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ffmpeg / libavformat / matroskaenc.c @ e7ddafd5

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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

    
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#define MODE_MATROSKAv2 0x01
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#define MODE_WEBM       0x02
71

    
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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
    AVLFG           lfg;
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    unsigned int    audio_buffer_size;
88
    AVPacket        cur_audio_pkt;
89
} MatroskaMuxContext;
90

    
91

    
92
/** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
93
 * offset, 4 bytes for target EBML ID */
94
#define MAX_SEEKENTRY_SIZE 21
95

    
96
/** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
97
 * 8-byte uint max */
98
#define MAX_CUETRACKPOS_SIZE 22
99

    
100
/** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
101
#define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
102

    
103

    
104
static int ebml_id_size(unsigned int id)
105
{
106
    return (av_log2(id+1)-1)/7+1;
107
}
108

    
109
static void put_ebml_id(ByteIOContext *pb, unsigned int id)
110
{
111
    int i = ebml_id_size(id);
112
    while (i--)
113
        put_byte(pb, id >> (i*8));
114
}
115

    
116
/**
117
 * Write an EBML size meaning "unknown size".
118
 *
119
 * @param bytes The number of bytes the size should occupy (maximum: 8).
120
 */
121
static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
122
{
123
    assert(bytes <= 8);
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    put_byte(pb, 0x1ff >> bytes);
125
    while (--bytes)
126
        put_byte(pb, 0xff);
127
}
128

    
129
/**
130
 * Calculate how many bytes are needed to represent a given number in EBML.
131
 */
132
static int ebml_num_size(uint64_t num)
133
{
134
    int bytes = 1;
135
    while ((num+1) >> bytes*7) bytes++;
136
    return bytes;
137
}
138

    
139
/**
140
 * Write a number in EBML variable length format.
141
 *
142
 * @param bytes The number of bytes that need to be used to write the number.
143
 *              If zero, any number of bytes can be used.
144
 */
145
static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
146
{
147
    int i, needed_bytes = ebml_num_size(num);
148

    
149
    // sizes larger than this are currently undefined in EBML
150
    assert(num < (1ULL<<56)-1);
151

    
152
    if (bytes == 0)
153
        // don't care how many bytes are used, so use the min
154
        bytes = needed_bytes;
155
    // the bytes needed to write the given size would exceed the bytes
156
    // that we need to use, so write unknown size. This shouldn't happen.
157
    assert(bytes >= needed_bytes);
158

    
159
    num |= 1ULL << bytes*7;
160
    for (i = bytes - 1; i >= 0; i--)
161
        put_byte(pb, num >> i*8);
162
}
163

    
164
static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
165
{
166
    int i, bytes = 1;
167
    uint64_t tmp = val;
168
    while (tmp>>=8) bytes++;
169

    
170
    put_ebml_id(pb, elementid);
171
    put_ebml_num(pb, bytes, 0);
172
    for (i = bytes - 1; i >= 0; i--)
173
        put_byte(pb, val >> i*8);
174
}
175

    
176
static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
177
{
178
    put_ebml_id(pb, elementid);
179
    put_ebml_num(pb, 8, 0);
180
    put_be64(pb, av_dbl2int(val));
181
}
182

    
183
static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
184
                            const void *buf, int size)
185
{
186
    put_ebml_id(pb, elementid);
187
    put_ebml_num(pb, size, 0);
188
    put_buffer(pb, buf, size);
189
}
190

    
191
static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
192
{
193
    put_ebml_binary(pb, elementid, str, strlen(str));
194
}
195

    
196
/**
197
 * Writes a void element of a given size. Useful for reserving space in
198
 * the file to be written to later.
199
 *
200
 * @param size The number of bytes to reserve, which must be at least 2.
201
 */
202
static void put_ebml_void(ByteIOContext *pb, uint64_t size)
203
{
204
    int64_t currentpos = url_ftell(pb);
205

    
206
    assert(size >= 2);
207

    
208
    put_ebml_id(pb, EBML_ID_VOID);
209
    // we need to subtract the length needed to store the size from the
210
    // size we need to reserve so 2 cases, we use 8 bytes to store the
211
    // size if possible, 1 byte otherwise
212
    if (size < 10)
213
        put_ebml_num(pb, size-1, 0);
214
    else
215
        put_ebml_num(pb, size-9, 8);
216
    while(url_ftell(pb) < currentpos + size)
217
        put_byte(pb, 0);
218
}
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220
static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
221
{
222
    int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
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    put_ebml_id(pb, elementid);
224
    put_ebml_size_unknown(pb, bytes);
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    return (ebml_master){ url_ftell(pb), bytes };
226
}
227

    
228
static void end_ebml_master(ByteIOContext *pb, ebml_master master)
229
{
230
    int64_t pos = url_ftell(pb);
231

    
232
    if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
233
        return;
234
    put_ebml_num(pb, pos - master.pos, master.sizebytes);
235
    url_fseek(pb, pos, SEEK_SET);
236
}
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238
static void put_xiph_size(ByteIOContext *pb, int size)
239
{
240
    int i;
241
    for (i = 0; i < size / 255; i++)
242
        put_byte(pb, 255);
243
    put_byte(pb, size % 255);
244
}
245

    
246
/**
247
 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
248
 * elements. If a maximum number of elements is specified, enough space
249
 * will be reserved at the current file location to write a seek head of
250
 * that size.
251
 *
252
 * @param segment_offset The absolute offset to the position in the file
253
 *                       where the segment begins.
254
 * @param numelements The maximum number of elements that will be indexed
255
 *                    by this seek head, 0 if unlimited.
256
 */
257
static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
258
{
259
    mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
260
    if (new_seekhead == NULL)
261
        return NULL;
262

    
263
    new_seekhead->segment_offset = segment_offset;
264

    
265
    if (numelements > 0) {
266
        new_seekhead->filepos = url_ftell(pb);
267
        // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
268
        // and size, and 3 bytes to guarantee that an EBML void element
269
        // will fit afterwards
270
        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
271
        new_seekhead->max_entries = numelements;
272
        put_ebml_void(pb, new_seekhead->reserved_size);
273
    }
274
    return new_seekhead;
275
}
276

    
277
static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
278
{
279
    mkv_seekhead_entry *entries = seekhead->entries;
280

    
281
    // don't store more elements than we reserved space for
282
    if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
283
        return -1;
284

    
285
    entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
286
    if (entries == NULL)
287
        return AVERROR(ENOMEM);
288

    
289
    entries[seekhead->num_entries  ].elementid = elementid;
290
    entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
291

    
292
    seekhead->entries = entries;
293
    return 0;
294
}
295

    
296
/**
297
 * Write the seek head to the file and free it. If a maximum number of
298
 * elements was specified to mkv_start_seekhead(), the seek head will
299
 * be written at the location reserved for it. Otherwise, it is written
300
 * at the current location in the file.
301
 *
302
 * @return The file offset where the seekhead was written,
303
 * -1 if an error occurred.
304
 */
305
static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
306
{
307
    ebml_master metaseek, seekentry;
308
    int64_t currentpos;
309
    int i;
310

    
311
    currentpos = url_ftell(pb);
312

    
313
    if (seekhead->reserved_size > 0)
314
        if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
315
            return -1;
316

    
317
    metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
318
    for (i = 0; i < seekhead->num_entries; i++) {
319
        mkv_seekhead_entry *entry = &seekhead->entries[i];
320

    
321
        seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
322

    
323
        put_ebml_id(pb, MATROSKA_ID_SEEKID);
324
        put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
325
        put_ebml_id(pb, entry->elementid);
326

    
327
        put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
328
        end_ebml_master(pb, seekentry);
329
    }
330
    end_ebml_master(pb, metaseek);
331

    
332
    if (seekhead->reserved_size > 0) {
333
        uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
334
        put_ebml_void(pb, remaining);
335
        url_fseek(pb, currentpos, SEEK_SET);
336

    
337
        currentpos = seekhead->filepos;
338
    }
339
    av_free(seekhead->entries);
340
    av_free(seekhead);
341

    
342
    return currentpos;
343
}
344

    
345
static mkv_cues * mkv_start_cues(int64_t segment_offset)
346
{
347
    mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
348
    if (cues == NULL)
349
        return NULL;
350

    
351
    cues->segment_offset = segment_offset;
352
    return cues;
353
}
354

    
355
static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
356
{
357
    mkv_cuepoint *entries = cues->entries;
358

    
359
    entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
360
    if (entries == NULL)
361
        return AVERROR(ENOMEM);
362

    
363
    if (ts < 0)
364
        return 0;
365

    
366
    entries[cues->num_entries  ].pts = ts;
367
    entries[cues->num_entries  ].tracknum = stream + 1;
368
    entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
369

    
370
    cues->entries = entries;
371
    return 0;
372
}
373

    
374
static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
375
{
376
    ebml_master cues_element;
377
    int64_t currentpos;
378
    int i, j;
379

    
380
    currentpos = url_ftell(pb);
381
    cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
382

    
383
    for (i = 0; i < cues->num_entries; i++) {
384
        ebml_master cuepoint, track_positions;
385
        mkv_cuepoint *entry = &cues->entries[i];
386
        uint64_t pts = entry->pts;
387

    
388
        cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
389
        put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
390

    
391
        // put all the entries from different tracks that have the exact same
392
        // timestamp into the same CuePoint
393
        for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
394
            track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
395
            put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
396
            put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
397
            end_ebml_master(pb, track_positions);
398
        }
399
        i += j - 1;
400
        end_ebml_master(pb, cuepoint);
401
    }
402
    end_ebml_master(pb, cues_element);
403

    
404
    av_free(cues->entries);
405
    av_free(cues);
406
    return currentpos;
407
}
408

    
409
static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
410
{
411
    uint8_t *header_start[3];
412
    int header_len[3];
413
    int first_header_size;
414
    int j;
415

    
416
    if (codec->codec_id == CODEC_ID_VORBIS)
417
        first_header_size = 30;
418
    else
419
        first_header_size = 42;
420

    
421
    if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
422
                              first_header_size, header_start, header_len) < 0) {
423
        av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
424
        return -1;
425
    }
426

    
427
    put_byte(pb, 2);                    // number packets - 1
428
    for (j = 0; j < 2; j++) {
429
        put_xiph_size(pb, header_len[j]);
430
    }
431
    for (j = 0; j < 3; j++)
432
        put_buffer(pb, header_start[j], header_len[j]);
433

    
434
    return 0;
435
}
436

    
437
static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
438
{
439
    int sri;
440

    
441
    if (codec->extradata_size < 2) {
442
        av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
443
        return;
444
    }
445

    
446
    sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
447
    if (sri > 12) {
448
        av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
449
        return;
450
    }
451
    *sample_rate = ff_mpeg4audio_sample_rates[sri];
452

    
453
    // if sbr, get output sample rate as well
454
    if (codec->extradata_size == 5) {
455
        sri = (codec->extradata[4] >> 3) & 0xF;
456
        if (sri > 12) {
457
            av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
458
            return;
459
        }
460
        *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
461
    }
462
}
463

    
464
static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
465
{
466
    ByteIOContext *dyn_cp;
467
    uint8_t *codecpriv;
468
    int ret, codecpriv_size;
469

    
470
    ret = url_open_dyn_buf(&dyn_cp);
471
    if(ret < 0)
472
        return ret;
473

    
474
    if (native_id) {
475
        if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
476
            ret = put_xiph_codecpriv(s, dyn_cp, codec);
477
        else if (codec->codec_id == CODEC_ID_FLAC)
478
            ret = ff_flac_write_header(dyn_cp, codec, 1);
479
        else if (codec->codec_id == CODEC_ID_H264)
480
            ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
481
        else if (codec->extradata_size)
482
            put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
483
    } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
484
        if (qt_id) {
485
            if (!codec->codec_tag)
486
                codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
487
            if (codec->extradata_size)
488
                put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
489
        } else {
490
            if (!codec->codec_tag)
491
                codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
492
            if (!codec->codec_tag) {
493
                av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
494
                ret = -1;
495
            }
496

    
497
            ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
498
        }
499

    
500
    } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
501
        unsigned int tag;
502
        tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
503
        if (!tag) {
504
            av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
505
            ret = -1;
506
        }
507
        if (!codec->codec_tag)
508
            codec->codec_tag = tag;
509

    
510
        ff_put_wav_header(dyn_cp, codec);
511
    }
512

    
513
    codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
514
    if (codecpriv_size)
515
        put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
516
    av_free(codecpriv);
517
    return ret;
518
}
519

    
520
static int mkv_write_tracks(AVFormatContext *s)
521
{
522
    MatroskaMuxContext *mkv = s->priv_data;
523
    ByteIOContext *pb = s->pb;
524
    ebml_master tracks;
525
    int i, j, ret;
526

    
527
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
528
    if (ret < 0) return ret;
529

    
530
    tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
531
    for (i = 0; i < s->nb_streams; i++) {
532
        AVStream *st = s->streams[i];
533
        AVCodecContext *codec = st->codec;
534
        ebml_master subinfo, track;
535
        int native_id = 0;
536
        int qt_id = 0;
537
        int bit_depth = av_get_bits_per_sample(codec->codec_id);
538
        int sample_rate = codec->sample_rate;
539
        int output_sample_rate = 0;
540
        AVMetadataTag *tag;
541

    
542
        if (!bit_depth)
543
            bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
544

    
545
        if (codec->codec_id == CODEC_ID_AAC)
546
            get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
547

    
548
        track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
549
        put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
550
        put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
551
        put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
552

    
553
        if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
554
            put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
555
        tag = av_metadata_get(st->metadata, "language", NULL, 0);
556
        put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
557

    
558
        if (st->disposition)
559
            put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
560

    
561
        // look for a codec ID string specific to mkv to use,
562
        // if none are found, use AVI codes
563
        for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
564
            if (ff_mkv_codec_tags[j].id == codec->codec_id) {
565
                put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
566
                native_id = 1;
567
                break;
568
            }
569
        }
570

    
571
        if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
572
                                        codec->codec_id == CODEC_ID_VORBIS)) {
573
            av_log(s, AV_LOG_ERROR,
574
                   "Only VP8 video and Vorbis audio are supported for WebM.\n");
575
            return AVERROR(EINVAL);
576
        }
577

    
578
        switch (codec->codec_type) {
579
            case AVMEDIA_TYPE_VIDEO:
580
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
581
                put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
582

    
583
                if (!native_id &&
584
                      ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
585
                    (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
586
                     || codec->codec_id == CODEC_ID_SVQ1
587
                     || codec->codec_id == CODEC_ID_SVQ3
588
                     || codec->codec_id == CODEC_ID_CINEPAK))
589
                    qt_id = 1;
590

    
591
                if (qt_id)
592
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
593
                else if (!native_id) {
594
                    // if there is no mkv-specific codec ID, use VFW mode
595
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
596
                    mkv->tracks[i].write_dts = 1;
597
                }
598

    
599
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
600
                // XXX: interlace flag?
601
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
602
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
603
                if (st->sample_aspect_ratio.num) {
604
                    int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
605
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
606
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
607
                }
608
                end_ebml_master(pb, subinfo);
609
                break;
610

    
611
            case AVMEDIA_TYPE_AUDIO:
612
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
613

    
614
                if (!native_id)
615
                    // no mkv-specific ID, use ACM mode
616
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
617

    
618
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
619
                put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
620
                put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
621
                if (output_sample_rate)
622
                    put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
623
                if (bit_depth)
624
                    put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
625
                end_ebml_master(pb, subinfo);
626
                break;
627

    
628
            case AVMEDIA_TYPE_SUBTITLE:
629
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
630
                break;
631
            default:
632
                av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
633
                break;
634
        }
635
        ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
636
        if (ret < 0) return ret;
637

    
638
        end_ebml_master(pb, track);
639

    
640
        // ms precision is the de-facto standard timescale for mkv files
641
        av_set_pts_info(st, 64, 1, 1000);
642
    }
643
    end_ebml_master(pb, tracks);
644
    return 0;
645
}
646

    
647
static int mkv_write_chapters(AVFormatContext *s)
648
{
649
    MatroskaMuxContext *mkv = s->priv_data;
650
    ByteIOContext *pb = s->pb;
651
    ebml_master chapters, editionentry;
652
    AVRational scale = {1, 1E9};
653
    int i, ret;
654

    
655
    if (!s->nb_chapters)
656
        return 0;
657

    
658
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
659
    if (ret < 0) return ret;
660

    
661
    chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
662
    editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
663
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
664
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
665
    for (i = 0; i < s->nb_chapters; i++) {
666
        ebml_master chapteratom, chapterdisplay;
667
        AVChapter *c     = s->chapters[i];
668
        AVMetadataTag *t = NULL;
669

    
670
        chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
671
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
672
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
673
                      av_rescale_q(c->start, c->time_base, scale));
674
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
675
                      av_rescale_q(c->end,   c->time_base, scale));
676
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
677
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
678
        if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
679
            chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
680
            put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
681
            put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
682
            end_ebml_master(pb, chapterdisplay);
683
        }
684
        end_ebml_master(pb, chapteratom);
685
    }
686
    end_ebml_master(pb, editionentry);
687
    end_ebml_master(pb, chapters);
688
    return 0;
689
}
690

    
691
static int mkv_write_header(AVFormatContext *s)
692
{
693
    MatroskaMuxContext *mkv = s->priv_data;
694
    ByteIOContext *pb = s->pb;
695
    ebml_master ebml_header, segment_info;
696
    AVMetadataTag *tag;
697
    int ret, i;
698

    
699
    if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
700
    else                                   mkv->mode = MODE_MATROSKAv2;
701

    
702
    av_lfg_init(&mkv->lfg, av_get_random_seed());
703

    
704
    mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
705
    if (!mkv->tracks)
706
        return AVERROR(ENOMEM);
707

    
708
    ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
709
    put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
710
    put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
711
    put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
712
    put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
713
    put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
714
    put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
715
    put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
716
    end_ebml_master(pb, ebml_header);
717

    
718
    mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
719
    mkv->segment_offset = url_ftell(pb);
720

    
721
    // we write 2 seek heads - one at the end of the file to point to each
722
    // cluster, and one at the beginning to point to all other level one
723
    // elements (including the seek head at the end of the file), which
724
    // isn't more than 10 elements if we only write one of each other
725
    // currently defined level 1 element
726
    mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
727
    if (!mkv->main_seekhead)
728
        return AVERROR(ENOMEM);
729

    
730
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
731
    if (ret < 0) return ret;
732

    
733
    segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
734
    put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
735
    if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
736
        put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
737
    if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
738
        uint32_t segment_uid[4];
739
        for (i = 0; i < 4; i++)
740
            segment_uid[i] = av_lfg_get(&mkv->lfg);
741

    
742
        put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
743
        put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
744
        put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
745
    }
746

    
747
    // reserve space for the duration
748
    mkv->duration = 0;
749
    mkv->duration_offset = url_ftell(pb);
750
    put_ebml_void(pb, 11);                  // assumes double-precision float to be written
751
    end_ebml_master(pb, segment_info);
752

    
753
    ret = mkv_write_tracks(s);
754
    if (ret < 0) return ret;
755

    
756
    if (mkv->mode != MODE_WEBM) {
757
        ret = mkv_write_chapters(s);
758
        if (ret < 0) return ret;
759
    }
760

    
761
    if (url_is_streamed(s->pb))
762
        mkv_write_seekhead(pb, mkv->main_seekhead);
763

    
764
    mkv->cues = mkv_start_cues(mkv->segment_offset);
765
    if (mkv->cues == NULL)
766
        return AVERROR(ENOMEM);
767

    
768
    av_init_packet(&mkv->cur_audio_pkt);
769
    mkv->cur_audio_pkt.size = 0;
770
    mkv->audio_buffer_size  = 0;
771

    
772
    put_flush_packet(pb);
773
    return 0;
774
}
775

    
776
static int mkv_blockgroup_size(int pkt_size)
777
{
778
    int size = pkt_size + 4;
779
    size += ebml_num_size(size);
780
    size += 2;              // EBML ID for block and block duration
781
    size += 8;              // max size of block duration
782
    size += ebml_num_size(size);
783
    size += 1;              // blockgroup EBML ID
784
    return size;
785
}
786

    
787
static int ass_get_duration(const uint8_t *p)
788
{
789
    int sh, sm, ss, sc, eh, em, es, ec;
790
    uint64_t start, end;
791

    
792
    if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
793
               &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
794
        return 0;
795
    start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
796
    end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
797
    return end - start;
798
}
799

    
800
static int mkv_write_ass_blocks(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
801
{
802
    MatroskaMuxContext *mkv = s->priv_data;
803
    int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
804
    uint8_t *start, *end, *data = pkt->data;
805
    ebml_master blockgroup;
806
    char buffer[2048];
807

    
808
    while (data_size) {
809
        int duration = ass_get_duration(data);
810
        max_duration = FFMAX(duration, max_duration);
811
        end = memchr(data, '\n', data_size);
812
        size = line_size = end ? end-data+1 : data_size;
813
        size -= end ? (end[-1]=='\r')+1 : 0;
814
        start = data;
815
        for (i=0; i<3; i++, start++)
816
            if (!(start = memchr(start, ',', size-(start-data))))
817
                return max_duration;
818
        size -= start - data;
819
        sscanf(data, "Dialogue: %d,", &layer);
820
        i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
821
                     s->streams[pkt->stream_index]->nb_frames++, layer);
822
        size = FFMIN(i+size, sizeof(buffer));
823
        memcpy(buffer+i, start, size-i);
824

    
825
        av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
826
               "pts %" PRId64 ", duration %d\n",
827
               url_ftell(pb), size, pkt->pts, duration);
828
        blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
829
        put_ebml_id(pb, MATROSKA_ID_BLOCK);
830
        put_ebml_num(pb, size+4, 0);
831
        put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
832
        put_be16(pb, pkt->pts - mkv->cluster_pts);
833
        put_byte(pb, 0);
834
        put_buffer(pb, buffer, size);
835
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
836
        end_ebml_master(pb, blockgroup);
837

    
838
        data += line_size;
839
        data_size -= line_size;
840
    }
841

    
842
    return max_duration;
843
}
844

    
845
static void mkv_write_block(AVFormatContext *s, ByteIOContext *pb,
846
                            unsigned int blockid, AVPacket *pkt, int flags)
847
{
848
    MatroskaMuxContext *mkv = s->priv_data;
849
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
850
    uint8_t *data = NULL;
851
    int size = pkt->size;
852
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
853

    
854
    av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
855
           "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
856
           url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
857
    if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
858
        (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
859
        ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
860
    else
861
        data = pkt->data;
862
    put_ebml_id(pb, blockid);
863
    put_ebml_num(pb, size+4, 0);
864
    put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
865
    put_be16(pb, ts - mkv->cluster_pts);
866
    put_byte(pb, flags);
867
    put_buffer(pb, data, size);
868
    if (data != pkt->data)
869
        av_free(data);
870
}
871

    
872
static void mkv_flush_dynbuf(AVFormatContext *s)
873
{
874
    MatroskaMuxContext *mkv = s->priv_data;
875
    int bufsize;
876
    uint8_t *dyn_buf;
877

    
878
    if (!mkv->dyn_bc)
879
        return;
880

    
881
    bufsize = url_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
882
    put_buffer(s->pb, dyn_buf, bufsize);
883
    av_free(dyn_buf);
884
    mkv->dyn_bc = NULL;
885
}
886

    
887
static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
888
{
889
    MatroskaMuxContext *mkv = s->priv_data;
890
    ByteIOContext *pb = s->pb;
891
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
892
    int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
893
    int duration = pkt->duration;
894
    int ret;
895
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
896

    
897
    if (ts == AV_NOPTS_VALUE) {
898
        av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
899
        return AVERROR(EINVAL);
900
    }
901

    
902
    if (url_is_streamed(s->pb)) {
903
        if (!mkv->dyn_bc)
904
            url_open_dyn_buf(&mkv->dyn_bc);
905
        pb = mkv->dyn_bc;
906
    }
907

    
908
    if (!mkv->cluster_pos) {
909
        mkv->cluster_pos = url_ftell(s->pb);
910
        mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
911
        put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
912
        mkv->cluster_pts = FFMAX(0, ts);
913
    }
914

    
915
    if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
916
        mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
917
    } else if (codec->codec_id == CODEC_ID_SSA) {
918
        duration = mkv_write_ass_blocks(s, pb, pkt);
919
    } else {
920
        ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
921
        duration = pkt->convergence_duration;
922
        mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
923
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
924
        end_ebml_master(pb, blockgroup);
925
    }
926

    
927
    if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
928
        ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
929
        if (ret < 0) return ret;
930
    }
931

    
932
    mkv->duration = FFMAX(mkv->duration, ts + duration);
933
    return 0;
934
}
935

    
936
static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
937
{
938
    uint8_t *data           = mkv->cur_audio_pkt.data;
939
    mkv->cur_audio_pkt      = *pkt;
940
    mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
941
    if (!mkv->cur_audio_pkt.data)
942
        return AVERROR(ENOMEM);
943

    
944
    memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
945
    mkv->cur_audio_pkt.size = pkt->size;
946
    return 0;
947
}
948

    
949
static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
950
{
951
    MatroskaMuxContext *mkv = s->priv_data;
952
    ByteIOContext *pb = url_is_streamed(s->pb) ? mkv->dyn_bc : s->pb;
953
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
954
    int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
955
    int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
956
    int cluster_size = url_ftell(pb) - (url_is_streamed(s->pb) ? 0 : mkv->cluster_pos);
957

    
958
    // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
959
    // after 4k and on a keyframe
960
    if (mkv->cluster_pos &&
961
        ((url_is_streamed(s->pb) && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
962
         ||                      cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
963
         || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
964
        av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
965
               " bytes, pts %" PRIu64 "\n", url_ftell(pb), ts);
966
        end_ebml_master(pb, mkv->cluster);
967
        mkv->cluster_pos = 0;
968
        if (mkv->dyn_bc)
969
            mkv_flush_dynbuf(s);
970
    }
971

    
972
    // check if we have an audio packet cached
973
    if (mkv->cur_audio_pkt.size > 0) {
974
        ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
975
        mkv->cur_audio_pkt.size = 0;
976
        if (ret < 0) {
977
            av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
978
            return ret;
979
        }
980
    }
981

    
982
    // buffer an audio packet to ensure the packet containing the video
983
    // keyframe's timecode is contained in the same cluster for WebM
984
    if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
985
        ret = mkv_copy_packet(mkv, pkt);
986
    else
987
        ret = mkv_write_packet_internal(s, pkt);
988
    return ret;
989
}
990

    
991
static int mkv_write_trailer(AVFormatContext *s)
992
{
993
    MatroskaMuxContext *mkv = s->priv_data;
994
    ByteIOContext *pb = s->pb;
995
    int64_t currentpos, cuespos;
996
    int ret;
997

    
998
    // check if we have an audio packet cached
999
    if (mkv->cur_audio_pkt.size > 0) {
1000
        ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1001
        mkv->cur_audio_pkt.size = 0;
1002
        if (ret < 0) {
1003
            av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1004
            return ret;
1005
        }
1006
    }
1007

    
1008
    if (mkv->dyn_bc) {
1009
        end_ebml_master(mkv->dyn_bc, mkv->cluster);
1010
        mkv_flush_dynbuf(s);
1011
    } else if (mkv->cluster_pos) {
1012
        end_ebml_master(pb, mkv->cluster);
1013
    }
1014

    
1015
    if (!url_is_streamed(pb)) {
1016
        cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
1017

    
1018
        ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
1019
        if (ret < 0) return ret;
1020
        mkv_write_seekhead(pb, mkv->main_seekhead);
1021

    
1022
        // update the duration
1023
        av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
1024
        currentpos = url_ftell(pb);
1025
        url_fseek(pb, mkv->duration_offset, SEEK_SET);
1026
        put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
1027

    
1028
        url_fseek(pb, currentpos, SEEK_SET);
1029
    }
1030

    
1031
    end_ebml_master(pb, mkv->segment);
1032
    av_free(mkv->tracks);
1033
    av_destruct_packet(&mkv->cur_audio_pkt);
1034
    put_flush_packet(pb);
1035
    return 0;
1036
}
1037

    
1038
#if CONFIG_MATROSKA_MUXER
1039
AVOutputFormat matroska_muxer = {
1040
    "matroska",
1041
    NULL_IF_CONFIG_SMALL("Matroska file format"),
1042
    "video/x-matroska",
1043
    "mkv",
1044
    sizeof(MatroskaMuxContext),
1045
    CODEC_ID_MP2,
1046
    CODEC_ID_MPEG4,
1047
    mkv_write_header,
1048
    mkv_write_packet,
1049
    mkv_write_trailer,
1050
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1051
    .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
1052
    .subtitle_codec = CODEC_ID_TEXT,
1053
};
1054
#endif
1055

    
1056
#if CONFIG_WEBM_MUXER
1057
AVOutputFormat webm_muxer = {
1058
    "webm",
1059
    NULL_IF_CONFIG_SMALL("WebM file format"),
1060
    "video/webm",
1061
    "webm",
1062
    sizeof(MatroskaMuxContext),
1063
    CODEC_ID_VORBIS,
1064
    CODEC_ID_VP8,
1065
    mkv_write_header,
1066
    mkv_write_packet,
1067
    mkv_write_trailer,
1068
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1069
};
1070
#endif
1071

    
1072
#if CONFIG_MATROSKA_AUDIO_MUXER
1073
AVOutputFormat matroska_audio_muxer = {
1074
    "matroska",
1075
    NULL_IF_CONFIG_SMALL("Matroska file format"),
1076
    "audio/x-matroska",
1077
    "mka",
1078
    sizeof(MatroskaMuxContext),
1079
    CODEC_ID_MP2,
1080
    CODEC_ID_NONE,
1081
    mkv_write_header,
1082
    mkv_write_packet,
1083
    mkv_write_trailer,
1084
    .flags = AVFMT_GLOBALHEADER,
1085
    .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
1086
};
1087
#endif