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
23 #include "avio_internal.h"
27 #include "libavutil/avstring.h"
28 #include "libavcodec/mpegaudio.h"
29 #include "libavcodec/mpegaudiodata.h"
30 #include "libavcodec/mpegaudiodecheader.h"
31 #include "libavutil/intreadwrite.h"
32 #include "libavutil/opt.h"
33 #include "libavutil/dict.h"
34 #include "libavutil/avassert.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 (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
77 typedef struct MP3Context {
82 int64_t nb_frames_offset;
84 /* index of the audio stream */
86 /* number of attached pictures we still need to write */
89 /* audio packets are queued here until we get all the attached pictures */
90 AVPacketList *queue, *queue_end;
93 static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};
95 /* insert a dummy frame containing number of frames */
96 static void mp3_write_xing(AVFormatContext *s)
98 MP3Context *mp3 = s->priv_data;
99 AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec;
100 int bitrate_idx = 1; // 32 kbps
102 MPADecodeHeader mpah;
103 int srate_idx, i, channels;
107 if (!s->pb->seekable)
110 for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
111 const uint16_t base_freq = avpriv_mpa_freq_tab[i];
113 if (codec->sample_rate == base_freq) ver = 0x3; // MPEG 1
114 else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
115 else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
121 if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
122 av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing "
127 switch (codec->channels) {
128 case 1: channels = MPA_MONO; break;
129 case 2: channels = MPA_STEREO; break;
130 default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
131 "not writing Xing header.\n");
135 /* dummy MPEG audio header */
136 header = 0xff << 24; // sync
137 header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
138 header |= (bitrate_idx << 4 | srate_idx << 2) << 8;
139 header |= channels << 6;
140 avio_wb32(s->pb, header);
142 avpriv_mpegaudio_decode_header(&mpah, header);
144 xing_offset = xing_offtbl[ver != 3][codec->channels == 1];
145 ffio_fill(s->pb, 0, xing_offset);
146 ffio_wfourcc(s->pb, "Xing");
147 avio_wb32(s->pb, 0x1); // only number of frames
148 mp3->nb_frames_offset = avio_tell(s->pb);
151 mpah.frame_size -= 4 + xing_offset + 4 + 4 + 4;
152 ffio_fill(s->pb, 0, mpah.frame_size);
155 static int mp3_queue_flush(AVFormatContext *s)
157 MP3Context *mp3 = s->priv_data;
159 int ret = 0, write = 1;
161 ff_id3v2_finish(&mp3->id3, s->pb);
164 while ((pktl = mp3->queue)) {
165 if (write && (ret = ff_raw_write_packet(s, &pktl->pkt)) < 0)
167 av_free_packet(&pktl->pkt);
168 mp3->queue = pktl->next;
171 mp3->queue_end = NULL;
175 static int mp3_write_trailer(struct AVFormatContext *s)
177 uint8_t buf[ID3v1_TAG_SIZE];
178 MP3Context *mp3 = s->priv_data;
180 if (mp3 && mp3->pics_to_write) {
181 av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
182 "attached pictures.\n");
186 /* write the id3v1 tag */
187 if (mp3 && mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
188 avio_write(s->pb, buf, ID3v1_TAG_SIZE);
191 /* write number of frames */
192 if (mp3 && mp3->nb_frames_offset) {
193 avio_seek(s->pb, mp3->nb_frames_offset, SEEK_SET);
194 avio_wb32(s->pb, s->streams[mp3->audio_stream_idx]->nb_frames);
195 avio_seek(s->pb, 0, SEEK_END);
204 AVOutputFormat ff_mp2_muxer = {
206 .long_name = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
207 .mime_type = "audio/x-mpeg",
208 .extensions = "mp2,m2a",
209 .audio_codec = AV_CODEC_ID_MP2,
210 .video_codec = AV_CODEC_ID_NONE,
211 .write_packet = ff_raw_write_packet,
212 .write_trailer = mp3_write_trailer,
213 .flags = AVFMT_NOTIMESTAMPS,
219 static const AVOption options[] = {
220 { "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
221 offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 3, 4, AV_OPT_FLAG_ENCODING_PARAM},
222 { "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
223 offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
227 static const AVClass mp3_muxer_class = {
228 .class_name = "MP3 muxer",
229 .item_name = av_default_item_name,
231 .version = LIBAVUTIL_VERSION_INT,
234 static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt)
236 MP3Context *mp3 = s->priv_data;
238 if (pkt->stream_index == mp3->audio_stream_idx) {
239 if (mp3->pics_to_write) {
240 /* buffer audio packets until we get all the pictures */
241 AVPacketList *pktl = av_mallocz(sizeof(*pktl));
243 return AVERROR(ENOMEM);
246 pkt->destruct = NULL;
249 mp3->queue_end->next = pktl;
252 mp3->queue_end = pktl;
254 return ff_raw_write_packet(s, pkt);
258 /* warn only once for each stream */
259 if (s->streams[pkt->stream_index]->nb_frames == 1) {
260 av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
261 " ignoring.\n", pkt->stream_index);
263 if (!mp3->pics_to_write || s->streams[pkt->stream_index]->nb_frames >= 1)
266 if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
268 mp3->pics_to_write--;
270 /* flush the buffered audio packets */
271 if (!mp3->pics_to_write &&
272 (ret = mp3_queue_flush(s)) < 0)
280 * Write an ID3v2 header at beginning of stream
283 static int mp3_write_header(struct AVFormatContext *s)
285 MP3Context *mp3 = s->priv_data;
288 /* check the streams -- we want exactly one audio and arbitrary number of
289 * video (attached pictures) */
290 mp3->audio_stream_idx = -1;
291 for (i = 0; i < s->nb_streams; i++) {
292 AVStream *st = s->streams[i];
293 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
294 if (mp3->audio_stream_idx >= 0 || st->codec->codec_id != AV_CODEC_ID_MP3) {
295 av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
296 "audio stream is required.\n");
297 return AVERROR(EINVAL);
299 mp3->audio_stream_idx = i;
300 } else if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) {
301 av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
302 return AVERROR(EINVAL);
305 if (mp3->audio_stream_idx < 0) {
306 av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
307 return AVERROR(EINVAL);
309 mp3->pics_to_write = s->nb_streams - 1;
311 ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
312 ret = ff_id3v2_write_metadata(s, &mp3->id3);
316 if (!mp3->pics_to_write) {
317 ff_id3v2_finish(&mp3->id3, s->pb);
324 AVOutputFormat ff_mp3_muxer = {
326 .long_name = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
327 .mime_type = "audio/x-mpeg",
329 .priv_data_size = sizeof(MP3Context),
330 .audio_codec = AV_CODEC_ID_MP3,
331 .video_codec = AV_CODEC_ID_PNG,
332 .write_header = mp3_write_header,
333 .write_packet = mp3_write_packet,
334 .write_trailer = mp3_write_trailer,
335 .flags = AVFMT_NOTIMESTAMPS,
336 .priv_class = &mp3_muxer_class,