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ffmpeg / libavformat / matroskaenc.c @ 30f06a58

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1
/*
2
 * Matroska muxer
3
 * Copyright (c) 2007 David Conrad
4
 *
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 * 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
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 * 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,
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 * 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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 */
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#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/md5.h"
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#include "libavcodec/xiph.h"
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#include "libavcodec/mpeg4audio.h"
32

    
33
typedef struct ebml_master {
34
    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;
37

    
38
typedef struct mkv_seekhead_entry {
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    unsigned int    elementid;
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    uint64_t        segmentpos;
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} mkv_seekhead_entry;
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43
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;
51

    
52
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
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} mkv_cuepoint;
57

    
58
typedef struct {
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    int64_t         segment_offset;
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    mkv_cuepoint    *entries;
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    int             num_entries;
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} mkv_cues;
63

    
64
typedef struct MatroskaMuxContext {
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    ebml_master     segment;
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    int64_t         segment_offset;
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    int64_t         segment_uid;
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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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    uint64_t        cluster_pts;
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    int64_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;
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77
    struct AVMD5    *md5_ctx;
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} MatroskaMuxContext;
79

    
80

    
81
/** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
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 * offset, 4 bytes for target EBML ID */
83
#define MAX_SEEKENTRY_SIZE 21
84

    
85
/** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
86
 * 8-byte uint max */
87
#define MAX_CUETRACKPOS_SIZE 22
88

    
89
/** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
90
#define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
91

    
92

    
93
static int ebml_id_size(unsigned int id)
94
{
95
    return (av_log2(id+1)-1)/7+1;
96
}
97

    
98
static void put_ebml_id(ByteIOContext *pb, unsigned int id)
99
{
100
    int i = ebml_id_size(id);
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    while (i--)
102
        put_byte(pb, id >> (i*8));
103
}
104

    
105
/**
106
 * Write an EBML size meaning "unknown size".
107
 *
108
 * @param bytes The number of bytes the size should occupy (maximum: 8).
109
 */
110
static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
111
{
112
    assert(bytes <= 8);
113
    put_byte(pb, 0x1ff >> bytes);
114
    while (--bytes)
115
        put_byte(pb, 0xff);
116
}
117

    
118
/**
119
 * Calculate how many bytes are needed to represent a given number in EBML.
120
 */
121
static int ebml_num_size(uint64_t num)
122
{
123
    int bytes = 1;
124
    while ((num+1) >> bytes*7) bytes++;
125
    return bytes;
126
}
127

    
128
/**
129
 * Write a number in EBML variable length format.
130
 *
131
 * @param bytes The number of bytes that need to be used to write the number.
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 *              If zero, any number of bytes can be used.
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 */
134
static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
135
{
136
    int i, needed_bytes = ebml_num_size(num);
137

    
138
    // sizes larger than this are currently undefined in EBML
139
    assert(num < (1ULL<<56)-1);
140

    
141
    if (bytes == 0)
142
        // don't care how many bytes are used, so use the min
143
        bytes = needed_bytes;
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    // the bytes needed to write the given size would exceed the bytes
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    // that we need to use, so write unknown size. This shouldn't happen.
146
    assert(bytes >= needed_bytes);
147

    
148
    num |= 1ULL << bytes*7;
149
    for (i = bytes - 1; i >= 0; i--)
150
        put_byte(pb, num >> i*8);
151
}
152

    
153
static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
154
{
155
    int i, bytes = 1;
156
    uint64_t tmp = val;
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    while (tmp>>=8) bytes++;
158

    
159
    put_ebml_id(pb, elementid);
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    put_ebml_num(pb, bytes, 0);
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    for (i = bytes - 1; i >= 0; i--)
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        put_byte(pb, val >> i*8);
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}
164

    
165
static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
166
{
167
    put_ebml_id(pb, elementid);
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    put_ebml_num(pb, 8, 0);
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    put_be64(pb, av_dbl2int(val));
170
}
171

    
172
static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
173
                            const uint8_t *buf, int size)
174
{
175
    put_ebml_id(pb, elementid);
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    put_ebml_num(pb, size, 0);
177
    put_buffer(pb, buf, size);
178
}
179

    
180
static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
181
{
182
    put_ebml_binary(pb, elementid, str, strlen(str));
183
}
184

    
185
/**
186
 * Writes a void element of a given size. Useful for reserving space in
187
 * the file to be written to later.
188
 *
189
 * @param size The number of bytes to reserve, which must be at least 2.
190
 */
191
static void put_ebml_void(ByteIOContext *pb, uint64_t size)
192
{
193
    int64_t currentpos = url_ftell(pb);
194

    
195
    assert(size >= 2);
196

    
197
    put_ebml_id(pb, EBML_ID_VOID);
198
    // we need to subtract the length needed to store the size from the
199
    // size we need to reserve so 2 cases, we use 8 bytes to store the
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    // size if possible, 1 byte otherwise
201
    if (size < 10)
202
        put_ebml_num(pb, size-1, 0);
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    else
204
        put_ebml_num(pb, size-9, 8);
205
    while(url_ftell(pb) < currentpos + size)
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        put_byte(pb, 0);
207
}
208

    
209
static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
210
{
211
    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 };
215
}
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static void end_ebml_master(ByteIOContext *pb, ebml_master master)
218
{
219
    int64_t pos = url_ftell(pb);
220

    
221
    if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
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        return;
223
    put_ebml_num(pb, pos - master.pos, master.sizebytes);
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    url_fseek(pb, pos, SEEK_SET);
225
}
226

    
227
static void put_xiph_size(ByteIOContext *pb, int size)
228
{
229
    int i;
230
    for (i = 0; i < size / 255; i++)
231
        put_byte(pb, 255);
232
    put_byte(pb, size % 255);
233
}
234

    
235
/**
236
 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
237
 * elements. If a maximum number of elements is specified, enough space
238
 * will be reserved at the current file location to write a seek head of
239
 * that size.
240
 *
241
 * @param segment_offset The absolute offset to the position in the file
242
 *                       where the segment begins.
243
 * @param numelements The maximum number of elements that will be indexed
244
 *                    by this seek head, 0 if unlimited.
245
 */
246
static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
247
{
248
    mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
249
    if (new_seekhead == NULL)
250
        return NULL;
251

    
252
    new_seekhead->segment_offset = segment_offset;
253

    
254
    if (numelements > 0) {
255
        new_seekhead->filepos = url_ftell(pb);
256
        // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
257
        // and size, and 3 bytes to guarantee that an EBML void element
258
        // will fit afterwards
259
        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
260
        new_seekhead->max_entries = numelements;
261
        put_ebml_void(pb, new_seekhead->reserved_size);
262
    }
263
    return new_seekhead;
264
}
265

    
266
static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
267
{
268
    mkv_seekhead_entry *entries = seekhead->entries;
269

    
270
    // don't store more elements than we reserved space for
271
    if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
272
        return -1;
273

    
274
    entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
275
    if (entries == NULL)
276
        return AVERROR(ENOMEM);
277

    
278
    entries[seekhead->num_entries  ].elementid = elementid;
279
    entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
280

    
281
    seekhead->entries = entries;
282
    return 0;
283
}
284

    
285
/**
286
 * Write the seek head to the file and free it. If a maximum number of
287
 * elements was specified to mkv_start_seekhead(), the seek head will
288
 * be written at the location reserved for it. Otherwise, it is written
289
 * at the current location in the file.
290
 *
291
 * @return The file offset where the seekhead was written,
292
 * -1 if an error occurred.
293
 */
294
static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
295
{
296
    ebml_master metaseek, seekentry;
297
    int64_t currentpos;
298
    int i;
299

    
300
    currentpos = url_ftell(pb);
301

    
302
    if (seekhead->reserved_size > 0)
303
        if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
304
            return -1;
305

    
306
    metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
307
    for (i = 0; i < seekhead->num_entries; i++) {
308
        mkv_seekhead_entry *entry = &seekhead->entries[i];
309

    
310
        seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
311

    
312
        put_ebml_id(pb, MATROSKA_ID_SEEKID);
313
        put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
314
        put_ebml_id(pb, entry->elementid);
315

    
316
        put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
317
        end_ebml_master(pb, seekentry);
318
    }
319
    end_ebml_master(pb, metaseek);
320

    
321
    if (seekhead->reserved_size > 0) {
322
        uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
323
        put_ebml_void(pb, remaining);
324
        url_fseek(pb, currentpos, SEEK_SET);
325

    
326
        currentpos = seekhead->filepos;
327
    }
328
    av_free(seekhead->entries);
329
    av_free(seekhead);
330

    
331
    return currentpos;
332
}
333

    
334
static mkv_cues * mkv_start_cues(int64_t segment_offset)
335
{
336
    mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
337
    if (cues == NULL)
338
        return NULL;
339

    
340
    cues->segment_offset = segment_offset;
341
    return cues;
342
}
343

    
344
static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, int64_t cluster_pos)
345
{
346
    mkv_cuepoint *entries = cues->entries;
347

    
348
    entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
349
    if (entries == NULL)
350
        return AVERROR(ENOMEM);
351

    
352
    entries[cues->num_entries  ].pts = pkt->pts;
353
    entries[cues->num_entries  ].tracknum = pkt->stream_index + 1;
354
    entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
355

    
356
    cues->entries = entries;
357
    return 0;
358
}
359

    
360
static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
361
{
362
    ebml_master cues_element;
363
    int64_t currentpos;
364
    int i, j;
365

    
366
    currentpos = url_ftell(pb);
367
    cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
368

    
369
    for (i = 0; i < cues->num_entries; i++) {
370
        ebml_master cuepoint, track_positions;
371
        mkv_cuepoint *entry = &cues->entries[i];
372
        uint64_t pts = entry->pts;
373

    
374
        cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
375
        put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
376

    
377
        // put all the entries from different tracks that have the exact same
378
        // timestamp into the same CuePoint
379
        for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
380
            track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
381
            put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
382
            put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
383
            end_ebml_master(pb, track_positions);
384
        }
385
        i += j - 1;
386
        end_ebml_master(pb, cuepoint);
387
    }
388
    end_ebml_master(pb, cues_element);
389

    
390
    av_free(cues->entries);
391
    av_free(cues);
392
    return currentpos;
393
}
394

    
395
static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
396
{
397
    uint8_t *header_start[3];
398
    int header_len[3];
399
    int first_header_size;
400
    int j;
401

    
402
    if (codec->codec_id == CODEC_ID_VORBIS)
403
        first_header_size = 30;
404
    else
405
        first_header_size = 42;
406

    
407
    if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
408
                              first_header_size, header_start, header_len) < 0) {
409
        av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
410
        return -1;
411
    }
412

    
413
    put_byte(pb, 2);                    // number packets - 1
414
    for (j = 0; j < 2; j++) {
415
        put_xiph_size(pb, header_len[j]);
416
    }
417
    for (j = 0; j < 3; j++)
418
        put_buffer(pb, header_start[j], header_len[j]);
419

    
420
    return 0;
421
}
422

    
423
static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
424
{
425
    int sri;
426

    
427
    if (codec->extradata_size < 2) {
428
        av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
429
        return;
430
    }
431

    
432
    sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
433
    if (sri > 12) {
434
        av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
435
        return;
436
    }
437
    *sample_rate = ff_mpeg4audio_sample_rates[sri];
438

    
439
    // if sbr, get output sample rate as well
440
    if (codec->extradata_size == 5) {
441
        sri = (codec->extradata[4] >> 3) & 0xF;
442
        if (sri > 12) {
443
            av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
444
            return;
445
        }
446
        *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
447
    }
448
}
449

    
450
static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
451
{
452
    ByteIOContext *dyn_cp;
453
    uint8_t *codecpriv;
454
    int ret, codecpriv_size;
455

    
456
    ret = url_open_dyn_buf(&dyn_cp);
457
    if(ret < 0)
458
        return ret;
459

    
460
    if (native_id) {
461
        if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
462
            ret = put_xiph_codecpriv(s, dyn_cp, codec);
463
        else if (codec->codec_id == CODEC_ID_FLAC)
464
            ret = ff_flac_write_header(dyn_cp, codec);
465
        else if (codec->codec_id == CODEC_ID_H264)
466
            ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
467
        else if (codec->extradata_size)
468
            put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
469
    } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
470
        if (qt_id) {
471
            if (!codec->codec_tag)
472
                codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
473
            if (codec->extradata_size)
474
                put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
475
        } else {
476
        if (!codec->codec_tag)
477
            codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
478
        if (!codec->codec_tag) {
479
            av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
480
            ret = -1;
481
        }
482

    
483
        ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
484
        }
485

    
486
    } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
487
        if (!codec->codec_tag)
488
            codec->codec_tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
489
        if (!codec->codec_tag) {
490
            av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
491
            ret = -1;
492
        }
493

    
494
        ff_put_wav_header(dyn_cp, codec);
495
    }
496

    
497
    codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
498
    if (codecpriv_size)
499
        put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
500
    av_free(codecpriv);
501
    return ret;
502
}
503

    
504
static int mkv_write_tracks(AVFormatContext *s)
505
{
506
    MatroskaMuxContext *mkv = s->priv_data;
507
    ByteIOContext *pb = s->pb;
508
    ebml_master tracks;
509
    int i, j, ret;
510

    
511
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
512
    if (ret < 0) return ret;
513

    
514
    tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
515
    for (i = 0; i < s->nb_streams; i++) {
516
        AVStream *st = s->streams[i];
517
        AVCodecContext *codec = st->codec;
518
        ebml_master subinfo, track;
519
        int native_id = 0;
520
        int qt_id = 0;
521
        int bit_depth = av_get_bits_per_sample(codec->codec_id);
522
        int sample_rate = codec->sample_rate;
523
        int output_sample_rate = 0;
524
        AVMetadataTag *tag;
525

    
526
        if (!bit_depth)
527
            bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
528

    
529
        if (codec->codec_id == CODEC_ID_AAC)
530
            get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
531

    
532
        track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
533
        put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
534
        put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
535
        put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
536
        put_ebml_float(pb, MATROSKA_ID_TRACKTIMECODESCALE, 1.0);
537

    
538
        if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
539
            put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
540
        tag = av_metadata_get(st->metadata, "language", NULL, 0);
541
        put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
542

    
543
        if (st->disposition)
544
            put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
545

    
546
        // look for a codec ID string specific to mkv to use,
547
        // if none are found, use AVI codes
548
        for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
549
            if (ff_mkv_codec_tags[j].id == codec->codec_id) {
550
                put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
551
                native_id = 1;
552
                break;
553
            }
554
        }
555

    
556
        switch (codec->codec_type) {
557
            case CODEC_TYPE_VIDEO:
558
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
559

    
560
                if (!native_id &&
561
                      ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
562
                    (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
563
                     || codec->codec_id == CODEC_ID_SVQ1
564
                     || codec->codec_id == CODEC_ID_SVQ3
565
                     || codec->codec_id == CODEC_ID_CINEPAK))
566
                    qt_id = 1;
567

    
568
                if (qt_id)
569
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
570
                else if (!native_id)
571
                    // if there is no mkv-specific codec ID, use VFW mode
572
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
573

    
574
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
575
                // XXX: interlace flag?
576
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
577
                put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
578
                if (st->sample_aspect_ratio.num) {
579
                    int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
580
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
581
                    put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
582
                }
583
                end_ebml_master(pb, subinfo);
584
                break;
585

    
586
            case CODEC_TYPE_AUDIO:
587
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
588

    
589
                if (!native_id)
590
                    // no mkv-specific ID, use ACM mode
591
                    put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
592

    
593
                subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
594
                put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
595
                put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
596
                if (output_sample_rate)
597
                    put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
598
                if (bit_depth)
599
                    put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
600
                end_ebml_master(pb, subinfo);
601
                break;
602

    
603
            case CODEC_TYPE_SUBTITLE:
604
                put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
605
                break;
606
            default:
607
                av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
608
                break;
609
        }
610
        ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
611
        if (ret < 0) return ret;
612

    
613
        end_ebml_master(pb, track);
614

    
615
        // ms precision is the de-facto standard timescale for mkv files
616
        av_set_pts_info(st, 64, 1, 1000);
617
    }
618
    end_ebml_master(pb, tracks);
619
    return 0;
620
}
621

    
622
static int mkv_write_chapters(AVFormatContext *s)
623
{
624
    MatroskaMuxContext *mkv = s->priv_data;
625
    ByteIOContext *pb = s->pb;
626
    ebml_master chapters, editionentry;
627
    AVRational scale = {1, 1E9};
628
    int i, ret;
629

    
630
    if (!s->nb_chapters)
631
        return 0;
632

    
633
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
634
    if (ret < 0) return ret;
635

    
636
    chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
637
    editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
638
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
639
    put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
640
    for (i = 0; i < s->nb_chapters; i++) {
641
        ebml_master chapteratom, chapterdisplay;
642
        AVChapter *c     = s->chapters[i];
643
        AVMetadataTag *t = NULL;
644

    
645
        chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
646
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
647
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
648
                      av_rescale_q(c->start, c->time_base, scale));
649
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
650
                      av_rescale_q(c->end,   c->time_base, scale));
651
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
652
        put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
653
        if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
654
            chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
655
            put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
656
            put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
657
            end_ebml_master(pb, chapterdisplay);
658
        }
659
        end_ebml_master(pb, chapteratom);
660
    }
661
    end_ebml_master(pb, editionentry);
662
    end_ebml_master(pb, chapters);
663
    return 0;
664
}
665

    
666
static int mkv_write_header(AVFormatContext *s)
667
{
668
    MatroskaMuxContext *mkv = s->priv_data;
669
    ByteIOContext *pb = s->pb;
670
    ebml_master ebml_header, segment_info;
671
    AVMetadataTag *tag;
672
    int ret;
673

    
674
    mkv->md5_ctx = av_mallocz(av_md5_size);
675
    av_md5_init(mkv->md5_ctx);
676

    
677
    ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
678
    put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
679
    put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
680
    put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
681
    put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
682
    put_ebml_string (pb, EBML_ID_DOCTYPE            ,  "matroska");
683
    put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
684
    put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
685
    end_ebml_master(pb, ebml_header);
686

    
687
    mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
688
    mkv->segment_offset = url_ftell(pb);
689

    
690
    // we write 2 seek heads - one at the end of the file to point to each
691
    // cluster, and one at the beginning to point to all other level one
692
    // elements (including the seek head at the end of the file), which
693
    // isn't more than 10 elements if we only write one of each other
694
    // currently defined level 1 element
695
    mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
696
    mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
697
    if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
698
        return AVERROR(ENOMEM);
699

    
700
    ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
701
    if (ret < 0) return ret;
702

    
703
    segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
704
    put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
705
    if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
706
        put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
707
    if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
708
        put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
709
        put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
710

    
711
        // reserve space to write the segment UID later
712
        mkv->segment_uid = url_ftell(pb);
713
        put_ebml_void(pb, 19);
714
    }
715

    
716
    // reserve space for the duration
717
    mkv->duration = 0;
718
    mkv->duration_offset = url_ftell(pb);
719
    put_ebml_void(pb, 11);                  // assumes double-precision float to be written
720
    end_ebml_master(pb, segment_info);
721

    
722
    ret = mkv_write_tracks(s);
723
    if (ret < 0) return ret;
724

    
725
    ret = mkv_write_chapters(s);
726
    if (ret < 0) return ret;
727

    
728
    if (url_is_streamed(s->pb))
729
        mkv_write_seekhead(pb, mkv->main_seekhead);
730

    
731
    mkv->cues = mkv_start_cues(mkv->segment_offset);
732
    if (mkv->cues == NULL)
733
        return AVERROR(ENOMEM);
734

    
735
    put_flush_packet(pb);
736
    return 0;
737
}
738

    
739
static int mkv_blockgroup_size(int pkt_size)
740
{
741
    int size = pkt_size + 4;
742
    size += ebml_num_size(size);
743
    size += 2;              // EBML ID for block and block duration
744
    size += 8;              // max size of block duration
745
    size += ebml_num_size(size);
746
    size += 1;              // blockgroup EBML ID
747
    return size;
748
}
749

    
750
static int ass_get_duration(const uint8_t *p)
751
{
752
    int sh, sm, ss, sc, eh, em, es, ec;
753
    uint64_t start, end;
754

    
755
    if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
756
               &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
757
        return 0;
758
    start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
759
    end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
760
    return end - start;
761
}
762

    
763
static int mkv_write_ass_blocks(AVFormatContext *s, AVPacket *pkt)
764
{
765
    MatroskaMuxContext *mkv = s->priv_data;
766
    ByteIOContext *pb = s->pb;
767
    int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
768
    uint8_t *start, *end, *data = pkt->data;
769
    ebml_master blockgroup;
770
    char buffer[2048];
771

    
772
    while (data_size) {
773
        int duration = ass_get_duration(data);
774
        max_duration = FFMAX(duration, max_duration);
775
        end = memchr(data, '\n', data_size);
776
        size = line_size = end ? end-data+1 : data_size;
777
        size -= end ? (end[-1]=='\r')+1 : 0;
778
        start = data;
779
        for (i=0; i<3; i++, start++)
780
            if (!(start = memchr(start, ',', size-(start-data))))
781
                return max_duration;
782
        size -= start - data;
783
        sscanf(data, "Dialogue: %d,", &layer);
784
        i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
785
                     s->streams[pkt->stream_index]->nb_frames++, layer);
786
        size = FFMIN(i+size, sizeof(buffer));
787
        memcpy(buffer+i, start, size-i);
788

    
789
        av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
790
               "pts %" PRId64 ", duration %d\n",
791
               url_ftell(pb), size, pkt->pts, duration);
792
        blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
793
        put_ebml_id(pb, MATROSKA_ID_BLOCK);
794
        put_ebml_num(pb, size+4, 0);
795
        put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
796
        put_be16(pb, pkt->pts - mkv->cluster_pts);
797
        put_byte(pb, 0);
798
        put_buffer(pb, buffer, size);
799
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
800
        end_ebml_master(pb, blockgroup);
801

    
802
        data += line_size;
803
        data_size -= line_size;
804
    }
805

    
806
    return max_duration;
807
}
808

    
809
static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
810
{
811
    MatroskaMuxContext *mkv = s->priv_data;
812
    ByteIOContext *pb = s->pb;
813
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
814
    uint8_t *data = NULL;
815
    int size = pkt->size;
816

    
817
    av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
818
           "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
819
           url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
820
    if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
821
        (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
822
        ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
823
    else
824
        data = pkt->data;
825
    put_ebml_id(pb, blockid);
826
    put_ebml_num(pb, size+4, 0);
827
    put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
828
    put_be16(pb, pkt->pts - mkv->cluster_pts);
829
    put_byte(pb, flags);
830
    put_buffer(pb, data, size);
831
    if (data != pkt->data)
832
        av_free(data);
833
}
834

    
835
static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
836
{
837
    MatroskaMuxContext *mkv = s->priv_data;
838
    ByteIOContext *pb = s->pb;
839
    AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
840
    int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
841
    int duration = pkt->duration;
842
    int ret;
843

    
844
    if (!mkv->cluster_pos) {
845
        ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
846
        if (ret < 0) return ret;
847

    
848
        mkv->cluster_pos = url_ftell(pb);
849
        mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
850
        put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
851
        mkv->cluster_pts = pkt->pts;
852
        av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
853
    }
854

    
855
    if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
856
        mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
857
    } else if (codec->codec_id == CODEC_ID_SSA) {
858
        duration = mkv_write_ass_blocks(s, pkt);
859
    } else {
860
        ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
861
        duration = pkt->convergence_duration;
862
        mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
863
        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
864
        end_ebml_master(pb, blockgroup);
865
    }
866

    
867
    if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
868
        ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
869
        if (ret < 0) return ret;
870
    }
871

    
872
    // start a new cluster every 5 MB or 5 sec
873
    if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
874
        av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
875
               " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
876
        end_ebml_master(pb, mkv->cluster);
877
        mkv->cluster_pos = 0;
878
    }
879

    
880
    mkv->duration = FFMAX(mkv->duration, pkt->pts + duration);
881
    return 0;
882
}
883

    
884
static int mkv_write_trailer(AVFormatContext *s)
885
{
886
    MatroskaMuxContext *mkv = s->priv_data;
887
    ByteIOContext *pb = s->pb;
888
    int64_t currentpos, second_seekhead, cuespos;
889
    int ret;
890

    
891
    end_ebml_master(pb, mkv->cluster);
892

    
893
    if (!url_is_streamed(pb)) {
894
        cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
895
        second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
896

    
897
        ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
898
        if (ret < 0) return ret;
899
        if (second_seekhead >= 0) {
900
            ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
901
            if (ret < 0) return ret;
902
        }
903
        mkv_write_seekhead(pb, mkv->main_seekhead);
904

    
905
        // update the duration
906
        av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
907
        currentpos = url_ftell(pb);
908
        url_fseek(pb, mkv->duration_offset, SEEK_SET);
909
        put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
910

    
911
        // write the md5sum of some frames as the segment UID
912
        if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
913
            uint8_t segment_uid[16];
914
            av_md5_final(mkv->md5_ctx, segment_uid);
915
            url_fseek(pb, mkv->segment_uid, SEEK_SET);
916
            put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
917
        }
918
        url_fseek(pb, currentpos, SEEK_SET);
919
    }
920

    
921
    end_ebml_master(pb, mkv->segment);
922
    av_free(mkv->md5_ctx);
923
    put_flush_packet(pb);
924
    return 0;
925
}
926

    
927
AVOutputFormat matroska_muxer = {
928
    "matroska",
929
    NULL_IF_CONFIG_SMALL("Matroska file format"),
930
    "video/x-matroska",
931
    "mkv",
932
    sizeof(MatroskaMuxContext),
933
    CODEC_ID_MP2,
934
    CODEC_ID_MPEG4,
935
    mkv_write_header,
936
    mkv_write_packet,
937
    mkv_write_trailer,
938
    .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
939
    .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
940
    .subtitle_codec = CODEC_ID_TEXT,
941
};
942

    
943
AVOutputFormat matroska_audio_muxer = {
944
    "matroska",
945
    NULL_IF_CONFIG_SMALL("Matroska file format"),
946
    "audio/x-matroska",
947
    "mka",
948
    sizeof(MatroskaMuxContext),
949
    CODEC_ID_MP2,
950
    CODEC_ID_NONE,
951
    mkv_write_header,
952
    mkv_write_packet,
953
    mkv_write_trailer,
954
    .flags = AVFMT_GLOBALHEADER,
955
    .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
956
};