3 * Copyright (c) 2003 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 /* we knowingly overspecify each tag length by one byte to compensate for the mandatory null byte added by av_strlcpy */
55 count += id3v1_set_string(s, "TIT2", buf + 3, 30 + 1); //title
56 count += id3v1_set_string(s, "TPE1", buf + 33, 30 + 1); //author|artist
57 count += id3v1_set_string(s, "TALB", buf + 63, 30 + 1); //album
58 count += id3v1_set_string(s, "TDRL", buf + 93, 4 + 1); //date
59 count += id3v1_set_string(s, "comment", buf + 97, 30 + 1);
60 if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
62 buf[126] = atoi(tag->value);
65 buf[127] = 0xFF; /* default to unknown genre */
66 if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
67 for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
68 if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
78 #define XING_NUM_BAGS 400
79 #define XING_TOC_SIZE 100
80 // maximum size of the xing frame: offset/Xing/flags/frames/size/TOC
81 #define XING_MAX_SIZE (32 + 4 + 4 + 4 + 4 + XING_TOC_SIZE)
83 typedef struct MP3Context {
97 uint64_t bag[XING_NUM_BAGS];
99 int has_variable_bitrate;
101 /* index of the audio stream */
102 int audio_stream_idx;
103 /* number of attached pictures we still need to write */
106 /* audio packets are queued here until we get all the attached pictures */
107 AVPacketList *queue, *queue_end;
110 static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};
113 * Write an empty XING header and initialize respective data.
115 static int mp3_write_xing(AVFormatContext *s)
117 MP3Context *mp3 = s->priv_data;
118 AVCodecContext *codec = s->streams[mp3->audio_stream_idx]->codec;
120 int best_bitrate_idx = -1;
121 int best_bitrate_error= INT_MAX;
123 int32_t header, mask;
125 int srate_idx, ver = 0, i, channels;
127 const char *vendor = (codec->flags & CODEC_FLAG_BITEXACT) ? "Lavf" : LIBAVFORMAT_IDENT;
129 if (!s->pb->seekable || !mp3->write_xing)
132 for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
133 const uint16_t base_freq = avpriv_mpa_freq_tab[i];
135 if (codec->sample_rate == base_freq) ver = 0x3; // MPEG 1
136 else if (codec->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
137 else if (codec->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
143 if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
144 av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing header.\n");
148 switch (codec->channels) {
149 case 1: channels = MPA_MONO; break;
150 case 2: channels = MPA_STEREO; break;
151 default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
152 "not writing Xing header.\n");
156 /* dummy MPEG audio header */
157 header = 0xffU << 24; // sync
158 header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
159 header |= (srate_idx << 2) << 8;
160 header |= channels << 6;
162 for (bitrate_idx=1; bitrate_idx<15; bitrate_idx++) {
164 avpriv_mpegaudio_decode_header(&c, header | (bitrate_idx << (4+8)));
165 error= FFABS(c.bit_rate - codec->bit_rate);
166 if(error < best_bitrate_error){
167 best_bitrate_error= error;
168 best_bitrate_idx = bitrate_idx;
171 av_assert0(best_bitrate_idx >= 0);
173 for (bitrate_idx= best_bitrate_idx;; bitrate_idx++) {
174 if (15 == bitrate_idx)
176 mask = bitrate_idx << (4+8);
178 avpriv_mpegaudio_decode_header(&c, header);
179 xing_offset=xing_offtbl[c.lsf == 1][c.nb_channels == 1];
183 + 4 // frames/size/toc flags
186 + XING_TOC_SIZE // toc
190 if (needed <= c.frame_size)
195 avio_wb32(s->pb, header);
197 ffio_fill(s->pb, 0, xing_offset);
198 mp3->xing_offset = avio_tell(s->pb);
199 ffio_wfourcc(s->pb, "Xing");
200 avio_wb32(s->pb, 0x01 | 0x02 | 0x04); // frames / size / TOC
202 mp3->size = c.frame_size;
207 avio_wb32(s->pb, 0); // frames
208 avio_wb32(s->pb, 0); // size
211 for (i = 0; i < XING_TOC_SIZE; ++i)
212 avio_w8(s->pb, (uint8_t)(255 * i / XING_TOC_SIZE));
214 for (i = 0; i < strlen(vendor); ++i)
215 avio_w8(s->pb, vendor[i]);
218 avio_wb24(s->pb, FFMAX(codec->delay - 528 - 1, 0)<<12);
220 ffio_fill(s->pb, 0, c.frame_size - needed);
226 * Add a frame to XING data.
227 * Following lame's "VbrTag.c".
229 static void mp3_xing_add_frame(MP3Context *mp3, AVPacket *pkt)
235 mp3->size += pkt->size;
237 if (mp3->want == mp3->seen) {
238 mp3->bag[mp3->pos] = mp3->size;
240 if (XING_NUM_BAGS == ++mp3->pos) {
241 /* shrink table to half size by throwing away each second bag. */
242 for (i = 1; i < XING_NUM_BAGS; i += 2)
243 mp3->bag[i >> 1] = mp3->bag[i];
245 /* double wanted amount per bag. */
247 /* adjust current position to half of table size. */
248 mp3->pos = XING_NUM_BAGS / 2;
255 static int mp3_write_audio_packet(AVFormatContext *s, AVPacket *pkt)
257 MP3Context *mp3 = s->priv_data;
259 if (pkt->data && pkt->size >= 4) {
262 uint32_t head = AV_RB32(pkt->data);
264 if (ff_mpa_check_header(head) < 0) {
265 av_log(s, AV_LOG_WARNING, "Audio packet of size %d (starting with %08X...) "
266 "is invalid, writing it anyway.\n", pkt->size, head);
267 return ff_raw_write_packet(s, pkt);
269 avpriv_mpegaudio_decode_header(&c, head);
271 if (!mp3->initial_bitrate)
272 mp3->initial_bitrate = c.bit_rate;
273 if ((c.bit_rate == 0) || (mp3->initial_bitrate != c.bit_rate))
274 mp3->has_variable_bitrate = 1;
276 #ifdef FILTER_VBR_HEADERS
277 /* filter out XING and INFO headers. */
278 base = 4 + xing_offtbl[c.lsf == 1][c.nb_channels == 1];
280 if (base + 4 <= pkt->size) {
281 uint32_t v = AV_RB32(pkt->data + base);
283 if (MKBETAG('X','i','n','g') == v || MKBETAG('I','n','f','o') == v)
287 /* filter out VBRI headers. */
290 if (base + 4 <= pkt->size && MKBETAG('V','B','R','I') == AV_RB32(pkt->data + base))
294 if (mp3->xing_offset)
295 mp3_xing_add_frame(mp3, pkt);
298 return ff_raw_write_packet(s, pkt);
301 static int mp3_queue_flush(AVFormatContext *s)
303 MP3Context *mp3 = s->priv_data;
305 int ret = 0, write = 1;
307 ff_id3v2_finish(&mp3->id3, s->pb);
310 while ((pktl = mp3->queue)) {
311 if (write && (ret = mp3_write_audio_packet(s, &pktl->pkt)) < 0)
313 av_free_packet(&pktl->pkt);
314 mp3->queue = pktl->next;
317 mp3->queue_end = NULL;
321 static void mp3_update_xing(AVFormatContext *s)
323 MP3Context *mp3 = s->priv_data;
326 /* replace "Xing" identification string with "Info" for CBR files. */
327 if (!mp3->has_variable_bitrate) {
328 avio_seek(s->pb, mp3->xing_offset, SEEK_SET);
329 ffio_wfourcc(s->pb, "Info");
332 avio_seek(s->pb, mp3->xing_offset + 8, SEEK_SET);
333 avio_wb32(s->pb, mp3->frames);
334 avio_wb32(s->pb, mp3->size);
336 avio_w8(s->pb, 0); // first toc entry has to be zero.
338 for (i = 1; i < XING_TOC_SIZE; ++i) {
339 int j = i * mp3->pos / XING_TOC_SIZE;
340 int seek_point = 256LL * mp3->bag[j] / mp3->size;
341 avio_w8(s->pb, FFMIN(seek_point, 255));
344 avio_seek(s->pb, 0, SEEK_END);
347 static int mp3_write_trailer(struct AVFormatContext *s)
349 uint8_t buf[ID3v1_TAG_SIZE];
350 MP3Context *mp3 = s->priv_data;
352 if (mp3->pics_to_write) {
353 av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
354 "attached pictures.\n");
358 /* write the id3v1 tag */
359 if (mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
360 avio_write(s->pb, buf, ID3v1_TAG_SIZE);
363 if (mp3->xing_offset)
369 static int query_codec(enum AVCodecID id, int std_compliance)
371 const CodecMime *cm= ff_id3v2_mime_tags;
372 while(cm->id != AV_CODEC_ID_NONE) {
374 return MKTAG('A', 'P', 'I', 'C');
381 AVOutputFormat ff_mp2_muxer = {
383 .long_name = NULL_IF_CONFIG_SMALL("MP2 (MPEG audio layer 2)"),
384 .mime_type = "audio/x-mpeg",
385 .extensions = "mp2,m2a,mpa",
386 .audio_codec = AV_CODEC_ID_MP2,
387 .video_codec = AV_CODEC_ID_NONE,
388 .write_packet = ff_raw_write_packet,
389 .flags = AVFMT_NOTIMESTAMPS,
395 static const AVOption options[] = {
396 { "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
397 offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 0, 4, AV_OPT_FLAG_ENCODING_PARAM},
398 { "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
399 offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
400 { "write_xing", "Write the Xing header containing file duration.",
401 offsetof(MP3Context, write_xing), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
405 static const AVClass mp3_muxer_class = {
406 .class_name = "MP3 muxer",
407 .item_name = av_default_item_name,
409 .version = LIBAVUTIL_VERSION_INT,
412 static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt)
414 MP3Context *mp3 = s->priv_data;
416 if (pkt->stream_index == mp3->audio_stream_idx) {
417 if (mp3->pics_to_write) {
418 /* buffer audio packets until we get all the pictures */
419 AVPacketList *pktl = av_mallocz(sizeof(*pktl));
421 return AVERROR(ENOMEM);
424 pktl->pkt.buf = av_buffer_ref(pkt->buf);
425 if (!pktl->pkt.buf) {
427 return AVERROR(ENOMEM);
431 mp3->queue_end->next = pktl;
434 mp3->queue_end = pktl;
436 return mp3_write_audio_packet(s, pkt);
440 /* warn only once for each stream */
441 if (s->streams[pkt->stream_index]->nb_frames == 1) {
442 av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
443 " ignoring.\n", pkt->stream_index);
445 if (!mp3->pics_to_write || s->streams[pkt->stream_index]->nb_frames >= 1)
448 if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
450 mp3->pics_to_write--;
452 /* flush the buffered audio packets */
453 if (!mp3->pics_to_write &&
454 (ret = mp3_queue_flush(s)) < 0)
462 * Write an ID3v2 header at beginning of stream
465 static int mp3_write_header(struct AVFormatContext *s)
467 MP3Context *mp3 = s->priv_data;
470 if (mp3->id3v2_version &&
471 mp3->id3v2_version != 3 &&
472 mp3->id3v2_version != 4) {
473 av_log(s, AV_LOG_ERROR, "Invalid ID3v2 version requested: %d. Only "
474 "3, 4 or 0 (disabled) are allowed.\n", mp3->id3v2_version);
475 return AVERROR(EINVAL);
478 /* check the streams -- we want exactly one audio and arbitrary number of
479 * video (attached pictures) */
480 mp3->audio_stream_idx = -1;
481 for (i = 0; i < s->nb_streams; i++) {
482 AVStream *st = s->streams[i];
483 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
484 if (mp3->audio_stream_idx >= 0 || st->codec->codec_id != AV_CODEC_ID_MP3) {
485 av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
486 "audio stream is required.\n");
487 return AVERROR(EINVAL);
489 mp3->audio_stream_idx = i;
490 } else if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO) {
491 av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
492 return AVERROR(EINVAL);
495 if (mp3->audio_stream_idx < 0) {
496 av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
497 return AVERROR(EINVAL);
499 mp3->pics_to_write = s->nb_streams - 1;
501 if (mp3->pics_to_write && !mp3->id3v2_version) {
502 av_log(s, AV_LOG_ERROR, "Attached pictures were requested, but the "
503 "ID3v2 header is disabled.\n");
504 return AVERROR(EINVAL);
507 if (mp3->id3v2_version) {
508 ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
509 ret = ff_id3v2_write_metadata(s, &mp3->id3);
514 if (!mp3->pics_to_write) {
515 if (mp3->id3v2_version)
516 ff_id3v2_finish(&mp3->id3, s->pb);
523 AVOutputFormat ff_mp3_muxer = {
525 .long_name = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
526 .mime_type = "audio/x-mpeg",
528 .priv_data_size = sizeof(MP3Context),
529 .audio_codec = AV_CODEC_ID_MP3,
530 .video_codec = AV_CODEC_ID_PNG,
531 .write_header = mp3_write_header,
532 .write_packet = mp3_write_packet,
533 .write_trailer = mp3_write_trailer,
534 .query_codec = query_codec,
535 .flags = AVFMT_NOTIMESTAMPS,
536 .priv_class = &mp3_muxer_class,