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ffmpeg / libavformat / matroskaenc.c @ a23c9c4a

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1
/*
2
 * Matroska muxer
3
 * Copyright (c) 2007 David Conrad
4
 *
5
 * This file is part of FFmpeg.
6
 *
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 * 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
 *
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 * 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
 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21

    
22
#include "avformat.h"
23
#include "md5.h"
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#include "riff.h"
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#include "xiph.h"
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#include "matroska.h"
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#include "avc.h"
28

    
29
typedef struct ebml_master {
30
    offset_t        pos;                ///< absolute offset in the file where the master's elements start
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    int             sizebytes;          ///< how many bytes were reserved for the size
32
} ebml_master;
33

    
34
typedef struct mkv_seekhead_entry {
35
    unsigned int    elementid;
36
    uint64_t        segmentpos;
37
} mkv_seekhead_entry;
38

    
39
typedef struct mkv_seekhead {
40
    offset_t                filepos;
41
    offset_t                segment_offset;     ///< the file offset to the beginning of the segment
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    int                     reserved_size;      ///< -1 if appending to file
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    int                     max_entries;
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    mkv_seekhead_entry      *entries;
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    int                     num_entries;
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} mkv_seekhead;
47

    
48
typedef struct {
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    uint64_t        pts;
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    int             tracknum;
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    offset_t        cluster_pos;        ///< file offset of the cluster containing the block
52
} mkv_cuepoint;
53

    
54
typedef struct {
55
    offset_t        segment_offset;
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    mkv_cuepoint    *entries;
57
    int             num_entries;
58
} mkv_cues;
59

    
60
typedef struct MatroskaMuxContext {
61
    ebml_master     segment;
62
    offset_t        segment_offset;
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    offset_t        segment_uid;
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    ebml_master     cluster;
65
    offset_t        cluster_pos;        ///< file offset of the current cluster
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    uint64_t        cluster_pts;
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    offset_t        duration_offset;
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    uint64_t        duration;
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    mkv_seekhead    *main_seekhead;
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    mkv_seekhead    *cluster_seekhead;
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    mkv_cues        *cues;
72

    
73
    struct AVMD5    *md5_ctx;
74
} MatroskaMuxContext;
75

    
76

    
77
/** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
78
 * offset, 4 bytes for target EBML ID */
79
#define MAX_SEEKENTRY_SIZE 21
80

    
81
/** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
82
 * 8-byte uint max */
83
#define MAX_CUETRACKPOS_SIZE 22
84

    
85
/** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
86
#define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
87

    
88

    
89
static int ebml_id_size(unsigned int id)
90
{
91
    return (av_log2(id+1)-1)/7+1;
92
}
93

    
94
static void put_ebml_id(ByteIOContext *pb, unsigned int id)
95
{
96
    int i = ebml_id_size(id);
97
    while (i--)
98
        put_byte(pb, id >> (i*8));
99
}
100

    
101
/**
102
 * Write an EBML size meaning "unknown size".
103
 *
104
 * @param bytes The number of bytes the size should occupy (maximum: 8).
105
 */
106
static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
107
{
108
    assert(bytes <= 8);
109
    put_byte(pb, 0x1ff >> bytes);
110
    while (--bytes)
111
        put_byte(pb, 0xff);
112
}
113

    
114
/**
115
 * Calculate how many bytes are needed to represent a given number in EBML.
116
 */
117
static int ebml_num_size(uint64_t num)
118
{
119
    int bytes = 1;
120
    while ((num+1) >> bytes*7) bytes++;
121
    return bytes;
122
}
123

    
124
/**
125
 * Write a number in EBML variable length format.
126
 *
127
 * @param bytes The number of bytes that need to be used to write the number.
128
 *              If zero, any number of bytes can be used.
129
 */
130
static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
131
{
132
    int i, needed_bytes = ebml_num_size(num);
133

    
134
    // sizes larger than this are currently undefined in EBML
135
    assert(num < (1ULL<<56)-1);
136

    
137
    if (bytes == 0)
138
        // don't care how many bytes are used, so use the min
139
        bytes = needed_bytes;
140
    // the bytes needed to write the given size would exceed the bytes
141
    // that we need to use, so write unknown size. This shouldn't happen.
142
    assert(bytes >= needed_bytes);
143

    
144
    num |= 1ULL << bytes*7;
145
    for (i = bytes - 1; i >= 0; i--)
146
        put_byte(pb, num >> i*8);
147
}
148

    
149
static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
150
{
151
    int i, bytes = 1;
152
    while (val >> bytes*8) bytes++;
153

    
154
    put_ebml_id(pb, elementid);
155
    put_ebml_num(pb, bytes, 0);
156
    for (i = bytes - 1; i >= 0; i--)
157
        put_byte(pb, val >> i*8);
158
}
159

    
160
static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
161
{
162
    put_ebml_id(pb, elementid);
163
    put_ebml_num(pb, 8, 0);
164
    put_be64(pb, av_dbl2int(val));
165
}
166

    
167
static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
168
                            const uint8_t *buf, int size)
169
{
170
    put_ebml_id(pb, elementid);
171
    put_ebml_num(pb, size, 0);
172
    put_buffer(pb, buf, size);
173
}
174

    
175
static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
176
{
177
    put_ebml_binary(pb, elementid, str, strlen(str));
178
}
179

    
180
/**
181
 * Writes a void element of a given size. Useful for reserving space in
182
 * the file to be written to later.
183
 *
184
 * @param size The number of bytes to reserve, which must be at least 2.
185
 */
186
static void put_ebml_void(ByteIOContext *pb, uint64_t size)
187
{
188
    offset_t currentpos = url_ftell(pb);
189

    
190
    assert(size >= 2);
191

    
192
    put_ebml_id(pb, EBML_ID_VOID);
193
    // we need to subtract the length needed to store the size from the
194
    // size we need to reserve so 2 cases, we use 8 bytes to store the
195
    // size if possible, 1 byte otherwise
196
    if (size < 10)
197
        put_ebml_num(pb, size-1, 0);
198
    else
199
        put_ebml_num(pb, size-9, 8);
200
    while(url_ftell(pb) < currentpos + size)
201
        put_byte(pb, 0);
202
}
203

    
204
static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
205
{
206
    int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
207
    put_ebml_id(pb, elementid);
208
    put_ebml_size_unknown(pb, bytes);
209
    return (ebml_master){ url_ftell(pb), bytes };
210
}
211

    
212
static void end_ebml_master(ByteIOContext *pb, ebml_master master)
213
{
214
    offset_t pos = url_ftell(pb);
215

    
216
    // leave the unknown size for masters when streaming
217
    if (url_is_streamed(pb))
218
        return;
219

    
220
    url_fseek(pb, master.pos - master.sizebytes, SEEK_SET);
221
    put_ebml_num(pb, pos - master.pos, master.sizebytes);
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    url_fseek(pb, pos, SEEK_SET);
223
}
224

    
225
static void put_xiph_size(ByteIOContext *pb, int size)
226
{
227
    int i;
228
    for (i = 0; i < size / 255; i++)
229
        put_byte(pb, 255);
230
    put_byte(pb, size % 255);
231
}
232

    
233
/**
234
 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
235
 * elements. If a maximum number of elements is specified, enough space
236
 * will be reserved at the current file location to write a seek head of
237
 * that size.
238
 *
239
 * @param segment_offset The absolute offset to the position in the file
240
 *                       where the segment begins.
241
 * @param numelements The maximum number of elements that will be indexed
242
 *                    by this seek head, 0 if unlimited.
243
 */
244
static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
245
{
246
    mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
247
    if (new_seekhead == NULL)
248
        return NULL;
249

    
250
    new_seekhead->segment_offset = segment_offset;
251

    
252
    if (numelements > 0) {
253
        new_seekhead->filepos = url_ftell(pb);
254
        // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
255
        // and size, and 3 bytes to guarantee that an EBML void element
256
        // will fit afterwards
257
        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
258
        new_seekhead->max_entries = numelements;
259
        put_ebml_void(pb, new_seekhead->reserved_size);
260
    }
261
    return new_seekhead;
262
}
263

    
264
static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
265
{
266
    mkv_seekhead_entry *entries = seekhead->entries;
267

    
268
    // don't store more elements than we reserved space for
269
    if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
270
        return -1;
271

    
272
    entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
273
    if (entries == NULL)
274
        return AVERROR(ENOMEM);
275

    
276
    entries[seekhead->num_entries  ].elementid = elementid;
277
    entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
278

    
279
    seekhead->entries = entries;
280
    return 0;
281
}
282

    
283
/**
284
 * Write the seek head to the file and free it. If a maximum number of
285
 * elements was specified to mkv_start_seekhead(), the seek head will
286
 * be written at the location reserved for it. Otherwise, it is written
287
 * at the current location in the file.
288
 *
289
 * @return The file offset where the seekhead was written.
290
 */
291
static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
292
{
293
    ebml_master metaseek, seekentry;
294
    offset_t currentpos;
295
    int i;
296

    
297
    currentpos = url_ftell(pb);
298

    
299
    if (seekhead->reserved_size > 0)
300
        url_fseek(pb, seekhead->filepos, SEEK_SET);
301

    
302
    metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
303
    for (i = 0; i < seekhead->num_entries; i++) {
304
        mkv_seekhead_entry *entry = &seekhead->entries[i];
305

    
306
        seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
307

    
308
        put_ebml_id(pb, MATROSKA_ID_SEEKID);
309
        put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
310
        put_ebml_id(pb, entry->elementid);
311

    
312
        put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
313
        end_ebml_master(pb, seekentry);
314
    }
315
    end_ebml_master(pb, metaseek);
316

    
317
    if (seekhead->reserved_size > 0) {
318
        uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
319
        put_ebml_void(pb, remaining);
320
        url_fseek(pb, currentpos, SEEK_SET);
321

    
322
        currentpos = seekhead->filepos;
323
    }
324
    av_free(seekhead->entries);
325
    av_free(seekhead);
326

    
327
    return currentpos;
328
}
329

    
330
static mkv_cues * mkv_start_cues(offset_t segment_offset)
331
{
332
    mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
333
    if (cues == NULL)
334
        return NULL;
335

    
336
    cues->segment_offset = segment_offset;
337
    return cues;
338
}
339

    
340
static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, offset_t cluster_pos)
341
{
342
    mkv_cuepoint *entries = cues->entries;
343

    
344
    entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
345
    if (entries == NULL)
346
        return AVERROR(ENOMEM);
347

    
348
    entries[cues->num_entries  ].pts = pkt->pts;
349
    entries[cues->num_entries  ].tracknum = pkt->stream_index + 1;
350
    entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
351

    
352
    cues->entries = entries;
353
    return 0;
354
}
355

    
356
static offset_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
357
{
358
    ebml_master cues_element;
359
    offset_t currentpos;
360
    int i, j;
361

    
362
    currentpos = url_ftell(pb);
363
    cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
364

    
365
    for (i = 0; i < cues->num_entries; i++) {
366
        ebml_master cuepoint, track_positions;
367
        mkv_cuepoint *entry = &cues->entries[i];
368
        uint64_t pts = entry->pts;
369

    
370
        cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
371
        put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
372

    
373
        // put all the entries from different tracks that have the exact same
374
        // timestamp into the same CuePoint
375
        for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
376
            track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
377
            put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
378
            put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
379
            end_ebml_master(pb, track_positions);
380
        }
381
        i += j - 1;
382
        end_ebml_master(pb, cuepoint);
383
    }
384
    end_ebml_master(pb, cues_element);
385

    
386
    av_free(cues->entries);
387
    av_free(cues);
388
    return currentpos;
389
}
390

    
391
static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
392
{
393
    uint8_t *header_start[3];
394
    int header_len[3];
395
    int first_header_size;
396
    int j;
397

    
398
    if (codec->codec_id == CODEC_ID_VORBIS)
399
        first_header_size = 30;
400
    else
401
        first_header_size = 42;
402

    
403
    if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
404
                              first_header_size, header_start, header_len) < 0) {
405
        av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
406
        return -1;
407
    }
408

    
409
    put_byte(pb, 2);                    // number packets - 1
410
    for (j = 0; j < 2; j++) {
411
        put_xiph_size(pb, header_len[j]);
412
    }
413
    for (j = 0; j < 3; j++)
414
        put_buffer(pb, header_start[j], header_len[j]);
415

    
416
    return 0;
417
}
418

    
419
#define FLAC_STREAMINFO_SIZE 34
420

    
421
static int put_flac_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
422
{
423
    // if the extradata_size is greater than FLAC_STREAMINFO_SIZE,
424
    // assume that it's in Matroska's format already
425
    if (codec->extradata_size < FLAC_STREAMINFO_SIZE) {
426
        av_log(s, AV_LOG_ERROR, "Invalid FLAC extradata\n");
427
        return -1;
428
    } else if (codec->extradata_size == FLAC_STREAMINFO_SIZE) {
429
        // only the streaminfo packet
430
        put_byte(pb, 0);
431
        put_xiph_size(pb, codec->extradata_size);
432
        av_log(s, AV_LOG_ERROR, "Only one packet\n");
433
    }
434
    put_buffer(pb, codec->extradata, codec->extradata_size);
435
    return 0;
436
}
437

    
438
static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
439
{
440
    static const int aac_sample_rates[] = {
441
        96000, 88200, 64000, 48000, 44100, 32000,
442
        24000, 22050, 16000, 12000, 11025,  8000,
443
    };
444
    int sri;
445

    
446
    if (codec->extradata_size < 2) {
447
        av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
448
        return;
449
    }
450

    
451
    sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
452
    if (sri > 12) {
453
        av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
454
        return;
455
    }
456
    *sample_rate = aac_sample_rates[sri];
457

    
458
    // if sbr, get output sample rate as well
459
    if (codec->extradata_size == 5) {
460
        sri = (codec->extradata[4] >> 3) & 0xF;
461
        if (sri > 12) {
462
            av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
463
            return;
464
        }
465
        *output_sample_rate = aac_sample_rates[sri];
466
    }
467
}
468

    
469
static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id)
470
{
471
    ByteIOContext *dyn_cp;
472
    uint8_t *codecpriv;
473
    int ret, codecpriv_size;
474

    
475
    ret = url_open_dyn_buf(&dyn_cp);
476
    if(ret < 0)
477
        return ret;
478

    
479
    if (native_id) {
480
        if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
481
            ret = put_xiph_codecpriv(s, dyn_cp, codec);
482
        else if (codec->codec_id == CODEC_ID_FLAC)
483
            ret = put_flac_codecpriv(s, dyn_cp, codec);
484
        else if (codec->codec_id == CODEC_ID_H264)
485
            ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
486
        else if (codec->extradata_size)
487
            put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
488
    } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
489
        if (!codec->codec_tag)
490
            codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
491
        if (!codec->codec_tag) {
492
            av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
493
            ret = -1;
494
        }
495

    
496
        put_bmp_header(dyn_cp, codec, codec_bmp_tags, 0);
497

    
498
    } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
499
        if (!codec->codec_tag)
500
            codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
501
        if (!codec->codec_tag) {
502
            av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
503
            ret = -1;
504
        }
505

    
506
        put_wav_header(dyn_cp, codec);
507
    }
508

    
509
    codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
510
    if (codecpriv_size)
511
        put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
512
    av_free(codecpriv);
513
    return ret;
514
}
515

    
516
static int mkv_write_tracks(AVFormatContext *s)
517
{
518
    MatroskaMuxContext *mkv = s->priv_data;
519
    ByteIOContext *pb = s->pb;
520
    ebml_master tracks;
521
    int i, j, ret;
522

    
523
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
524
    if (ret < 0) return ret;
525

    
526
    tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
527
    for (i = 0; i < s->nb_streams; i++) {
528
        AVStream *st = s->streams[i];
529
        AVCodecContext *codec = st->codec;
530
        ebml_master subinfo, track;
531
        int native_id = 0;
532
        int bit_depth = av_get_bits_per_sample(codec->codec_id);
533
        int sample_rate = codec->sample_rate;
534
        int output_sample_rate = 0;
535

    
536
        if (!bit_depth)
537
            bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
538

    
539
        if (codec->codec_id == CODEC_ID_AAC)
540
            get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
541

    
542
        track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
543
        put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
544
        put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
545
        put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
546

    
547
        if (st->language[0])
548
            put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
549
        else
550
            put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, "und");
551

    
552
        // look for a codec ID string specific to mkv to use,
553
        // if none are found, use AVI codes
554
        for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
555
            if (ff_mkv_codec_tags[j].id == codec->codec_id) {
556
                put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
557
                native_id = 1;
558
                break;
559
            }
560
        }
561

    
562
        switch (codec->codec_type) {
563
            case CODEC_TYPE_VIDEO:
564
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
565

    
566
                if (!native_id)
567
                    // if there is no mkv-specific codec ID, use VFW mode
568
                    put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
569

    
570
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
571
                // XXX: interlace flag?
572
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
573
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
574
                if (codec->sample_aspect_ratio.num) {
575
                    AVRational dar = av_mul_q(codec->sample_aspect_ratio,
576
                                    (AVRational){codec->width, codec->height});
577
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , dar.num);
578
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, dar.den);
579
                }
580
                end_ebml_master(pb, subinfo);
581
                break;
582

    
583
            case CODEC_TYPE_AUDIO:
584
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
585

    
586
                if (!native_id)
587
                    // no mkv-specific ID, use ACM mode
588
                    put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_AUDIO_ACM);
589

    
590
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
591
                put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
592
                put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
593
                if (output_sample_rate)
594
                    put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
595
                if (bit_depth)
596
                    put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
597
                end_ebml_master(pb, subinfo);
598
                break;
599

    
600
            case CODEC_TYPE_SUBTITLE:
601
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
602
                break;
603
            default:
604
                av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
605
                break;
606
        }
607
        ret = mkv_write_codecprivate(s, pb, codec, native_id);
608
        if (ret < 0) return ret;
609

    
610
        end_ebml_master(pb, track);
611

    
612
        // ms precision is the de-facto standard timescale for mkv files
613
        av_set_pts_info(st, 64, 1, 1000);
614
    }
615
    end_ebml_master(pb, tracks);
616
    return 0;
617
}
618

    
619
static int mkv_write_header(AVFormatContext *s)
620
{
621
    MatroskaMuxContext *mkv = s->priv_data;
622
    ByteIOContext *pb = s->pb;
623
    ebml_master ebml_header, segment_info;
624
    int ret;
625

    
626
    mkv->md5_ctx = av_mallocz(av_md5_size);
627
    av_md5_init(mkv->md5_ctx);
628

    
629
    ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
630
    put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
631
    put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
632
    put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
633
    put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
634
    put_ebml_string (pb, EBML_ID_DOCTYPE            ,  "matroska");
635
    put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
636
    put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
637
    end_ebml_master(pb, ebml_header);
638

    
639
    mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
640
    mkv->segment_offset = url_ftell(pb);
641

    
642
    // we write 2 seek heads - one at the end of the file to point to each
643
    // cluster, and one at the beginning to point to all other level one
644
    // elements (including the seek head at the end of the file), which
645
    // isn't more than 10 elements if we only write one of each other
646
    // currently defined level 1 element
647
    mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
648
    mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
649
    if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
650
        return AVERROR(ENOMEM);
651

    
652
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
653
    if (ret < 0) return ret;
654

    
655
    segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
656
    put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
657
    if (strlen(s->title))
658
        put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
659
    if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
660
        put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
661
        put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
662

    
663
        // reserve space to write the segment UID later
664
        mkv->segment_uid = url_ftell(pb);
665
        put_ebml_void(pb, 19);
666
    }
667

    
668
    // reserve space for the duration
669
    mkv->duration = 0;
670
    mkv->duration_offset = url_ftell(pb);
671
    put_ebml_void(pb, 11);                  // assumes double-precision float to be written
672
    end_ebml_master(pb, segment_info);
673

    
674
    ret = mkv_write_tracks(s);
675
    if (ret < 0) return ret;
676

    
677
    ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
678
    if (ret < 0) return ret;
679

    
680
    mkv->cluster_pos = url_ftell(pb);
681
    mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
682
    put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
683
    mkv->cluster_pts = 0;
684

    
685
    mkv->cues = mkv_start_cues(mkv->segment_offset);
686
    if (mkv->cues == NULL)
687
        return AVERROR(ENOMEM);
688

    
689
    return 0;
690
}
691

    
692
static int mkv_block_size(AVPacket *pkt)
693
{
694
    int size = 4;           // track num + timecode + flags
695
    return size + pkt->size;
696
}
697

    
698
static int mkv_blockgroup_size(AVPacket *pkt)
699
{
700
    int size = mkv_block_size(pkt);
701
    size += ebml_num_size(size);
702
    size += 2;              // EBML ID for block and block duration
703
    size += 8;              // max size of block duration
704
    size += ebml_num_size(size);
705
    size += 1;              // blockgroup EBML ID
706
    return size;
707
}
708

    
709
static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
710
{
711
    MatroskaMuxContext *mkv = s->priv_data;
712
    ByteIOContext *pb = s->pb;
713

    
714
    av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
715
           "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
716
           url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
717
    put_ebml_id(pb, blockid);
718
    put_ebml_num(pb, mkv_block_size(pkt), 0);
719
    put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
720
    put_be16(pb, pkt->pts - mkv->cluster_pts);
721
    put_byte(pb, flags);
722
    put_buffer(pb, pkt->data, pkt->size);
723
}
724

    
725
static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
726
{
727
    MatroskaMuxContext *mkv = s->priv_data;
728
    ByteIOContext *pb = s->pb;
729
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
730
    int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
731
    int ret;
732

    
733
    // start a new cluster every 5 MB or 5 sec
734
    if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
735
        av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
736
               " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
737
        end_ebml_master(pb, mkv->cluster);
738

    
739
        ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
740
        if (ret < 0) return ret;
741

    
742
        mkv->cluster_pos = url_ftell(pb);
743
        mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
744
        put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
745
        mkv->cluster_pts = pkt->pts;
746
        av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
747
    }
748

    
749
    if (codec->codec_id == CODEC_ID_H264 &&
750
        codec->extradata_size > 0 && AV_RB32(codec->extradata) == 0x00000001) {
751
        /* from x264 or from bytestream h264 */
752
        /* nal reformating needed */
753
        int ret = ff_avc_parse_nal_units(pkt->data, &pkt->data, &pkt->size);
754
        if (ret < 0)
755
            return ret;
756
        assert(pkt->size);
757
    }
758

    
759
    if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
760
        mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
761
    } else {
762
        ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt));
763
        mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
764
        put_ebml_uint(pb, MATROSKA_ID_DURATION, pkt->duration);
765
        end_ebml_master(pb, blockgroup);
766
    }
767

    
768
    if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
769
        ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
770
        if (ret < 0) return ret;
771
    }
772

    
773
    mkv->duration = FFMAX(mkv->duration, pkt->pts + pkt->duration);
774
    return 0;
775
}
776

    
777
static int mkv_write_trailer(AVFormatContext *s)
778
{
779
    MatroskaMuxContext *mkv = s->priv_data;
780
    ByteIOContext *pb = s->pb;
781
    offset_t currentpos, second_seekhead, cuespos;
782
    int ret;
783

    
784
    end_ebml_master(pb, mkv->cluster);
785

    
786
    if (!url_is_streamed(pb)) {
787
        cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
788
        second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
789

    
790
        ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
791
        if (ret < 0) return ret;
792
        ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
793
        if (ret < 0) return ret;
794
        mkv_write_seekhead(pb, mkv->main_seekhead);
795

    
796
        // update the duration
797
        av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
798
        currentpos = url_ftell(pb);
799
        url_fseek(pb, mkv->duration_offset, SEEK_SET);
800
        put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
801

    
802
        // write the md5sum of some frames as the segment UID
803
        if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
804
            uint8_t segment_uid[16];
805
            av_md5_final(mkv->md5_ctx, segment_uid);
806
            url_fseek(pb, mkv->segment_uid, SEEK_SET);
807
            put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
808
        }
809
        url_fseek(pb, currentpos, SEEK_SET);
810
    }
811

    
812
    end_ebml_master(pb, mkv->segment);
813
    av_free(mkv->md5_ctx);
814
    return 0;
815
}
816

    
817
AVOutputFormat matroska_muxer = {
818
    "matroska",
819
    "Matroska File Format",
820
    "video/x-matroska",
821
    "mkv",
822
    sizeof(MatroskaMuxContext),
823
    CODEC_ID_MP2,
824
    CODEC_ID_MPEG4,
825
    mkv_write_header,
826
    mkv_write_packet,
827
    mkv_write_trailer,
828
    .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
829
    .subtitle_codec = CODEC_ID_TEXT,
830
};
831

    
832
AVOutputFormat matroska_audio_muxer = {
833
    "matroska",
834
    "Matroska File Format",
835
    "audio/x-matroska",
836
    "mka",
837
    sizeof(MatroskaMuxContext),
838
    CODEC_ID_MP2,
839
    CODEC_ID_NONE,
840
    mkv_write_header,
841
    mkv_write_packet,
842
    mkv_write_trailer,
843
    .codec_tag = (const AVCodecTag*[]){codec_wav_tags, 0},
844
};