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/libavformat/mp3enc.c

http://github.com/FFmpeg/FFmpeg
C | 653 lines | 489 code | 104 blank | 60 comment | 118 complexity | ee1181aadda6ba4fcafd7d48f3dac6a1 MD5 | raw file
  1/*
  2 * MP3 muxer
  3 * Copyright (c) 2003 Fabrice Bellard
  4 *
  5 * This file is part of FFmpeg.
  6 *
  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.
 11 *
 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.
 16 *
 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
 20 */
 21
 22#include "avformat.h"
 23#include "avio_internal.h"
 24#include "id3v1.h"
 25#include "id3v2.h"
 26#include "rawenc.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"
 35#include "libavutil/crc.h"
 36#include "libavutil/mathematics.h"
 37#include "libavutil/replaygain.h"
 38
 39static int id3v1_set_string(AVFormatContext *s, const char *key,
 40                            uint8_t *buf, int buf_size)
 41{
 42    AVDictionaryEntry *tag;
 43    if ((tag = av_dict_get(s->metadata, key, NULL, 0)))
 44        av_strlcpy(buf, tag->value, buf_size);
 45    return !!tag;
 46}
 47
 48// refer to: http://id3.org/ID3v1
 49static int id3v1_create_tag(AVFormatContext *s, uint8_t *buf)
 50{
 51    AVDictionaryEntry *tag;
 52    int i, count = 0;
 53
 54    memset(buf, 0, ID3v1_TAG_SIZE); /* fail safe */
 55    buf[0] = 'T';
 56    buf[1] = 'A';
 57    buf[2] = 'G';
 58    /* we knowingly overspecify each tag length by one byte to compensate for the mandatory null byte added by av_strlcpy */
 59    count += id3v1_set_string(s, "TIT2",    buf +  3, 30 + 1);       //title
 60    count += id3v1_set_string(s, "TPE1",    buf + 33, 30 + 1);       //author|artist
 61    count += id3v1_set_string(s, "TALB",    buf + 63, 30 + 1);       //album
 62    if ((tag = av_dict_get(s->metadata, "TYER", NULL, 0))) {         //year
 63        av_strlcpy(buf + 93, tag->value, 4 + 1);
 64        count++;
 65    } else if ((tag = av_dict_get(s->metadata, "TDRC", NULL, 0))) {
 66        av_strlcpy(buf + 93, tag->value, 4 + 1);
 67        count++;
 68    } else if ((tag = av_dict_get(s->metadata, "TDAT", NULL, 0))) {
 69        av_strlcpy(buf + 93, tag->value, 4 + 1);
 70        count++;
 71    }
 72
 73    count += id3v1_set_string(s, "comment", buf + 97, 30 + 1);
 74    if ((tag = av_dict_get(s->metadata, "TRCK", NULL, 0))) { //track
 75        buf[125] = 0;
 76        buf[126] = atoi(tag->value);
 77        count++;
 78    }
 79    buf[127] = 0xFF; /* default to unknown genre */
 80    if ((tag = av_dict_get(s->metadata, "TCON", NULL, 0))) { //genre
 81        for(i = 0; i <= ID3v1_GENRE_MAX; i++) {
 82            if (!av_strcasecmp(tag->value, ff_id3v1_genre_str[i])) {
 83                buf[127] = i;
 84                count++;
 85                break;
 86            }
 87        }
 88    }
 89    return count;
 90}
 91
 92#define XING_NUM_BAGS 400
 93#define XING_TOC_SIZE 100
 94// size of the XING/LAME data, starting from the Xing tag
 95#define XING_SIZE 156
 96
 97typedef struct MP3Context {
 98    const AVClass *class;
 99    ID3v2EncContext id3;
100    int id3v2_version;
101    int write_id3v1;
102    int write_xing;
103
104    /* xing header */
105    // a buffer containing the whole XING/LAME frame
106    uint8_t *xing_frame;
107    int      xing_frame_size;
108
109    AVCRC    audio_crc;     // CRC of the audio data
110    uint32_t audio_size;    // total size of the audio data
111
112    // offset of the XING/LAME frame in the file
113    int64_t  xing_frame_offset;
114    // offset of the XING/INFO tag in the frame
115    int xing_offset;
116
117    int32_t frames;
118    int32_t size;
119    uint32_t want;
120    uint32_t seen;
121    uint32_t pos;
122    uint64_t bag[XING_NUM_BAGS];
123    int initial_bitrate;
124    int has_variable_bitrate;
125    int delay;
126    int padding;
127
128    /* index of the audio stream */
129    int audio_stream_idx;
130    /* number of attached pictures we still need to write */
131    int pics_to_write;
132
133    /* audio packets are queued here until we get all the attached pictures */
134    AVPacketList *queue, *queue_end;
135} MP3Context;
136
137static const uint8_t xing_offtbl[2][2] = {{32, 17}, {17, 9}};
138
139/*
140 * Write an empty XING header and initialize respective data.
141 */
142static int mp3_write_xing(AVFormatContext *s)
143{
144    MP3Context       *mp3 = s->priv_data;
145    AVCodecParameters *par = s->streams[mp3->audio_stream_idx]->codecpar;
146    AVDictionaryEntry *enc = av_dict_get(s->streams[mp3->audio_stream_idx]->metadata, "encoder", NULL, 0);
147    AVIOContext *dyn_ctx;
148    int32_t        header;
149    MPADecodeHeader  mpah;
150    int srate_idx, i, channels;
151    int bitrate_idx;
152    int best_bitrate_idx = -1;
153    int best_bitrate_error = INT_MAX;
154    int ret;
155    int ver = 0;
156    int bytes_needed;
157
158    if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL) || !mp3->write_xing)
159        return 0;
160
161    for (i = 0; i < FF_ARRAY_ELEMS(avpriv_mpa_freq_tab); i++) {
162        const uint16_t base_freq = avpriv_mpa_freq_tab[i];
163
164        if      (par->sample_rate == base_freq)     ver = 0x3; // MPEG 1
165        else if (par->sample_rate == base_freq / 2) ver = 0x2; // MPEG 2
166        else if (par->sample_rate == base_freq / 4) ver = 0x0; // MPEG 2.5
167        else continue;
168
169        srate_idx = i;
170        break;
171    }
172    if (i == FF_ARRAY_ELEMS(avpriv_mpa_freq_tab)) {
173        av_log(s, AV_LOG_WARNING, "Unsupported sample rate, not writing Xing header.\n");
174        return -1;
175    }
176
177    switch (par->channels) {
178    case 1:  channels = MPA_MONO;                                          break;
179    case 2:  channels = MPA_STEREO;                                        break;
180    default: av_log(s, AV_LOG_WARNING, "Unsupported number of channels, "
181                    "not writing Xing header.\n");
182             return -1;
183    }
184
185    /* dummy MPEG audio header */
186    header  =  0xffU                                 << 24; // sync
187    header |= (0x7 << 5 | ver << 3 | 0x1 << 1 | 0x1) << 16; // sync/audio-version/layer 3/no crc*/
188    header |= (srate_idx << 2) << 8;
189    header |= channels << 6;
190
191    for (bitrate_idx = 1; bitrate_idx < 15; bitrate_idx++) {
192        int bit_rate = 1000 * avpriv_mpa_bitrate_tab[ver != 3][3 - 1][bitrate_idx];
193        int error    = FFABS(bit_rate - par->bit_rate);
194
195        if (error < best_bitrate_error) {
196            best_bitrate_error = error;
197            best_bitrate_idx   = bitrate_idx;
198        }
199    }
200    av_assert0(best_bitrate_idx >= 0);
201
202    for (bitrate_idx = best_bitrate_idx; ; bitrate_idx++) {
203        int32_t mask = bitrate_idx << (4 + 8);
204        if (15 == bitrate_idx)
205            return -1;
206        header |= mask;
207
208        ret = avpriv_mpegaudio_decode_header(&mpah, header);
209        av_assert0(ret >= 0);
210        mp3->xing_offset = xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1] + 4;
211        bytes_needed     = mp3->xing_offset + XING_SIZE;
212
213        if (bytes_needed <= mpah.frame_size)
214            break;
215
216        header &= ~mask;
217    }
218
219    ret = avio_open_dyn_buf(&dyn_ctx);
220    if (ret < 0)
221        return ret;
222
223    avio_wb32(dyn_ctx, header);
224
225    ffio_fill(dyn_ctx, 0, mp3->xing_offset - 4);
226    ffio_wfourcc(dyn_ctx, "Xing");
227    avio_wb32(dyn_ctx, 0x01 | 0x02 | 0x04 | 0x08);  // frames / size / TOC / vbr scale
228
229    mp3->size = mpah.frame_size;
230    mp3->want=1;
231    mp3->seen=0;
232    mp3->pos=0;
233
234    avio_wb32(dyn_ctx, 0);  // frames
235    avio_wb32(dyn_ctx, 0);  // size
236
237    // TOC
238    for (i = 0; i < XING_TOC_SIZE; i++)
239        avio_w8(dyn_ctx, (uint8_t)(255 * i / XING_TOC_SIZE));
240
241    // vbr quality
242    // we write it, because some (broken) tools always expect it to be present
243    avio_wb32(dyn_ctx, 0);
244
245    // encoder short version string
246    if (enc) {
247        uint8_t encoder_str[9] = { 0 };
248        if (   strlen(enc->value) > sizeof(encoder_str)
249            && !strcmp("Lavc libmp3lame", enc->value)) {
250            memcpy(encoder_str, "Lavf lame", 9);
251        } else
252            memcpy(encoder_str, enc->value, FFMIN(strlen(enc->value), sizeof(encoder_str)));
253
254        avio_write(dyn_ctx, encoder_str, sizeof(encoder_str));
255    } else
256        avio_write(dyn_ctx, "Lavf\0\0\0\0\0", 9);
257
258    avio_w8(dyn_ctx, 0);      // tag revision 0 / unknown vbr method
259    avio_w8(dyn_ctx, 0);      // unknown lowpass filter value
260    ffio_fill(dyn_ctx, 0, 8); // empty replaygain fields
261    avio_w8(dyn_ctx, 0);      // unknown encoding flags
262    avio_w8(dyn_ctx, 0);      // unknown abr/minimal bitrate
263    avio_wb24(dyn_ctx, 0);    // empty encoder delay/padding
264
265    avio_w8(dyn_ctx,   0); // misc
266    avio_w8(dyn_ctx,   0); // mp3gain
267    avio_wb16(dyn_ctx, 0); // preset
268
269    // audio length and CRCs (will be updated later)
270    avio_wb32(dyn_ctx, 0); // music length
271    avio_wb16(dyn_ctx, 0); // music crc
272    avio_wb16(dyn_ctx, 0); // tag crc
273
274    ffio_fill(dyn_ctx, 0, mpah.frame_size - bytes_needed);
275
276    mp3->xing_frame_size   = avio_close_dyn_buf(dyn_ctx, &mp3->xing_frame);
277    mp3->xing_frame_offset = avio_tell(s->pb);
278    avio_write(s->pb, mp3->xing_frame, mp3->xing_frame_size);
279
280    mp3->audio_size = mp3->xing_frame_size;
281
282    return 0;
283}
284
285/*
286 * Add a frame to XING data.
287 * Following lame's "VbrTag.c".
288 */
289static void mp3_xing_add_frame(MP3Context *mp3, AVPacket *pkt)
290{
291    int i;
292
293    mp3->frames++;
294    mp3->seen++;
295    mp3->size += pkt->size;
296
297    if (mp3->want == mp3->seen) {
298        mp3->bag[mp3->pos] = mp3->size;
299
300        if (XING_NUM_BAGS == ++mp3->pos) {
301            /* shrink table to half size by throwing away each second bag. */
302            for (i = 1; i < XING_NUM_BAGS; i += 2)
303                mp3->bag[i >> 1] = mp3->bag[i];
304
305            /* double wanted amount per bag. */
306            mp3->want *= 2;
307            /* adjust current position to half of table size. */
308            mp3->pos = XING_NUM_BAGS / 2;
309        }
310
311        mp3->seen = 0;
312    }
313}
314
315static int mp3_write_audio_packet(AVFormatContext *s, AVPacket *pkt)
316{
317    MP3Context  *mp3 = s->priv_data;
318
319    if (pkt->data && pkt->size >= 4) {
320        MPADecodeHeader mpah;
321        int ret;
322        int av_unused base;
323        uint32_t h;
324
325        h = AV_RB32(pkt->data);
326        ret = avpriv_mpegaudio_decode_header(&mpah, h);
327        if (ret >= 0) {
328            if (!mp3->initial_bitrate)
329                mp3->initial_bitrate = mpah.bit_rate;
330            if ((mpah.bit_rate == 0) || (mp3->initial_bitrate != mpah.bit_rate))
331                mp3->has_variable_bitrate = 1;
332        } else {
333            av_log(s, AV_LOG_WARNING, "Audio packet of size %d (starting with %08"PRIX32"...) "
334                   "is invalid, writing it anyway.\n", pkt->size, h);
335        }
336
337#ifdef FILTER_VBR_HEADERS
338        /* filter out XING and INFO headers. */
339        base = 4 + xing_offtbl[mpah.lsf == 1][mpah.nb_channels == 1];
340
341        if (base + 4 <= pkt->size) {
342            uint32_t v = AV_RB32(pkt->data + base);
343
344            if (MKBETAG('X','i','n','g') == v || MKBETAG('I','n','f','o') == v)
345                return 0;
346        }
347
348        /* filter out VBRI headers. */
349        base = 4 + 32;
350
351        if (base + 4 <= pkt->size && MKBETAG('V','B','R','I') == AV_RB32(pkt->data + base))
352            return 0;
353#endif
354
355        if (mp3->xing_offset) {
356            uint8_t *side_data = NULL;
357            int side_data_size = 0;
358
359            mp3_xing_add_frame(mp3, pkt);
360            mp3->audio_size += pkt->size;
361            mp3->audio_crc   = av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE),
362                                      mp3->audio_crc, pkt->data, pkt->size);
363
364            side_data = av_packet_get_side_data(pkt,
365                                                AV_PKT_DATA_SKIP_SAMPLES,
366                                                &side_data_size);
367            if (side_data && side_data_size >= 10) {
368                mp3->padding = FFMAX(AV_RL32(side_data + 4) + 528 + 1, 0);
369                if (!mp3->delay)
370                    mp3->delay =  FFMAX(AV_RL32(side_data) - 528 - 1, 0);
371            } else {
372                mp3->padding = 0;
373            }
374        }
375    }
376
377    return ff_raw_write_packet(s, pkt);
378}
379
380static int mp3_queue_flush(AVFormatContext *s)
381{
382    MP3Context *mp3 = s->priv_data;
383    AVPacket pkt;
384    int ret = 0, write = 1;
385
386    ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
387    mp3_write_xing(s);
388
389    while (mp3->queue) {
390        ff_packet_list_get(&mp3->queue, &mp3->queue_end, &pkt);
391        if (write && (ret = mp3_write_audio_packet(s, &pkt)) < 0)
392            write = 0;
393        av_packet_unref(&pkt);
394    }
395    return ret;
396}
397
398static void mp3_update_xing(AVFormatContext *s)
399{
400    MP3Context  *mp3 = s->priv_data;
401    AVReplayGain *rg;
402    uint16_t tag_crc;
403    uint8_t *toc;
404    int i, rg_size;
405    int64_t old_pos = avio_tell(s->pb);
406
407    /* replace "Xing" identification string with "Info" for CBR files. */
408    if (!mp3->has_variable_bitrate)
409        AV_WL32(mp3->xing_frame + mp3->xing_offset, MKTAG('I', 'n', 'f', 'o'));
410
411    AV_WB32(mp3->xing_frame + mp3->xing_offset + 8,  mp3->frames);
412    AV_WB32(mp3->xing_frame + mp3->xing_offset + 12, mp3->size);
413
414    toc    = mp3->xing_frame + mp3->xing_offset + 16;
415    toc[0] = 0;  // first toc entry has to be zero.
416    for (i = 1; i < XING_TOC_SIZE; ++i) {
417        int j = i * mp3->pos / XING_TOC_SIZE;
418        int seek_point = 256LL * mp3->bag[j] / mp3->size;
419        toc[i] = FFMIN(seek_point, 255);
420    }
421
422    /* write replaygain */
423    rg = (AVReplayGain*)av_stream_get_side_data(s->streams[0], AV_PKT_DATA_REPLAYGAIN,
424                                                &rg_size);
425    if (rg && rg_size >= sizeof(*rg)) {
426        uint16_t val;
427
428        AV_WB32(mp3->xing_frame + mp3->xing_offset + 131,
429                av_rescale(rg->track_peak, 1 << 23, 100000));
430
431        if (rg->track_gain != INT32_MIN) {
432            val  = FFABS(rg->track_gain / 10000) & ((1 << 9) - 1);
433            val |= (rg->track_gain < 0) << 9;
434            val |= 1 << 13;
435            AV_WB16(mp3->xing_frame + mp3->xing_offset + 135, val);
436        }
437
438        if (rg->album_gain != INT32_MIN) {
439            val  = FFABS(rg->album_gain / 10000) & ((1 << 9) - 1);
440            val |= (rg->album_gain < 0) << 9;
441            val |= 1 << 14;
442            AV_WB16(mp3->xing_frame + mp3->xing_offset + 137, val);
443        }
444    }
445
446    /* write encoder delay/padding */
447    if (mp3->delay >= 1 << 12) {
448        mp3->delay = (1 << 12) - 1;
449        av_log(s, AV_LOG_WARNING, "Too many samples of initial padding.\n");
450    }
451    if (mp3->padding >= 1 << 12) {
452        mp3->padding = (1 << 12) - 1;
453        av_log(s, AV_LOG_WARNING, "Too many samples of trailing padding.\n");
454    }
455    AV_WB24(mp3->xing_frame + mp3->xing_offset + 141, (mp3->delay << 12) + mp3->padding);
456
457    AV_WB32(mp3->xing_frame + mp3->xing_offset + XING_SIZE - 8, mp3->audio_size);
458    AV_WB16(mp3->xing_frame + mp3->xing_offset + XING_SIZE - 4, mp3->audio_crc);
459
460    tag_crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE), 0, mp3->xing_frame, 190);
461    AV_WB16(mp3->xing_frame + mp3->xing_offset + XING_SIZE - 2, tag_crc);
462
463    avio_seek(s->pb,  mp3->xing_frame_offset, SEEK_SET);
464    avio_write(s->pb, mp3->xing_frame, mp3->xing_frame_size);
465    avio_seek(s->pb, old_pos, SEEK_SET);
466}
467
468static int mp3_write_trailer(struct AVFormatContext *s)
469{
470    uint8_t buf[ID3v1_TAG_SIZE];
471    MP3Context *mp3 = s->priv_data;
472
473    if (mp3->pics_to_write) {
474        av_log(s, AV_LOG_WARNING, "No packets were sent for some of the "
475               "attached pictures.\n");
476        mp3_queue_flush(s);
477    }
478
479    /* write the id3v1 tag */
480    if (mp3->write_id3v1 && id3v1_create_tag(s, buf) > 0) {
481        avio_write(s->pb, buf, ID3v1_TAG_SIZE);
482    }
483
484    if (mp3->xing_offset)
485        mp3_update_xing(s);
486
487    return 0;
488}
489
490static int query_codec(enum AVCodecID id, int std_compliance)
491{
492    const CodecMime *cm= ff_id3v2_mime_tags;
493    while(cm->id != AV_CODEC_ID_NONE) {
494        if(id == cm->id)
495            return MKTAG('A', 'P', 'I', 'C');
496        cm++;
497    }
498    return -1;
499}
500
501static const AVOption options[] = {
502    { "id3v2_version", "Select ID3v2 version to write. Currently 3 and 4 are supported.",
503      offsetof(MP3Context, id3v2_version), AV_OPT_TYPE_INT, {.i64 = 4}, 0, 4, AV_OPT_FLAG_ENCODING_PARAM},
504    { "write_id3v1", "Enable ID3v1 writing. ID3v1 tags are written in UTF-8 which may not be supported by most software.",
505      offsetof(MP3Context, write_id3v1), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
506    { "write_xing",  "Write the Xing header containing file duration.",
507      offsetof(MP3Context, write_xing),  AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
508    { NULL },
509};
510
511static const AVClass mp3_muxer_class = {
512    .class_name     = "MP3 muxer",
513    .item_name      = av_default_item_name,
514    .option         = options,
515    .version        = LIBAVUTIL_VERSION_INT,
516};
517
518static int mp3_write_packet(AVFormatContext *s, AVPacket *pkt)
519{
520    MP3Context *mp3 = s->priv_data;
521
522    if (pkt->stream_index == mp3->audio_stream_idx) {
523        if (mp3->pics_to_write) {
524            /* buffer audio packets until we get all the pictures */
525            int ret = ff_packet_list_put(&mp3->queue, &mp3->queue_end, pkt, FF_PACKETLIST_FLAG_REF_PACKET);
526
527            if (ret < 0) {
528                av_log(s, AV_LOG_WARNING, "Not enough memory to buffer audio. Skipping picture streams\n");
529                mp3->pics_to_write = 0;
530                mp3_queue_flush(s);
531                return mp3_write_audio_packet(s, pkt);
532            }
533        } else
534            return mp3_write_audio_packet(s, pkt);
535    } else {
536        int ret;
537
538        /* warn only once for each stream */
539        if (s->streams[pkt->stream_index]->nb_frames == 1) {
540            av_log(s, AV_LOG_WARNING, "Got more than one picture in stream %d,"
541                   " ignoring.\n", pkt->stream_index);
542        }
543        if (!mp3->pics_to_write || s->streams[pkt->stream_index]->nb_frames >= 1)
544            return 0;
545
546        if ((ret = ff_id3v2_write_apic(s, &mp3->id3, pkt)) < 0)
547            return ret;
548        mp3->pics_to_write--;
549
550        /* flush the buffered audio packets */
551        if (!mp3->pics_to_write &&
552            (ret = mp3_queue_flush(s)) < 0)
553            return ret;
554    }
555
556    return 0;
557}
558
559/**
560 * Write an ID3v2 header at beginning of stream
561 */
562
563static int mp3_init(struct AVFormatContext *s)
564{
565    MP3Context  *mp3 = s->priv_data;
566    int i;
567
568    if (mp3->id3v2_version      &&
569        mp3->id3v2_version != 3 &&
570        mp3->id3v2_version != 4) {
571        av_log(s, AV_LOG_ERROR, "Invalid ID3v2 version requested: %d. Only "
572               "3, 4 or 0 (disabled) are allowed.\n", mp3->id3v2_version);
573        return AVERROR(EINVAL);
574    }
575
576    /* check the streams -- we want exactly one audio and arbitrary number of
577     * video (attached pictures) */
578    mp3->audio_stream_idx = -1;
579    for (i = 0; i < s->nb_streams; i++) {
580        AVStream *st = s->streams[i];
581        if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
582            if (mp3->audio_stream_idx >= 0 || st->codecpar->codec_id != AV_CODEC_ID_MP3) {
583                av_log(s, AV_LOG_ERROR, "Invalid audio stream. Exactly one MP3 "
584                       "audio stream is required.\n");
585                return AVERROR(EINVAL);
586            }
587            mp3->audio_stream_idx = i;
588        } else if (st->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
589            av_log(s, AV_LOG_ERROR, "Only audio streams and pictures are allowed in MP3.\n");
590            return AVERROR(EINVAL);
591        }
592    }
593    if (mp3->audio_stream_idx < 0) {
594        av_log(s, AV_LOG_ERROR, "No audio stream present.\n");
595        return AVERROR(EINVAL);
596    }
597    mp3->pics_to_write = s->nb_streams - 1;
598
599    if (mp3->pics_to_write && !mp3->id3v2_version) {
600        av_log(s, AV_LOG_ERROR, "Attached pictures were requested, but the "
601               "ID3v2 header is disabled.\n");
602        return AVERROR(EINVAL);
603    }
604
605    return 0;
606}
607
608static int mp3_write_header(struct AVFormatContext *s)
609{
610    MP3Context  *mp3 = s->priv_data;
611    int ret;
612
613    if (mp3->id3v2_version) {
614        ff_id3v2_start(&mp3->id3, s->pb, mp3->id3v2_version, ID3v2_DEFAULT_MAGIC);
615        ret = ff_id3v2_write_metadata(s, &mp3->id3);
616        if (ret < 0)
617            return ret;
618    }
619
620    if (!mp3->pics_to_write) {
621        if (mp3->id3v2_version)
622            ff_id3v2_finish(&mp3->id3, s->pb, s->metadata_header_padding);
623        mp3_write_xing(s);
624    }
625
626    return 0;
627}
628
629static void mp3_deinit(struct AVFormatContext *s)
630{
631    MP3Context *mp3 = s->priv_data;
632
633    ff_packet_list_free(&mp3->queue, &mp3->queue_end);
634    av_freep(&mp3->xing_frame);
635}
636
637AVOutputFormat ff_mp3_muxer = {
638    .name              = "mp3",
639    .long_name         = NULL_IF_CONFIG_SMALL("MP3 (MPEG audio layer 3)"),
640    .mime_type         = "audio/mpeg",
641    .extensions        = "mp3",
642    .priv_data_size    = sizeof(MP3Context),
643    .audio_codec       = AV_CODEC_ID_MP3,
644    .video_codec       = AV_CODEC_ID_PNG,
645    .init              = mp3_init,
646    .write_header      = mp3_write_header,
647    .write_packet      = mp3_write_packet,
648    .write_trailer     = mp3_write_trailer,
649    .deinit            = mp3_deinit,
650    .query_codec       = query_codec,
651    .flags             = AVFMT_NOTIMESTAMPS,
652    .priv_class        = &mp3_muxer_class,
653};