.h"
36 static int id3v1_set_string(AVFormatContext *s, const char *key,
37 uint8_t *buf, int buf_size)
39 AVDictionaryEntry *tag;
40 if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
41 av_strlcpy(buf, tag->value, buf_size);
45 static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
47 AVDictionaryEntry *tag;
50 memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
54 count += id3v1_set_string(s, "TIT2", buf + 3, 30); //title
55 count += id3v1_set_string(s, "TPE1", buf + 33, 30); //author|artist
56 count += id3v1_set_string(s, "TALB", buf + 63, 30); //album
57 count += id3v1_set_string(s, "TDRL", buf + 93, 4); //date
58 count += id3v1_set_string(s, "comment", buf + 97, 30);
59 if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
61 buf[126] = atoi(tag->value);
64 buf[127] = 0xFF; /* default to unknown genre */
65 if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
66 for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
67 if (!strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
79 static void id3v2_put_size(AVFormatContext *s, int size)
81 avio_w8(s->pb, size >> 21 & 0x7f);
82 avio_w8(s->pb, size >> 14 & 0x7f);
83 avio_w8(s->pb, size >> 7 & 0x7f);
84 avio_w8(s->pb, size & 0x7f);
87 static int string_is_ascii(const uint8_t *str)
89 while (*str && *str < 128) str++;
94 * Write a text frame with one (normal frames) or two (TXXX frames) strings
95 * according to encoding (only UTF-8 or UTF-16+BOM supported).
96 * @return number of bytes written or a negative error code.
98 static int id3v2_put_ttag(AVFormatContext *s, const char *str1, const char *str2,
99 uint32_t tag, enum ID3v2Encoding enc)
103 int (*put)(AVIOContext*, const char*);
104 AVIOContext *dyn_buf;
105 if (avio_open_dyn_buf(&dyn_buf) < 0)
106 return AVERROR(ENOMEM);
108 /* check if the strings are ASCII-only and use UTF16 only if
110 if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
111 (!str2 || string_is_ascii(str2)))
112 enc = ID3v2_ENCODING_ISO8859;
114 avio_w8(dyn_buf, enc);
115 if (enc == ID3v2_ENCODING_UTF16BOM) {
116 avio_wl16(dyn_buf, 0xFEFF); /* BOM */
117 put = avio_put_str16le;
124 len = avio_close_dyn_buf(dyn_buf, &pb);
126 avio_wb32(s->pb, tag);
127 id3v2_put_size(s, len);
129 avio_write(s->pb, pb, len);
132 return len + ID3v2_HEADER_SIZE;
135 typedef struct MP3Context {
136 const AVClass *class;
139 int64_t nb_frames_offset;
142 static int mp3_write_trailer(struct AVFormatContext *s)
144 uint8_t buf[ID3v1_TAG_SIZE];
145 MP3Context *mp3 = s->priv_data;
147 /* write the id3v1 tag */
148 if (mp3 && mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
149 avio_write(s->pb, buf, ID3v1_TAG_SIZE);
152 /* write number of frames */
153 if (mp3 && mp3->nb_frames_offset) {
154 avio_seek(s->pb, mp3->nb_frames_offset, SEEK_SET);
155 avio_wb32(s->pb, s->streams[0]->nb_frames);
156 avio_seek(s->pb, 0, SEEK_END);
165 AVOutputFormat ff_mp2_muxer = {
167 .long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 2"),
168 .mime_type = "audio/x-mpeg",
169 .extensions = "mp2,m2a",
170 .audio_codec = CODEC_ID_MP2,
171 .video_codec = CODEC_ID_NONE,
172 .write_packet = ff_raw_write_packet,
173 .write_trailer = mp3_write_trailer,
179 static const AVOption options[] = {
180 { "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
181 offsetof(MP3Context, id3v2_version), FF_OPT_TYPE_INT, {.dbl = 4}, 3, 4, AV_OPT_FLAG_ENCODING_PARAM},
182 { "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
183 offsetof(MP3Context, write_id3v1), FF_OPT_TYPE_INT, {.dbl = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
187 static const AVClass mp3_muxer_class = {
188 .class_name = "MP3 muxer",
189 .item_name = av_default_item_name,
191 .version = LIBAVUTIL_VERSION_INT,
194 static int id3v2_check_write_tag(AVFormatContext *s, AVDictionaryEntry *t, const char table[][4],
195 enum ID3v2Encoding enc)
200 if (t->key[0] != 'T' || strlen(t->key) != 4)
202 tag = AV_RB32(t->key);
203 for (i = 0; *table[i]; i++)
204 if (tag == AV_RB32(table[i]))
205 return id3v2_put_ttag(s, t->value, NULL, tag, enc);
209 /* insert a dummy frame containing number of frames */
210 static void mp3_write_xing(AVFormatContext *s)
212 AVCodecContext *codec = s->streams[0]->codec;
213 MP3Context *mp3 = s->priv_data;
214 int bitrate_idx = 1; // 32 kbps
215 int64_t xing_offset = (codec->channels == 2) ? 32 : 17;
217 MPADecodeHeader mpah;
218 int srate_idx, i, channels;
220 for (i = 0; i < FF_ARRAY_ELEMS(ff_mpa_freq_tab); i++)
221 if (ff_mpa_freq_tab[i] == codec->sample_rate) {
225 if (i == FF_ARRAY_ELEMS(ff_mpa_freq_tab)) {
226 av_log(s, AV_LOG_ERROR, "Unsupported sample rate.\n");
230 switch (codec->channels) {
231 case 1: channels = MPA_MONO; break;
232 case 2: channels = MPA_STEREO; break;
233 default: av_log(s, AV_LOG_ERROR, "Unsupported number of channels.\n"); return;
236 /* dummy MPEG audio header */
237 header = 0xff << 24; // sync
238 header |= (0x7 << 5 | 0x3 << 3 | 0x1 << 1 | 0x1) << 16; // sync/mpeg-1/layer 3/no crc*/
239 header |= (bitrate_idx << 4 | srate_idx << 2) << 8;
240 header |= channels << 6;
241 avio_wb32(s->pb, header);
243 ff_mpegaudio_decode_header(&mpah, header);
245 ffio_fill(s->pb, 0, xing_offset);
246 ffio_wfourcc(s->pb, "Xing");
247 avio_wb32(s->pb, 0x1); // only number of frames
248 mp3->nb_frames_offset = avio_tell(s->pb);
251 mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4;
252 ffio_fill(s->pb, 0, mpah.frame_size);
256 * Write an ID3v2 header at beginning of stream
259 static int mp3_write_header(struct AVFormatContext *s)
261 MP3Context *mp3 = s->priv_data;
262 AVDictionaryEntry *t = NULL;
263 int totlen = 0, enc = mp3->id3v2_version == 3 ? ID3v2_ENCODING_UTF16BOM :
265 int64_t size_pos, cur_pos;
267 avio_wb32(s->pb, MKBETAG('I', 'D', '3', mp3->id3v2_version));
269 avio_w8(s->pb, 0); /* flags */
271 /* reserve space for size */
272 size_pos = avio_tell(s->pb);
275 ff_metadata_conv(&s->metadata, ff_id3v2_34_metadata_conv, NULL);
276 if (mp3->id3v2_version == 4)
277 ff_metadata_conv(&s->metadata, ff_id3v2_4_metadata_conv, NULL);
279 while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
282 if ((ret = id3v2_check_write_tag(s, t, ff_id3v2_tags, enc)) > 0) {
286 if ((ret = id3v2_check_write_tag(s, t, mp3->id3v2_version == 3 ?
287 ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
292 /* unknown tag, write as TXXX frame */
293 if ((ret = id3v2_put_ttag(s, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
298 cur_pos = avio_tell(s->pb);
299 avio_seek(s->pb, size_pos, SEEK_SET);
300 id3v2_put_size(s, totlen);
301 avio_seek(s->pb, cur_pos, SEEK_SET);
309 AVOutputFormat ff_mp3_muxer = {
311 .long_name = NULL_IF_CONFIG_SMALL("MPEG audio layer 3"),
312 .mime_type = "audio/x-mpeg",
314 .priv_data_size = sizeof(MP3Context),
315 .audio_codec = CODEC_ID_MP3,
316 .video_codec = CODEC_ID_NONE,
317 .write_header = mp3_write_header,
318 .write_packet = ff_raw_write_packet,
319 .write_trailer = mp3_write_trailer,
320 .flags = AVFMT_NOTIMESTAMPS,
321 .priv_class = &mp3_muxer_class,