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ffmpeg / libavformat / matroskaenc.c @ 49bd8e4b

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1
/*
2
 * Matroska muxer
3
 * Copyright (c) 2007 David Conrad
4
 *
5
 * This file is part of FFmpeg.
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 *
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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
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 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
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 *
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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
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
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 *
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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"
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#include "riff.h"
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#include "isom.h"
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#include "matroska.h"
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#include "avc.h"
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#include "flacenc.h"
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#include "libavutil/intreadwrite.h"
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#include "libavutil/random_seed.h"
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#include "libavutil/lfg.h"
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#include "libavcodec/xiph.h"
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#include "libavcodec/mpeg4audio.h"
33

    
34
typedef struct ebml_master {
35
    int64_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
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} ebml_master;
38

    
39
typedef struct mkv_seekhead_entry {
40
    unsigned int    elementid;
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    uint64_t        segmentpos;
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} mkv_seekhead_entry;
43

    
44
typedef struct mkv_seekhead {
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    int64_t                 filepos;
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    int64_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;
52

    
53
typedef struct {
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    uint64_t        pts;
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    int             tracknum;
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    int64_t         cluster_pos;        ///< file offset of the cluster containing the block
57
} mkv_cuepoint;
58

    
59
typedef struct {
60
    int64_t         segment_offset;
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    mkv_cuepoint    *entries;
62
    int             num_entries;
63
} mkv_cues;
64

    
65
typedef struct {
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    int             write_dts;
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} mkv_track;
68

    
69
#define MODE_MATROSKAv2 0x01
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#define MODE_WEBM       0x02
71

    
72
typedef struct MatroskaMuxContext {
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    int             mode;
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    ByteIOContext   *dyn_bc;
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    ebml_master     segment;
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    int64_t         segment_offset;
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    ebml_master     cluster;
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    int64_t         cluster_pos;        ///< file offset of the current cluster
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    int64_t         cluster_pts;
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    int64_t         duration_offset;
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    int64_t         duration;
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    mkv_seekhead    *main_seekhead;
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    mkv_cues        *cues;
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    mkv_track       *tracks;
85

    
86
    unsigned int    audio_buffer_size;
87
    AVPacket        cur_audio_pkt;
88
} MatroskaMuxContext;
89

    
90

    
91
/** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
92
 * offset, 4 bytes for target EBML ID */
93
#define MAX_SEEKENTRY_SIZE 21
94

    
95
/** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
96
 * 8-byte uint max */
97
#define MAX_CUETRACKPOS_SIZE 22
98

    
99
/** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
100
#define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
101

    
102

    
103
static int ebml_id_size(unsigned int id)
104
{
105
    return (av_log2(id+1)-1)/7+1;
106
}
107

    
108
static void put_ebml_id(ByteIOContext *pb, unsigned int id)
109
{
110
    int i = ebml_id_size(id);
111
    while (i--)
112
        put_byte(pb, id >> (i*8));
113
}
114

    
115
/**
116
 * Write an EBML size meaning "unknown size".
117
 *
118
 * @param bytes The number of bytes the size should occupy (maximum: 8).
119
 */
120
static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
121
{
122
    assert(bytes <= 8);
123
    put_byte(pb, 0x1ff >> bytes);
124
    while (--bytes)
125
        put_byte(pb, 0xff);
126
}
127

    
128
/**
129
 * Calculate how many bytes are needed to represent a given number in EBML.
130
 */
131
static int ebml_num_size(uint64_t num)
132
{
133
    int bytes = 1;
134
    while ((num+1) >> bytes*7) bytes++;
135
    return bytes;
136
}
137

    
138
/**
139
 * Write a number in EBML variable length format.
140
 *
141
 * @param bytes The number of bytes that need to be used to write the number.
142
 *              If zero, any number of bytes can be used.
143
 */
144
static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
145
{
146
    int i, needed_bytes = ebml_num_size(num);
147

    
148
    // sizes larger than this are currently undefined in EBML
149
    assert(num < (1ULL<<56)-1);
150

    
151
    if (bytes == 0)
152
        // don't care how many bytes are used, so use the min
153
        bytes = needed_bytes;
154
    // the bytes needed to write the given size would exceed the bytes
155
    // that we need to use, so write unknown size. This shouldn't happen.
156
    assert(bytes >= needed_bytes);
157

    
158
    num |= 1ULL << bytes*7;
159
    for (i = bytes - 1; i >= 0; i--)
160
        put_byte(pb, num >> i*8);
161
}
162

    
163
static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
164
{
165
    int i, bytes = 1;
166
    uint64_t tmp = val;
167
    while (tmp>>=8) bytes++;
168

    
169
    put_ebml_id(pb, elementid);
170
    put_ebml_num(pb, bytes, 0);
171
    for (i = bytes - 1; i >= 0; i--)
172
        put_byte(pb, val >> i*8);
173
}
174

    
175
static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
176
{
177
    put_ebml_id(pb, elementid);
178
    put_ebml_num(pb, 8, 0);
179
    put_be64(pb, av_dbl2int(val));
180
}
181

    
182
static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
183
                            const void *buf, int size)
184
{
185
    put_ebml_id(pb, elementid);
186
    put_ebml_num(pb, size, 0);
187
    put_buffer(pb, buf, size);
188
}
189

    
190
static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
191
{
192
    put_ebml_binary(pb, elementid, str, strlen(str));
193
}
194

    
195
/**
196
 * Write a void element of a given size. Useful for reserving space in
197
 * the file to be written to later.
198
 *
199
 * @param size The number of bytes to reserve, which must be at least 2.
200
 */
201
static void put_ebml_void(ByteIOContext *pb, uint64_t size)
202
{
203
    int64_t currentpos = url_ftell(pb);
204

    
205
    assert(size >= 2);
206

    
207
    put_ebml_id(pb, EBML_ID_VOID);
208
    // we need to subtract the length needed to store the size from the
209
    // size we need to reserve so 2 cases, we use 8 bytes to store the
210
    // size if possible, 1 byte otherwise
211
    if (size < 10)
212
        put_ebml_num(pb, size-1, 0);
213
    else
214
        put_ebml_num(pb, size-9, 8);
215
    while(url_ftell(pb) < currentpos + size)
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        put_byte(pb, 0);
217
}
218

    
219
static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
220
{
221
    int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
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    put_ebml_id(pb, elementid);
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    put_ebml_size_unknown(pb, bytes);
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    return (ebml_master){ url_ftell(pb), bytes };
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}
226

    
227
static void end_ebml_master(ByteIOContext *pb, ebml_master master)
228
{
229
    int64_t pos = url_ftell(pb);
230

    
231
    if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
232
        return;
233
    put_ebml_num(pb, pos - master.pos, master.sizebytes);
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    url_fseek(pb, pos, SEEK_SET);
235
}
236

    
237
static void put_xiph_size(ByteIOContext *pb, int size)
238
{
239
    int i;
240
    for (i = 0; i < size / 255; i++)
241
        put_byte(pb, 255);
242
    put_byte(pb, size % 255);
243
}
244

    
245
/**
246
 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
247
 * elements. If a maximum number of elements is specified, enough space
248
 * will be reserved at the current file location to write a seek head of
249
 * that size.
250
 *
251
 * @param segment_offset The absolute offset to the position in the file
252
 *                       where the segment begins.
253
 * @param numelements The maximum number of elements that will be indexed
254
 *                    by this seek head, 0 if unlimited.
255
 */
256
static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
257
{
258
    mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
259
    if (new_seekhead == NULL)
260
        return NULL;
261

    
262
    new_seekhead->segment_offset = segment_offset;
263

    
264
    if (numelements > 0) {
265
        new_seekhead->filepos = url_ftell(pb);
266
        // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
267
        // and size, and 3 bytes to guarantee that an EBML void element
268
        // will fit afterwards
269
        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
270
        new_seekhead->max_entries = numelements;
271
        put_ebml_void(pb, new_seekhead->reserved_size);
272
    }
273
    return new_seekhead;
274
}
275

    
276
static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
277
{
278
    mkv_seekhead_entry *entries = seekhead->entries;
279

    
280
    // don't store more elements than we reserved space for
281
    if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
282
        return -1;
283

    
284
    entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
285
    if (entries == NULL)
286
        return AVERROR(ENOMEM);
287

    
288
    entries[seekhead->num_entries  ].elementid = elementid;
289
    entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
290

    
291
    seekhead->entries = entries;
292
    return 0;
293
}
294

    
295
/**
296
 * Write the seek head to the file and free it. If a maximum number of
297
 * elements was specified to mkv_start_seekhead(), the seek head will
298
 * be written at the location reserved for it. Otherwise, it is written
299
 * at the current location in the file.
300
 *
301
 * @return The file offset where the seekhead was written,
302
 * -1 if an error occurred.
303
 */
304
static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
305
{
306
    ebml_master metaseek, seekentry;
307
    int64_t currentpos;
308
    int i;
309

    
310
    currentpos = url_ftell(pb);
311

    
312
    if (seekhead->reserved_size > 0)
313
        if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
314
            return -1;
315

    
316
    metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
317
    for (i = 0; i < seekhead->num_entries; i++) {
318
        mkv_seekhead_entry *entry = &seekhead->entries[i];
319

    
320
        seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
321

    
322
        put_ebml_id(pb, MATROSKA_ID_SEEKID);
323
        put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
324
        put_ebml_id(pb, entry->elementid);
325

    
326
        put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
327
        end_ebml_master(pb, seekentry);
328
    }
329
    end_ebml_master(pb, metaseek);
330

    
331
    if (seekhead->reserved_size > 0) {
332
        uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
333
        put_ebml_void(pb, remaining);
334
        url_fseek(pb, currentpos, SEEK_SET);
335

    
336
        currentpos = seekhead->filepos;
337
    }
338
    av_free(seekhead->entries);
339
    av_free(seekhead);
340

    
341
    return currentpos;
342
}
343

    
344
static mkv_cues * mkv_start_cues(int64_t segment_offset)
345
{
346
    mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
347
    if (cues == NULL)
348
        return NULL;
349

    
350
    cues->segment_offset = segment_offset;
351
    return cues;
352
}
353

    
354
static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
355
{
356
    mkv_cuepoint *entries = cues->entries;
357

    
358
    entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
359
    if (entries == NULL)
360
        return AVERROR(ENOMEM);
361

    
362
    if (ts < 0)
363
        return 0;
364

    
365
    entries[cues->num_entries  ].pts = ts;
366
    entries[cues->num_entries  ].tracknum = stream + 1;
367
    entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
368

    
369
    cues->entries = entries;
370
    return 0;
371
}
372

    
373
static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
374
{
375
    ebml_master cues_element;
376
    int64_t currentpos;
377
    int i, j;
378

    
379
    currentpos = url_ftell(pb);
380
    cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
381

    
382
    for (i = 0; i < cues->num_entries; i++) {
383
        ebml_master cuepoint, track_positions;
384
        mkv_cuepoint *entry = &cues->entries[i];
385
        uint64_t pts = entry->pts;
386

    
387
        cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
388
        put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
389

    
390
        // put all the entries from different tracks that have the exact same
391
        // timestamp into the same CuePoint
392
        for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
393
            track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
394
            put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
395
            put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
396
            end_ebml_master(pb, track_positions);
397
        }
398
        i += j - 1;
399
        end_ebml_master(pb, cuepoint);
400
    }
401
    end_ebml_master(pb, cues_element);
402

    
403
    av_free(cues->entries);
404
    av_free(cues);
405
    return currentpos;
406
}
407

    
408
static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
409
{
410
    uint8_t *header_start[3];
411
    int header_len[3];
412
    int first_header_size;
413
    int j;
414

    
415
    if (codec->codec_id == CODEC_ID_VORBIS)
416
        first_header_size = 30;
417
    else
418
        first_header_size = 42;
419

    
420
    if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
421
                              first_header_size, header_start, header_len) < 0) {
422
        av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
423
        return -1;
424
    }
425

    
426
    put_byte(pb, 2);                    // number packets - 1
427
    for (j = 0; j < 2; j++) {
428
        put_xiph_size(pb, header_len[j]);
429
    }
430
    for (j = 0; j < 3; j++)
431
        put_buffer(pb, header_start[j], header_len[j]);
432

    
433
    return 0;
434
}
435

    
436
static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
437
{
438
    int sri;
439

    
440
    if (codec->extradata_size < 2) {
441
        av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
442
        return;
443
    }
444

    
445
    sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
446
    if (sri > 12) {
447
        av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
448
        return;
449
    }
450
    *sample_rate = ff_mpeg4audio_sample_rates[sri];
451

    
452
    // if sbr, get output sample rate as well
453
    if (codec->extradata_size == 5) {
454
        sri = (codec->extradata[4] >> 3) & 0xF;
455
        if (sri > 12) {
456
            av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
457
            return;
458
        }
459
        *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
460
    }
461
}
462

    
463
static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
464
{
465
    ByteIOContext *dyn_cp;
466
    uint8_t *codecpriv;
467
    int ret, codecpriv_size;
468

    
469
    ret = url_open_dyn_buf(&dyn_cp);
470
    if(ret < 0)
471
        return ret;
472

    
473
    if (native_id) {
474
        if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
475
            ret = put_xiph_codecpriv(s, dyn_cp, codec);
476
        else if (codec->codec_id == CODEC_ID_FLAC)
477
            ret = ff_flac_write_header(dyn_cp, codec, 1);
478
        else if (codec->codec_id == CODEC_ID_H264)
479
            ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
480
        else if (codec->extradata_size)
481
            put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
482
    } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
483
        if (qt_id) {
484
            if (!codec->codec_tag)
485
                codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
486
            if (codec->extradata_size)
487
                put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
488
        } else {
489
            if (!codec->codec_tag)
490
                codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
491
            if (!codec->codec_tag) {
492
                av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
493
                ret = -1;
494
            }
495

    
496
            ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
497
        }
498

    
499
    } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
500
        unsigned int tag;
501
        tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
502
        if (!tag) {
503
            av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
504
            ret = -1;
505
        }
506
        if (!codec->codec_tag)
507
            codec->codec_tag = tag;
508

    
509
        ff_put_wav_header(dyn_cp, codec);
510
    }
511

    
512
    codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
513
    if (codecpriv_size)
514
        put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
515
    av_free(codecpriv);
516
    return ret;
517
}
518

    
519
static int mkv_write_tracks(AVFormatContext *s)
520
{
521
    MatroskaMuxContext *mkv = s->priv_data;
522
    ByteIOContext *pb = s->pb;
523
    ebml_master tracks;
524
    int i, j, ret;
525

    
526
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
527
    if (ret < 0) return ret;
528

    
529
    tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
530
    for (i = 0; i < s->nb_streams; i++) {
531
        AVStream *st = s->streams[i];
532
        AVCodecContext *codec = st->codec;
533
        ebml_master subinfo, track;
534
        int native_id = 0;
535
        int qt_id = 0;
536
        int bit_depth = av_get_bits_per_sample(codec->codec_id);
537
        int sample_rate = codec->sample_rate;
538
        int output_sample_rate = 0;
539
        AVMetadataTag *tag;
540

    
541
        if (!bit_depth)
542
            bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
543

    
544
        if (codec->codec_id == CODEC_ID_AAC)
545
            get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
546

    
547
        track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
548
        put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
549
        put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
550
        put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
551

    
552
        if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
553
            put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
554
        tag = av_metadata_get(st->metadata, "language", NULL, 0);
555
        put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
556

    
557
        if (st->disposition)
558
            put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
559

    
560
        // look for a codec ID string specific to mkv to use,
561
        // if none are found, use AVI codes
562
        for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
563
            if (ff_mkv_codec_tags[j].id == codec->codec_id) {
564
                put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
565
                native_id = 1;
566
                break;
567
            }
568
        }
569

    
570
        if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
571
                                        codec->codec_id == CODEC_ID_VORBIS)) {
572
            av_log(s, AV_LOG_ERROR,
573
                   "Only VP8 video and Vorbis audio are supported for WebM.\n");
574
            return AVERROR(EINVAL);
575
        }
576

    
577
        switch (codec->codec_type) {
578
            case AVMEDIA_TYPE_VIDEO:
579
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
580
                put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
581

    
582
                if (!native_id &&
583
                      ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
584
                    (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
585
                     || codec->codec_id == CODEC_ID_SVQ1
586
                     || codec->codec_id == CODEC_ID_SVQ3
587
                     || codec->codec_id == CODEC_ID_CINEPAK))
588
                    qt_id = 1;
589

    
590
                if (qt_id)
591
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
592
                else if (!native_id) {
593
                    // if there is no mkv-specific codec ID, use VFW mode
594
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
595
                    mkv->tracks[i].write_dts = 1;
596
                }
597

    
598
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
599
                // XXX: interlace flag?
600
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
601
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
602
                if (st->sample_aspect_ratio.num) {
603
                    int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
604
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
605
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
606
                }
607
                end_ebml_master(pb, subinfo);
608
                break;
609

    
610
            case AVMEDIA_TYPE_AUDIO:
611
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
612

    
613
                if (!native_id)
614
                    // no mkv-specific ID, use ACM mode
615
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
616

    
617
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
618
                put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
619
                put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
620
                if (output_sample_rate)
621
                    put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
622
                if (bit_depth)
623
                    put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
624
                end_ebml_master(pb, subinfo);
625
                break;
626

    
627
            case AVMEDIA_TYPE_SUBTITLE:
628
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
629
                break;
630
            default:
631
                av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
632
                break;
633
        }
634
        ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
635
        if (ret < 0) return ret;
636

    
637
        end_ebml_master(pb, track);
638

    
639
        // ms precision is the de-facto standard timescale for mkv files
640
        av_set_pts_info(st, 64, 1, 1000);
641
    }
642
    end_ebml_master(pb, tracks);
643
    return 0;
644
}
645

    
646
static int mkv_write_chapters(AVFormatContext *s)
647
{
648
    MatroskaMuxContext *mkv = s->priv_data;
649
    ByteIOContext *pb = s->pb;
650
    ebml_master chapters, editionentry;
651
    AVRational scale = {1, 1E9};
652
    int i, ret;
653

    
654
    if (!s->nb_chapters)
655
        return 0;
656

    
657
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
658
    if (ret < 0) return ret;
659

    
660
    chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
661
    editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
662
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
663
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
664
    for (i = 0; i < s->nb_chapters; i++) {
665
        ebml_master chapteratom, chapterdisplay;
666
        AVChapter *c     = s->chapters[i];
667
        AVMetadataTag *t = NULL;
668

    
669
        chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
670
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
671
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
672
                      av_rescale_q(c->start, c->time_base, scale));
673
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
674
                      av_rescale_q(c->end,   c->time_base, scale));
675
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
676
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
677
        if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
678
            chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
679
            put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
680
            put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
681
            end_ebml_master(pb, chapterdisplay);
682
        }
683
        end_ebml_master(pb, chapteratom);
684
    }
685
    end_ebml_master(pb, editionentry);
686
    end_ebml_master(pb, chapters);
687
    return 0;
688
}
689

    
690
static int mkv_write_header(AVFormatContext *s)
691
{
692
    MatroskaMuxContext *mkv = s->priv_data;
693
    ByteIOContext *pb = s->pb;
694
    ebml_master ebml_header, segment_info;
695
    AVMetadataTag *tag;
696
    int ret, i;
697

    
698
    if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
699
    else                                   mkv->mode = MODE_MATROSKAv2;
700

    
701
    mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
702
    if (!mkv->tracks)
703
        return AVERROR(ENOMEM);
704

    
705
    ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
706
    put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
707
    put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
708
    put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
709
    put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
710
    put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
711
    put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
712
    put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
713
    end_ebml_master(pb, ebml_header);
714

    
715
    mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
716
    mkv->segment_offset = url_ftell(pb);
717

    
718
    // we write 2 seek heads - one at the end of the file to point to each
719
    // cluster, and one at the beginning to point to all other level one
720
    // elements (including the seek head at the end of the file), which
721
    // isn't more than 10 elements if we only write one of each other
722
    // currently defined level 1 element
723
    mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
724
    if (!mkv->main_seekhead)
725
        return AVERROR(ENOMEM);
726

    
727
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
728
    if (ret < 0) return ret;
729

    
730
    segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
731
    put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
732
    if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
733
        put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
734
    if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
735
        uint32_t segment_uid[4];
736
        AVLFG lfg;
737

    
738
        av_lfg_init(&lfg, av_get_random_seed());
739

    
740
        for (i = 0; i < 4; i++)
741
            segment_uid[i] = av_lfg_get(&lfg);
742

    
743
        put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
744
        put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
745
        put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
746
    }
747

    
748
    // reserve space for the duration
749
    mkv->duration = 0;
750
    mkv->duration_offset = url_ftell(pb);
751
    put_ebml_void(pb, 11);                  // assumes double-precision float to be written
752
    end_ebml_master(pb, segment_info);
753

    
754
    ret = mkv_write_tracks(s);
755
    if (ret < 0) return ret;
756

    
757
    if (mkv->mode != MODE_WEBM) {
758
        ret = mkv_write_chapters(s);
759
        if (ret < 0) return ret;
760
    }
761

    
762
    if (url_is_streamed(s->pb))
763
        mkv_write_seekhead(pb, mkv->main_seekhead);
764

    
765
    mkv->cues = mkv_start_cues(mkv->segment_offset);
766
    if (mkv->cues == NULL)
767
        return AVERROR(ENOMEM);
768

    
769
    av_init_packet(&mkv->cur_audio_pkt);
770
    mkv->cur_audio_pkt.size = 0;
771
    mkv->audio_buffer_size  = 0;
772

    
773
    put_flush_packet(pb);
774
    return 0;
775
}
776

    
777
static int mkv_blockgroup_size(int pkt_size)
778
{
779
    int size = pkt_size + 4;
780
    size += ebml_num_size(size);
781
    size += 2;              // EBML ID for block and block duration
782
    size += 8;              // max size of block duration
783
    size += ebml_num_size(size);
784
    size += 1;              // blockgroup EBML ID
785
    return size;
786
}
787

    
788
static int ass_get_duration(const uint8_t *p)
789
{
790
    int sh, sm, ss, sc, eh, em, es, ec;
791
    uint64_t start, end;
792

    
793
    if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
794
               &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
795
        return 0;
796
    start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
797
    end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
798
    return end - start;
799
}
800

    
801
static int mkv_write_ass_blocks(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
802
{
803
    MatroskaMuxContext *mkv = s->priv_data;
804
    int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
805
    uint8_t *start, *end, *data = pkt->data;
806
    ebml_master blockgroup;
807
    char buffer[2048];
808

    
809
    while (data_size) {
810
        int duration = ass_get_duration(data);
811
        max_duration = FFMAX(duration, max_duration);
812
        end = memchr(data, '\n', data_size);
813
        size = line_size = end ? end-data+1 : data_size;
814
        size -= end ? (end[-1]=='\r')+1 : 0;
815
        start = data;
816
        for (i=0; i<3; i++, start++)
817
            if (!(start = memchr(start, ',', size-(start-data))))
818
                return max_duration;
819
        size -= start - data;
820
        sscanf(data, "Dialogue: %d,", &layer);
821
        i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
822
                     s->streams[pkt->stream_index]->nb_frames++, layer);
823
        size = FFMIN(i+size, sizeof(buffer));
824
        memcpy(buffer+i, start, size-i);
825

    
826
        av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
827
               "pts %" PRId64 ", duration %d\n",
828
               url_ftell(pb), size, pkt->pts, duration);
829
        blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
830
        put_ebml_id(pb, MATROSKA_ID_BLOCK);
831
        put_ebml_num(pb, size+4, 0);
832
        put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
833
        put_be16(pb, pkt->pts - mkv->cluster_pts);
834
        put_byte(pb, 0);
835
        put_buffer(pb, buffer, size);
836
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
837
        end_ebml_master(pb, blockgroup);
838

    
839
        data += line_size;
840
        data_size -= line_size;
841
    }
842

    
843
    return max_duration;
844
}
845

    
846
static void mkv_write_block(AVFormatContext *s, ByteIOContext *pb,
847
                            unsigned int blockid, AVPacket *pkt, int flags)
848
{
849
    MatroskaMuxContext *mkv = s->priv_data;
850
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
851
    uint8_t *data = NULL;
852
    int size = pkt->size;
853
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
854

    
855
    av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
856
           "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
857
           url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
858
    if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
859
        (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
860
        ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
861
    else
862
        data = pkt->data;
863
    put_ebml_id(pb, blockid);
864
    put_ebml_num(pb, size+4, 0);
865
    put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
866
    put_be16(pb, ts - mkv->cluster_pts);
867
    put_byte(pb, flags);
868
    put_buffer(pb, data, size);
869
    if (data != pkt->data)
870
        av_free(data);
871
}
872

    
873
static void mkv_flush_dynbuf(AVFormatContext *s)
874
{
875
    MatroskaMuxContext *mkv = s->priv_data;
876
    int bufsize;
877
    uint8_t *dyn_buf;
878

    
879
    if (!mkv->dyn_bc)
880
        return;
881

    
882
    bufsize = url_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
883
    put_buffer(s->pb, dyn_buf, bufsize);
884
    av_free(dyn_buf);
885
    mkv->dyn_bc = NULL;
886
}
887

    
888
static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
889
{
890
    MatroskaMuxContext *mkv = s->priv_data;
891
    ByteIOContext *pb = s->pb;
892
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
893
    int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
894
    int duration = pkt->duration;
895
    int ret;
896
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
897

    
898
    if (ts == AV_NOPTS_VALUE) {
899
        av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
900
        return AVERROR(EINVAL);
901
    }
902

    
903
    if (url_is_streamed(s->pb)) {
904
        if (!mkv->dyn_bc)
905
            url_open_dyn_buf(&mkv->dyn_bc);
906
        pb = mkv->dyn_bc;
907
    }
908

    
909
    if (!mkv->cluster_pos) {
910
        mkv->cluster_pos = url_ftell(s->pb);
911
        mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
912
        put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
913
        mkv->cluster_pts = FFMAX(0, ts);
914
    }
915

    
916
    if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
917
        mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
918
    } else if (codec->codec_id == CODEC_ID_SSA) {
919
        duration = mkv_write_ass_blocks(s, pb, pkt);
920
    } else {
921
        ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
922
        duration = pkt->convergence_duration;
923
        mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
924
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
925
        end_ebml_master(pb, blockgroup);
926
    }
927

    
928
    if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
929
        ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
930
        if (ret < 0) return ret;
931
    }
932

    
933
    mkv->duration = FFMAX(mkv->duration, ts + duration);
934
    return 0;
935
}
936

    
937
static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
938
{
939
    uint8_t *data           = mkv->cur_audio_pkt.data;
940
    mkv->cur_audio_pkt      = *pkt;
941
    mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
942
    if (!mkv->cur_audio_pkt.data)
943
        return AVERROR(ENOMEM);
944

    
945
    memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
946
    mkv->cur_audio_pkt.size = pkt->size;
947
    return 0;
948
}
949

    
950
static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
951
{
952
    MatroskaMuxContext *mkv = s->priv_data;
953
    ByteIOContext *pb = url_is_streamed(s->pb) ? mkv->dyn_bc : s->pb;
954
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
955
    int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
956
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
957
    int cluster_size = url_ftell(pb) - (url_is_streamed(s->pb) ? 0 : mkv->cluster_pos);
958

    
959
    // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
960
    // after 4k and on a keyframe
961
    if (mkv->cluster_pos &&
962
        ((url_is_streamed(s->pb) && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
963
         ||                      cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
964
         || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
965
        av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
966
               " bytes, pts %" PRIu64 "\n", url_ftell(pb), ts);
967
        end_ebml_master(pb, mkv->cluster);
968
        mkv->cluster_pos = 0;
969
        if (mkv->dyn_bc)
970
            mkv_flush_dynbuf(s);
971
    }
972

    
973
    // check if we have an audio packet cached
974
    if (mkv->cur_audio_pkt.size > 0) {
975
        ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
976
        mkv->cur_audio_pkt.size = 0;
977
        if (ret < 0) {
978
            av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
979
            return ret;
980
        }
981
    }
982

    
983
    // buffer an audio packet to ensure the packet containing the video
984
    // keyframe's timecode is contained in the same cluster for WebM
985
    if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
986
        ret = mkv_copy_packet(mkv, pkt);
987
    else
988
        ret = mkv_write_packet_internal(s, pkt);
989
    return ret;
990
}
991

    
992
static int mkv_write_trailer(AVFormatContext *s)
993
{
994
    MatroskaMuxContext *mkv = s->priv_data;
995
    ByteIOContext *pb = s->pb;
996
    int64_t currentpos, cuespos;
997
    int ret;
998

    
999
    // check if we have an audio packet cached
1000
    if (mkv->cur_audio_pkt.size > 0) {
1001
        ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1002
        mkv->cur_audio_pkt.size = 0;
1003
        if (ret < 0) {
1004
            av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1005
            return ret;
1006
        }
1007
    }
1008

    
1009
    if (mkv->dyn_bc) {
1010
        end_ebml_master(mkv->dyn_bc, mkv->cluster);
1011
        mkv_flush_dynbuf(s);
1012
    } else if (mkv->cluster_pos) {
1013
        end_ebml_master(pb, mkv->cluster);
1014
    }
1015

    
1016
    if (!url_is_streamed(pb)) {
1017
        cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
1018

    
1019
        ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
1020
        if (ret < 0) return ret;
1021
        mkv_write_seekhead(pb, mkv->main_seekhead);
1022

    
1023
        // update the duration
1024
        av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
1025
        currentpos = url_ftell(pb);
1026
        url_fseek(pb, mkv->duration_offset, SEEK_SET);
1027
        put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
1028

    
1029
        url_fseek(pb, currentpos, SEEK_SET);
1030
    }
1031

    
1032
    end_ebml_master(pb, mkv->segment);
1033
    av_free(mkv->tracks);
1034
    av_destruct_packet(&mkv->cur_audio_pkt);
1035
    put_flush_packet(pb);
1036
    return 0;
1037
}
1038

    
1039
#if CONFIG_MATROSKA_MUXER
1040
AVOutputFormat matroska_muxer = {
1041
    "matroska",
1042
    NULL_IF_CONFIG_SMALL("Matroska file format"),
1043
    "video/x-matroska",
1044
    "mkv",
1045
    sizeof(MatroskaMuxContext),
1046
    CODEC_ID_MP2,
1047
    CODEC_ID_MPEG4,
1048
    mkv_write_header,
1049
    mkv_write_packet,
1050
    mkv_write_trailer,
1051
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1052
    .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
1053
    .subtitle_codec = CODEC_ID_TEXT,
1054
};
1055
#endif
1056

    
1057
#if CONFIG_WEBM_MUXER
1058
AVOutputFormat webm_muxer = {
1059
    "webm",
1060
    NULL_IF_CONFIG_SMALL("WebM file format"),
1061
    "video/webm",
1062
    "webm",
1063
    sizeof(MatroskaMuxContext),
1064
    CODEC_ID_VORBIS,
1065
    CODEC_ID_VP8,
1066
    mkv_write_header,
1067
    mkv_write_packet,
1068
    mkv_write_trailer,
1069
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1070
};
1071
#endif
1072

    
1073
#if CONFIG_MATROSKA_AUDIO_MUXER
1074
AVOutputFormat matroska_audio_muxer = {
1075
    "matroska",
1076
    NULL_IF_CONFIG_SMALL("Matroska file format"),
1077
    "audio/x-matroska",
1078
    "mka",
1079
    sizeof(MatroskaMuxContext),
1080
    CODEC_ID_MP2,
1081
    CODEC_ID_NONE,
1082
    mkv_write_header,
1083
    mkv_write_packet,
1084
    mkv_write_trailer,
1085
    .flags = AVFMT_GLOBALHEADER,
1086
    .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
1087
};
1088
#endif