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1
/*
2
 * MXF demuxer.
3
 * Copyright (c) 2006 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
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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
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 * 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
/*
23
 * References
24
 * SMPTE 336M KLV Data Encoding Protocol Using Key-Length-Value
25
 * SMPTE 377M MXF File Format Specifications
26
 * SMPTE 378M Operational Pattern 1a
27
 * SMPTE 379M MXF Generic Container
28
 * SMPTE 381M Mapping MPEG Streams into the MXF Generic Container
29
 * SMPTE 382M Mapping AES3 and Broadcast Wave Audio into the MXF Generic Container
30
 * SMPTE 383M Mapping DV-DIF Data to the MXF Generic Container
31
 *
32
 * Principle
33
 * Search for Track numbers which will identify essence element KLV packets.
34
 * Search for SourcePackage which define tracks which contains Track numbers.
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 * Material Package contains tracks with reference to SourcePackage tracks.
36
 * Search for Descriptors (Picture, Sound) which contains codec info and parameters.
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 * Assign Descriptors to correct Tracks.
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 *
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 * Metadata reading functions read Local Tags, get InstanceUID(0x3C0A) then add MetaDataSet to MXFContext.
40
 * Metadata parsing resolves Strong References to objects.
41
 *
42
 * Simple demuxer, only OP1A supported and some files might not work at all.
43
 * Only tracks with associated descriptors will be decoded. "Highly Desirable" SMPTE 377M D.1
44
 */
45

    
46
//#define DEBUG
47

    
48
#include "libavutil/aes.h"
49
#include "libavcodec/bytestream.h"
50
#include "avformat.h"
51
#include "mxf.h"
52

    
53
typedef struct {
54
    UID uid;
55
    enum MXFMetadataSetType type;
56
    UID source_container_ul;
57
} MXFCryptoContext;
58

    
59
typedef struct {
60
    UID uid;
61
    enum MXFMetadataSetType type;
62
    UID source_package_uid;
63
    UID data_definition_ul;
64
    int64_t duration;
65
    int64_t start_position;
66
    int source_track_id;
67
} MXFStructuralComponent;
68

    
69
typedef struct {
70
    UID uid;
71
    enum MXFMetadataSetType type;
72
    UID data_definition_ul;
73
    UID *structural_components_refs;
74
    int structural_components_count;
75
    int64_t duration;
76
} MXFSequence;
77

    
78
typedef struct {
79
    UID uid;
80
    enum MXFMetadataSetType type;
81
    MXFSequence *sequence; /* mandatory, and only one */
82
    UID sequence_ref;
83
    int track_id;
84
    uint8_t track_number[4];
85
    AVRational edit_rate;
86
} MXFTrack;
87

    
88
typedef struct {
89
    UID uid;
90
    enum MXFMetadataSetType type;
91
    UID essence_container_ul;
92
    UID essence_codec_ul;
93
    AVRational sample_rate;
94
    AVRational aspect_ratio;
95
    int width;
96
    int height;
97
    int channels;
98
    int bits_per_sample;
99
    UID *sub_descriptors_refs;
100
    int sub_descriptors_count;
101
    int linked_track_id;
102
    uint8_t *extradata;
103
    int extradata_size;
104
    enum PixelFormat pix_fmt;
105
} MXFDescriptor;
106

    
107
typedef struct {
108
    UID uid;
109
    enum MXFMetadataSetType type;
110
} MXFIndexTableSegment;
111

    
112
typedef struct {
113
    UID uid;
114
    enum MXFMetadataSetType type;
115
    UID package_uid;
116
    UID *tracks_refs;
117
    int tracks_count;
118
    MXFDescriptor *descriptor; /* only one */
119
    UID descriptor_ref;
120
} MXFPackage;
121

    
122
typedef struct {
123
    UID uid;
124
    enum MXFMetadataSetType type;
125
} MXFMetadataSet;
126

    
127
typedef struct {
128
    UID *packages_refs;
129
    int packages_count;
130
    MXFMetadataSet **metadata_sets;
131
    int metadata_sets_count;
132
    AVFormatContext *fc;
133
    struct AVAES *aesc;
134
    uint8_t *local_tags;
135
    int local_tags_count;
136
} MXFContext;
137

    
138
enum MXFWrappingScheme {
139
    Frame,
140
    Clip,
141
};
142

    
143
typedef int MXFMetadataReadFunc(void *arg, AVIOContext *pb, int tag, int size, UID uid);
144

    
145
typedef struct {
146
    const UID key;
147
    MXFMetadataReadFunc *read;
148
    int ctx_size;
149
    enum MXFMetadataSetType type;
150
} MXFMetadataReadTableEntry;
151

    
152
/* partial keys to match */
153
static const uint8_t mxf_header_partition_pack_key[]       = { 0x06,0x0e,0x2b,0x34,0x02,0x05,0x01,0x01,0x0d,0x01,0x02,0x01,0x01,0x02 };
154
static const uint8_t mxf_essence_element_key[]             = { 0x06,0x0e,0x2b,0x34,0x01,0x02,0x01,0x01,0x0d,0x01,0x03,0x01 };
155
static const uint8_t mxf_klv_key[]                         = { 0x06,0x0e,0x2b,0x34 };
156
/* complete keys to match */
157
static const uint8_t mxf_crypto_source_container_ul[]      = { 0x06,0x0e,0x2b,0x34,0x01,0x01,0x01,0x09,0x06,0x01,0x01,0x02,0x02,0x00,0x00,0x00 };
158
static const uint8_t mxf_encrypted_triplet_key[]           = { 0x06,0x0e,0x2b,0x34,0x02,0x04,0x01,0x07,0x0d,0x01,0x03,0x01,0x02,0x7e,0x01,0x00 };
159
static const uint8_t mxf_encrypted_essence_container[]     = { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x07,0x0d,0x01,0x03,0x01,0x02,0x0b,0x01,0x00 };
160
static const uint8_t mxf_sony_mpeg4_extradata[]            = { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x01,0x0e,0x06,0x06,0x02,0x02,0x01,0x00,0x00 };
161

    
162
#define IS_KLV_KEY(x, y) (!memcmp(x, y, sizeof(y)))
163

    
164
static int64_t klv_decode_ber_length(AVIOContext *pb)
165
{
166
    uint64_t size = avio_r8(pb);
167
    if (size & 0x80) { /* long form */
168
        int bytes_num = size & 0x7f;
169
        /* SMPTE 379M 5.3.4 guarantee that bytes_num must not exceed 8 bytes */
170
        if (bytes_num > 8)
171
            return -1;
172
        size = 0;
173
        while (bytes_num--)
174
            size = size << 8 | avio_r8(pb);
175
    }
176
    return size;
177
}
178

    
179
static int mxf_read_sync(AVIOContext *pb, const uint8_t *key, unsigned size)
180
{
181
    int i, b;
182
    for (i = 0; i < size && !url_feof(pb); i++) {
183
        b = avio_r8(pb);
184
        if (b == key[0])
185
            i = 0;
186
        else if (b != key[i])
187
            i = -1;
188
    }
189
    return i == size;
190
}
191

    
192
static int klv_read_packet(KLVPacket *klv, AVIOContext *pb)
193
{
194
    if (!mxf_read_sync(pb, mxf_klv_key, 4))
195
        return -1;
196
    klv->offset = url_ftell(pb) - 4;
197
    memcpy(klv->key, mxf_klv_key, 4);
198
    avio_read(pb, klv->key + 4, 12);
199
    klv->length = klv_decode_ber_length(pb);
200
    return klv->length == -1 ? -1 : 0;
201
}
202

    
203
static int mxf_get_stream_index(AVFormatContext *s, KLVPacket *klv)
204
{
205
    int i;
206

    
207
    for (i = 0; i < s->nb_streams; i++) {
208
        MXFTrack *track = s->streams[i]->priv_data;
209
        /* SMPTE 379M 7.3 */
210
        if (!memcmp(klv->key + sizeof(mxf_essence_element_key), track->track_number, sizeof(track->track_number)))
211
            return i;
212
    }
213
    /* return 0 if only one stream, for OP Atom files with 0 as track number */
214
    return s->nb_streams == 1 ? 0 : -1;
215
}
216

    
217
/* XXX: use AVBitStreamFilter */
218
static int mxf_get_d10_aes3_packet(AVIOContext *pb, AVStream *st, AVPacket *pkt, int64_t length)
219
{
220
    const uint8_t *buf_ptr, *end_ptr;
221
    uint8_t *data_ptr;
222
    int i;
223

    
224
    if (length > 61444) /* worst case PAL 1920 samples 8 channels */
225
        return -1;
226
    av_new_packet(pkt, length);
227
    avio_read(pb, pkt->data, length);
228
    data_ptr = pkt->data;
229
    end_ptr = pkt->data + length;
230
    buf_ptr = pkt->data + 4; /* skip SMPTE 331M header */
231
    for (; buf_ptr < end_ptr; ) {
232
        for (i = 0; i < st->codec->channels; i++) {
233
            uint32_t sample = bytestream_get_le32(&buf_ptr);
234
            if (st->codec->bits_per_coded_sample == 24)
235
                bytestream_put_le24(&data_ptr, (sample >> 4) & 0xffffff);
236
            else
237
                bytestream_put_le16(&data_ptr, (sample >> 12) & 0xffff);
238
        }
239
        buf_ptr += 32 - st->codec->channels*4; // always 8 channels stored SMPTE 331M
240
    }
241
    pkt->size = data_ptr - pkt->data;
242
    return 0;
243
}
244

    
245
static int mxf_decrypt_triplet(AVFormatContext *s, AVPacket *pkt, KLVPacket *klv)
246
{
247
    static const uint8_t checkv[16] = {0x43, 0x48, 0x55, 0x4b, 0x43, 0x48, 0x55, 0x4b, 0x43, 0x48, 0x55, 0x4b, 0x43, 0x48, 0x55, 0x4b};
248
    MXFContext *mxf = s->priv_data;
249
    AVIOContext *pb = s->pb;
250
    int64_t end = url_ftell(pb) + klv->length;
251
    uint64_t size;
252
    uint64_t orig_size;
253
    uint64_t plaintext_size;
254
    uint8_t ivec[16];
255
    uint8_t tmpbuf[16];
256
    int index;
257

    
258
    if (!mxf->aesc && s->key && s->keylen == 16) {
259
        mxf->aesc = av_malloc(av_aes_size);
260
        if (!mxf->aesc)
261
            return -1;
262
        av_aes_init(mxf->aesc, s->key, 128, 1);
263
    }
264
    // crypto context
265
    url_fskip(pb, klv_decode_ber_length(pb));
266
    // plaintext offset
267
    klv_decode_ber_length(pb);
268
    plaintext_size = avio_rb64(pb);
269
    // source klv key
270
    klv_decode_ber_length(pb);
271
    avio_read(pb, klv->key, 16);
272
    if (!IS_KLV_KEY(klv, mxf_essence_element_key))
273
        return -1;
274
    index = mxf_get_stream_index(s, klv);
275
    if (index < 0)
276
        return -1;
277
    // source size
278
    klv_decode_ber_length(pb);
279
    orig_size = avio_rb64(pb);
280
    if (orig_size < plaintext_size)
281
        return -1;
282
    // enc. code
283
    size = klv_decode_ber_length(pb);
284
    if (size < 32 || size - 32 < orig_size)
285
        return -1;
286
    avio_read(pb, ivec, 16);
287
    avio_read(pb, tmpbuf, 16);
288
    if (mxf->aesc)
289
        av_aes_crypt(mxf->aesc, tmpbuf, tmpbuf, 1, ivec, 1);
290
    if (memcmp(tmpbuf, checkv, 16))
291
        av_log(s, AV_LOG_ERROR, "probably incorrect decryption key\n");
292
    size -= 32;
293
    av_get_packet(pb, pkt, size);
294
    size -= plaintext_size;
295
    if (mxf->aesc)
296
        av_aes_crypt(mxf->aesc, &pkt->data[plaintext_size],
297
                     &pkt->data[plaintext_size], size >> 4, ivec, 1);
298
    pkt->size = orig_size;
299
    pkt->stream_index = index;
300
    url_fskip(pb, end - url_ftell(pb));
301
    return 0;
302
}
303

    
304
static int mxf_read_packet(AVFormatContext *s, AVPacket *pkt)
305
{
306
    KLVPacket klv;
307

    
308
    while (!url_feof(s->pb)) {
309
        if (klv_read_packet(&klv, s->pb) < 0)
310
            return -1;
311
        PRINT_KEY(s, "read packet", klv.key);
312
        av_dlog(s, "size %lld offset %#llx\n", klv.length, klv.offset);
313
        if (IS_KLV_KEY(klv.key, mxf_encrypted_triplet_key)) {
314
            int res = mxf_decrypt_triplet(s, pkt, &klv);
315
            if (res < 0) {
316
                av_log(s, AV_LOG_ERROR, "invalid encoded triplet\n");
317
                return -1;
318
            }
319
            return 0;
320
        }
321
        if (IS_KLV_KEY(klv.key, mxf_essence_element_key)) {
322
            int index = mxf_get_stream_index(s, &klv);
323
            if (index < 0) {
324
                av_log(s, AV_LOG_ERROR, "error getting stream index %d\n", AV_RB32(klv.key+12));
325
                goto skip;
326
            }
327
            if (s->streams[index]->discard == AVDISCARD_ALL)
328
                goto skip;
329
            /* check for 8 channels AES3 element */
330
            if (klv.key[12] == 0x06 && klv.key[13] == 0x01 && klv.key[14] == 0x10) {
331
                if (mxf_get_d10_aes3_packet(s->pb, s->streams[index], pkt, klv.length) < 0) {
332
                    av_log(s, AV_LOG_ERROR, "error reading D-10 aes3 frame\n");
333
                    return -1;
334
                }
335
            } else
336
                av_get_packet(s->pb, pkt, klv.length);
337
            pkt->stream_index = index;
338
            pkt->pos = klv.offset;
339
            return 0;
340
        } else
341
        skip:
342
            url_fskip(s->pb, klv.length);
343
    }
344
    return AVERROR_EOF;
345
}
346

    
347
static int mxf_read_primer_pack(void *arg, AVIOContext *pb, int tag, int size, UID uid)
348
{
349
    MXFContext *mxf = arg;
350
    int item_num = avio_rb32(pb);
351
    int item_len = avio_rb32(pb);
352

    
353
    if (item_len != 18) {
354
        av_log(mxf->fc, AV_LOG_ERROR, "unsupported primer pack item length\n");
355
        return -1;
356
    }
357
    if (item_num > UINT_MAX / item_len)
358
        return -1;
359
    mxf->local_tags_count = item_num;
360
    mxf->local_tags = av_malloc(item_num*item_len);
361
    if (!mxf->local_tags)
362
        return -1;
363
    avio_read(pb, mxf->local_tags, item_num*item_len);
364
    return 0;
365
}
366

    
367
static int mxf_add_metadata_set(MXFContext *mxf, void *metadata_set)
368
{
369
    if (mxf->metadata_sets_count+1 >= UINT_MAX / sizeof(*mxf->metadata_sets))
370
        return AVERROR(ENOMEM);
371
    mxf->metadata_sets = av_realloc(mxf->metadata_sets, (mxf->metadata_sets_count + 1) * sizeof(*mxf->metadata_sets));
372
    if (!mxf->metadata_sets)
373
        return -1;
374
    mxf->metadata_sets[mxf->metadata_sets_count] = metadata_set;
375
    mxf->metadata_sets_count++;
376
    return 0;
377
}
378

    
379
static int mxf_read_cryptographic_context(void *arg, AVIOContext *pb, int tag, int size, UID uid)
380
{
381
    MXFCryptoContext *cryptocontext = arg;
382
    if (size != 16)
383
        return -1;
384
    if (IS_KLV_KEY(uid, mxf_crypto_source_container_ul))
385
        avio_read(pb, cryptocontext->source_container_ul, 16);
386
    return 0;
387
}
388

    
389
static int mxf_read_content_storage(void *arg, AVIOContext *pb, int tag, int size, UID uid)
390
{
391
    MXFContext *mxf = arg;
392
    switch (tag) {
393
    case 0x1901:
394
        mxf->packages_count = avio_rb32(pb);
395
        if (mxf->packages_count >= UINT_MAX / sizeof(UID))
396
            return -1;
397
        mxf->packages_refs = av_malloc(mxf->packages_count * sizeof(UID));
398
        if (!mxf->packages_refs)
399
            return -1;
400
        url_fskip(pb, 4); /* useless size of objects, always 16 according to specs */
401
        avio_read(pb, (uint8_t *)mxf->packages_refs, mxf->packages_count * sizeof(UID));
402
        break;
403
    }
404
    return 0;
405
}
406

    
407
static int mxf_read_source_clip(void *arg, AVIOContext *pb, int tag, int size, UID uid)
408
{
409
    MXFStructuralComponent *source_clip = arg;
410
    switch(tag) {
411
    case 0x0202:
412
        source_clip->duration = avio_rb64(pb);
413
        break;
414
    case 0x1201:
415
        source_clip->start_position = avio_rb64(pb);
416
        break;
417
    case 0x1101:
418
        /* UMID, only get last 16 bytes */
419
        url_fskip(pb, 16);
420
        avio_read(pb, source_clip->source_package_uid, 16);
421
        break;
422
    case 0x1102:
423
        source_clip->source_track_id = avio_rb32(pb);
424
        break;
425
    }
426
    return 0;
427
}
428

    
429
static int mxf_read_material_package(void *arg, AVIOContext *pb, int tag, int size, UID uid)
430
{
431
    MXFPackage *package = arg;
432
    switch(tag) {
433
    case 0x4403:
434
        package->tracks_count = avio_rb32(pb);
435
        if (package->tracks_count >= UINT_MAX / sizeof(UID))
436
            return -1;
437
        package->tracks_refs = av_malloc(package->tracks_count * sizeof(UID));
438
        if (!package->tracks_refs)
439
            return -1;
440
        url_fskip(pb, 4); /* useless size of objects, always 16 according to specs */
441
        avio_read(pb, (uint8_t *)package->tracks_refs, package->tracks_count * sizeof(UID));
442
        break;
443
    }
444
    return 0;
445
}
446

    
447
static int mxf_read_track(void *arg, AVIOContext *pb, int tag, int size, UID uid)
448
{
449
    MXFTrack *track = arg;
450
    switch(tag) {
451
    case 0x4801:
452
        track->track_id = avio_rb32(pb);
453
        break;
454
    case 0x4804:
455
        avio_read(pb, track->track_number, 4);
456
        break;
457
    case 0x4B01:
458
        track->edit_rate.den = avio_rb32(pb);
459
        track->edit_rate.num = avio_rb32(pb);
460
        break;
461
    case 0x4803:
462
        avio_read(pb, track->sequence_ref, 16);
463
        break;
464
    }
465
    return 0;
466
}
467

    
468
static int mxf_read_sequence(void *arg, AVIOContext *pb, int tag, int size, UID uid)
469
{
470
    MXFSequence *sequence = arg;
471
    switch(tag) {
472
    case 0x0202:
473
        sequence->duration = avio_rb64(pb);
474
        break;
475
    case 0x0201:
476
        avio_read(pb, sequence->data_definition_ul, 16);
477
        break;
478
    case 0x1001:
479
        sequence->structural_components_count = avio_rb32(pb);
480
        if (sequence->structural_components_count >= UINT_MAX / sizeof(UID))
481
            return -1;
482
        sequence->structural_components_refs = av_malloc(sequence->structural_components_count * sizeof(UID));
483
        if (!sequence->structural_components_refs)
484
            return -1;
485
        url_fskip(pb, 4); /* useless size of objects, always 16 according to specs */
486
        avio_read(pb, (uint8_t *)sequence->structural_components_refs, sequence->structural_components_count * sizeof(UID));
487
        break;
488
    }
489
    return 0;
490
}
491

    
492
static int mxf_read_source_package(void *arg, AVIOContext *pb, int tag, int size, UID uid)
493
{
494
    MXFPackage *package = arg;
495
    switch(tag) {
496
    case 0x4403:
497
        package->tracks_count = avio_rb32(pb);
498
        if (package->tracks_count >= UINT_MAX / sizeof(UID))
499
            return -1;
500
        package->tracks_refs = av_malloc(package->tracks_count * sizeof(UID));
501
        if (!package->tracks_refs)
502
            return -1;
503
        url_fskip(pb, 4); /* useless size of objects, always 16 according to specs */
504
        avio_read(pb, (uint8_t *)package->tracks_refs, package->tracks_count * sizeof(UID));
505
        break;
506
    case 0x4401:
507
        /* UMID, only get last 16 bytes */
508
        url_fskip(pb, 16);
509
        avio_read(pb, package->package_uid, 16);
510
        break;
511
    case 0x4701:
512
        avio_read(pb, package->descriptor_ref, 16);
513
        break;
514
    }
515
    return 0;
516
}
517

    
518
static int mxf_read_index_table_segment(void *arg, AVIOContext *pb, int tag, int size, UID uid)
519
{
520
    switch(tag) {
521
    case 0x3F05: av_dlog(NULL, "EditUnitByteCount %d\n", avio_rb32(pb)); break;
522
    case 0x3F06: av_dlog(NULL, "IndexSID %d\n", avio_rb32(pb)); break;
523
    case 0x3F07: av_dlog(NULL, "BodySID %d\n", avio_rb32(pb)); break;
524
    case 0x3F0B: av_dlog(NULL, "IndexEditRate %d/%d\n", avio_rb32(pb), avio_rb32(pb)); break;
525
    case 0x3F0C: av_dlog(NULL, "IndexStartPosition %lld\n", avio_rb64(pb)); break;
526
    case 0x3F0D: av_dlog(NULL, "IndexDuration %lld\n", avio_rb64(pb)); break;
527
    }
528
    return 0;
529
}
530

    
531
static void mxf_read_pixel_layout(AVIOContext *pb, MXFDescriptor *descriptor)
532
{
533
    int code, value, ofs = 0;
534
    char layout[16] = {0};
535

    
536
    do {
537
        code = avio_r8(pb);
538
        value = avio_r8(pb);
539
        av_dlog(NULL, "pixel layout: code %#x\n", code);
540

    
541
        if (ofs < 16) {
542
            layout[ofs++] = code;
543
            layout[ofs++] = value;
544
        }
545
    } while (code != 0); /* SMPTE 377M E.2.46 */
546

    
547
    ff_mxf_decode_pixel_layout(layout, &descriptor->pix_fmt);
548
}
549

    
550
static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int size, UID uid)
551
{
552
    MXFDescriptor *descriptor = arg;
553
    switch(tag) {
554
    case 0x3F01:
555
        descriptor->sub_descriptors_count = avio_rb32(pb);
556
        if (descriptor->sub_descriptors_count >= UINT_MAX / sizeof(UID))
557
            return -1;
558
        descriptor->sub_descriptors_refs = av_malloc(descriptor->sub_descriptors_count * sizeof(UID));
559
        if (!descriptor->sub_descriptors_refs)
560
            return -1;
561
        url_fskip(pb, 4); /* useless size of objects, always 16 according to specs */
562
        avio_read(pb, (uint8_t *)descriptor->sub_descriptors_refs, descriptor->sub_descriptors_count * sizeof(UID));
563
        break;
564
    case 0x3004:
565
        avio_read(pb, descriptor->essence_container_ul, 16);
566
        break;
567
    case 0x3006:
568
        descriptor->linked_track_id = avio_rb32(pb);
569
        break;
570
    case 0x3201: /* PictureEssenceCoding */
571
        avio_read(pb, descriptor->essence_codec_ul, 16);
572
        break;
573
    case 0x3203:
574
        descriptor->width = avio_rb32(pb);
575
        break;
576
    case 0x3202:
577
        descriptor->height = avio_rb32(pb);
578
        break;
579
    case 0x320E:
580
        descriptor->aspect_ratio.num = avio_rb32(pb);
581
        descriptor->aspect_ratio.den = avio_rb32(pb);
582
        break;
583
    case 0x3D03:
584
        descriptor->sample_rate.num = avio_rb32(pb);
585
        descriptor->sample_rate.den = avio_rb32(pb);
586
        break;
587
    case 0x3D06: /* SoundEssenceCompression */
588
        avio_read(pb, descriptor->essence_codec_ul, 16);
589
        break;
590
    case 0x3D07:
591
        descriptor->channels = avio_rb32(pb);
592
        break;
593
    case 0x3D01:
594
        descriptor->bits_per_sample = avio_rb32(pb);
595
        break;
596
    case 0x3401:
597
        mxf_read_pixel_layout(pb, descriptor);
598
        break;
599
    default:
600
        /* Private uid used by SONY C0023S01.mxf */
601
        if (IS_KLV_KEY(uid, mxf_sony_mpeg4_extradata)) {
602
            descriptor->extradata = av_malloc(size);
603
            if (!descriptor->extradata)
604
                return -1;
605
            descriptor->extradata_size = size;
606
            avio_read(pb, descriptor->extradata, size);
607
        }
608
        break;
609
    }
610
    return 0;
611
}
612

    
613
/*
614
 * Match an uid independently of the version byte and up to len common bytes
615
 * Returns: boolean
616
 */
617
static int mxf_match_uid(const UID key, const UID uid, int len)
618
{
619
    int i;
620
    for (i = 0; i < len; i++) {
621
        if (i != 7 && key[i] != uid[i])
622
            return 0;
623
    }
624
    return 1;
625
}
626

    
627
static const MXFCodecUL *mxf_get_codec_ul(const MXFCodecUL *uls, UID *uid)
628
{
629
    while (uls->uid[0]) {
630
        if(mxf_match_uid(uls->uid, *uid, uls->matching_len))
631
            break;
632
        uls++;
633
    }
634
    return uls;
635
}
636

    
637
static void *mxf_resolve_strong_ref(MXFContext *mxf, UID *strong_ref, enum MXFMetadataSetType type)
638
{
639
    int i;
640

    
641
    if (!strong_ref)
642
        return NULL;
643
    for (i = 0; i < mxf->metadata_sets_count; i++) {
644
        if (!memcmp(*strong_ref, mxf->metadata_sets[i]->uid, 16) &&
645
            (type == AnyType || mxf->metadata_sets[i]->type == type)) {
646
            return mxf->metadata_sets[i];
647
        }
648
    }
649
    return NULL;
650
}
651

    
652
static const MXFCodecUL mxf_essence_container_uls[] = {
653
    // video essence container uls
654
    { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x02,0x0D,0x01,0x03,0x01,0x02,0x04,0x60,0x01 }, 14, CODEC_ID_MPEG2VIDEO }, /* MPEG-ES Frame wrapped */
655
    { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x02,0x41,0x01 }, 14,    CODEC_ID_DVVIDEO }, /* DV 625 25mbps */
656
    // sound essence container uls
657
    { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x06,0x01,0x00 }, 14, CODEC_ID_PCM_S16LE }, /* BWF Frame wrapped */
658
    { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x02,0x0D,0x01,0x03,0x01,0x02,0x04,0x40,0x01 }, 14,       CODEC_ID_MP2 }, /* MPEG-ES Frame wrapped, 0x40 ??? stream id */
659
    { { 0x06,0x0E,0x2B,0x34,0x04,0x01,0x01,0x01,0x0D,0x01,0x03,0x01,0x02,0x01,0x01,0x01 }, 14, CODEC_ID_PCM_S16LE }, /* D-10 Mapping 50Mbps PAL Extended Template */
660
    { { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },  0,      CODEC_ID_NONE },
661
};
662

    
663
static int mxf_parse_structural_metadata(MXFContext *mxf)
664
{
665
    MXFPackage *material_package = NULL;
666
    MXFPackage *temp_package = NULL;
667
    int i, j, k;
668

    
669
    av_dlog(mxf->fc, "metadata sets count %d\n", mxf->metadata_sets_count);
670
    /* TODO: handle multiple material packages (OP3x) */
671
    for (i = 0; i < mxf->packages_count; i++) {
672
        material_package = mxf_resolve_strong_ref(mxf, &mxf->packages_refs[i], MaterialPackage);
673
        if (material_package) break;
674
    }
675
    if (!material_package) {
676
        av_log(mxf->fc, AV_LOG_ERROR, "no material package found\n");
677
        return -1;
678
    }
679

    
680
    for (i = 0; i < material_package->tracks_count; i++) {
681
        MXFPackage *source_package = NULL;
682
        MXFTrack *material_track = NULL;
683
        MXFTrack *source_track = NULL;
684
        MXFTrack *temp_track = NULL;
685
        MXFDescriptor *descriptor = NULL;
686
        MXFStructuralComponent *component = NULL;
687
        UID *essence_container_ul = NULL;
688
        const MXFCodecUL *codec_ul = NULL;
689
        const MXFCodecUL *container_ul = NULL;
690
        AVStream *st;
691

    
692
        if (!(material_track = mxf_resolve_strong_ref(mxf, &material_package->tracks_refs[i], Track))) {
693
            av_log(mxf->fc, AV_LOG_ERROR, "could not resolve material track strong ref\n");
694
            continue;
695
        }
696

    
697
        if (!(material_track->sequence = mxf_resolve_strong_ref(mxf, &material_track->sequence_ref, Sequence))) {
698
            av_log(mxf->fc, AV_LOG_ERROR, "could not resolve material track sequence strong ref\n");
699
            continue;
700
        }
701

    
702
        /* TODO: handle multiple source clips */
703
        for (j = 0; j < material_track->sequence->structural_components_count; j++) {
704
            /* TODO: handle timecode component */
705
            component = mxf_resolve_strong_ref(mxf, &material_track->sequence->structural_components_refs[j], SourceClip);
706
            if (!component)
707
                continue;
708

    
709
            for (k = 0; k < mxf->packages_count; k++) {
710
                temp_package = mxf_resolve_strong_ref(mxf, &mxf->packages_refs[k], SourcePackage);
711
                if (!temp_package)
712
                    continue;
713
                if (!memcmp(temp_package->package_uid, component->source_package_uid, 16)) {
714
                    source_package = temp_package;
715
                    break;
716
                }
717
            }
718
            if (!source_package) {
719
                av_log(mxf->fc, AV_LOG_ERROR, "material track %d: no corresponding source package found\n", material_track->track_id);
720
                break;
721
            }
722
            for (k = 0; k < source_package->tracks_count; k++) {
723
                if (!(temp_track = mxf_resolve_strong_ref(mxf, &source_package->tracks_refs[k], Track))) {
724
                    av_log(mxf->fc, AV_LOG_ERROR, "could not resolve source track strong ref\n");
725
                    return -1;
726
                }
727
                if (temp_track->track_id == component->source_track_id) {
728
                    source_track = temp_track;
729
                    break;
730
                }
731
            }
732
            if (!source_track) {
733
                av_log(mxf->fc, AV_LOG_ERROR, "material track %d: no corresponding source track found\n", material_track->track_id);
734
                break;
735
            }
736
        }
737
        if (!source_track)
738
            continue;
739

    
740
        st = av_new_stream(mxf->fc, source_track->track_id);
741
        if (!st) {
742
            av_log(mxf->fc, AV_LOG_ERROR, "could not allocate stream\n");
743
            return -1;
744
        }
745
        st->priv_data = source_track;
746
        st->duration = component->duration;
747
        if (st->duration == -1)
748
            st->duration = AV_NOPTS_VALUE;
749
        st->start_time = component->start_position;
750
        av_set_pts_info(st, 64, material_track->edit_rate.num, material_track->edit_rate.den);
751

    
752
        if (!(source_track->sequence = mxf_resolve_strong_ref(mxf, &source_track->sequence_ref, Sequence))) {
753
            av_log(mxf->fc, AV_LOG_ERROR, "could not resolve source track sequence strong ref\n");
754
            return -1;
755
        }
756

    
757
        PRINT_KEY(mxf->fc, "data definition   ul", source_track->sequence->data_definition_ul);
758
        codec_ul = mxf_get_codec_ul(ff_mxf_data_definition_uls, &source_track->sequence->data_definition_ul);
759
        st->codec->codec_type = codec_ul->id;
760

    
761
        source_package->descriptor = mxf_resolve_strong_ref(mxf, &source_package->descriptor_ref, AnyType);
762
        if (source_package->descriptor) {
763
            if (source_package->descriptor->type == MultipleDescriptor) {
764
                for (j = 0; j < source_package->descriptor->sub_descriptors_count; j++) {
765
                    MXFDescriptor *sub_descriptor = mxf_resolve_strong_ref(mxf, &source_package->descriptor->sub_descriptors_refs[j], Descriptor);
766

    
767
                    if (!sub_descriptor) {
768
                        av_log(mxf->fc, AV_LOG_ERROR, "could not resolve sub descriptor strong ref\n");
769
                        continue;
770
                    }
771
                    if (sub_descriptor->linked_track_id == source_track->track_id) {
772
                        descriptor = sub_descriptor;
773
                        break;
774
                    }
775
                }
776
            } else if (source_package->descriptor->type == Descriptor)
777
                descriptor = source_package->descriptor;
778
        }
779
        if (!descriptor) {
780
            av_log(mxf->fc, AV_LOG_INFO, "source track %d: stream %d, no descriptor found\n", source_track->track_id, st->index);
781
            continue;
782
        }
783
        PRINT_KEY(mxf->fc, "essence codec     ul", descriptor->essence_codec_ul);
784
        PRINT_KEY(mxf->fc, "essence container ul", descriptor->essence_container_ul);
785
        essence_container_ul = &descriptor->essence_container_ul;
786
        /* HACK: replacing the original key with mxf_encrypted_essence_container
787
         * is not allowed according to s429-6, try to find correct information anyway */
788
        if (IS_KLV_KEY(essence_container_ul, mxf_encrypted_essence_container)) {
789
            av_log(mxf->fc, AV_LOG_INFO, "broken encrypted mxf file\n");
790
            for (k = 0; k < mxf->metadata_sets_count; k++) {
791
                MXFMetadataSet *metadata = mxf->metadata_sets[k];
792
                if (metadata->type == CryptoContext) {
793
                    essence_container_ul = &((MXFCryptoContext *)metadata)->source_container_ul;
794
                    break;
795
                }
796
            }
797
        }
798
        /* TODO: drop PictureEssenceCoding and SoundEssenceCompression, only check EssenceContainer */
799
        codec_ul = mxf_get_codec_ul(ff_mxf_codec_uls, &descriptor->essence_codec_ul);
800
        st->codec->codec_id = codec_ul->id;
801
        if (descriptor->extradata) {
802
            st->codec->extradata = descriptor->extradata;
803
            st->codec->extradata_size = descriptor->extradata_size;
804
        }
805
        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
806
            container_ul = mxf_get_codec_ul(mxf_essence_container_uls, essence_container_ul);
807
            if (st->codec->codec_id == CODEC_ID_NONE)
808
                st->codec->codec_id = container_ul->id;
809
            st->codec->width = descriptor->width;
810
            st->codec->height = descriptor->height;
811
            if (st->codec->codec_id == CODEC_ID_RAWVIDEO)
812
                st->codec->pix_fmt = descriptor->pix_fmt;
813
            st->need_parsing = AVSTREAM_PARSE_HEADERS;
814
        } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
815
            container_ul = mxf_get_codec_ul(mxf_essence_container_uls, essence_container_ul);
816
            if (st->codec->codec_id == CODEC_ID_NONE)
817
                st->codec->codec_id = container_ul->id;
818
            st->codec->channels = descriptor->channels;
819
            st->codec->bits_per_coded_sample = descriptor->bits_per_sample;
820
            st->codec->sample_rate = descriptor->sample_rate.num / descriptor->sample_rate.den;
821
            /* TODO: implement CODEC_ID_RAWAUDIO */
822
            if (st->codec->codec_id == CODEC_ID_PCM_S16LE) {
823
                if (descriptor->bits_per_sample == 24)
824
                    st->codec->codec_id = CODEC_ID_PCM_S24LE;
825
                else if (descriptor->bits_per_sample == 32)
826
                    st->codec->codec_id = CODEC_ID_PCM_S32LE;
827
            } else if (st->codec->codec_id == CODEC_ID_PCM_S16BE) {
828
                if (descriptor->bits_per_sample == 24)
829
                    st->codec->codec_id = CODEC_ID_PCM_S24BE;
830
                else if (descriptor->bits_per_sample == 32)
831
                    st->codec->codec_id = CODEC_ID_PCM_S32BE;
832
            } else if (st->codec->codec_id == CODEC_ID_MP2) {
833
                st->need_parsing = AVSTREAM_PARSE_FULL;
834
            }
835
        }
836
        if (st->codec->codec_type != AVMEDIA_TYPE_DATA && (*essence_container_ul)[15] > 0x01) {
837
            av_log(mxf->fc, AV_LOG_WARNING, "only frame wrapped mappings are correctly supported\n");
838
            st->need_parsing = AVSTREAM_PARSE_FULL;
839
        }
840
    }
841
    return 0;
842
}
843

    
844
static const MXFMetadataReadTableEntry mxf_metadata_read_table[] = {
845
    { { 0x06,0x0E,0x2B,0x34,0x02,0x05,0x01,0x01,0x0d,0x01,0x02,0x01,0x01,0x05,0x01,0x00 }, mxf_read_primer_pack },
846
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x18,0x00 }, mxf_read_content_storage, 0, AnyType },
847
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x37,0x00 }, mxf_read_source_package, sizeof(MXFPackage), SourcePackage },
848
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x36,0x00 }, mxf_read_material_package, sizeof(MXFPackage), MaterialPackage },
849
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x0F,0x00 }, mxf_read_sequence, sizeof(MXFSequence), Sequence },
850
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x11,0x00 }, mxf_read_source_clip, sizeof(MXFStructuralComponent), SourceClip },
851
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x44,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), MultipleDescriptor },
852
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x42,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* Generic Sound */
853
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x28,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* CDCI */
854
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x29,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* RGBA */
855
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x51,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* MPEG 2 Video */
856
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x48,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* Wave */
857
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x47,0x00 }, mxf_read_generic_descriptor, sizeof(MXFDescriptor), Descriptor }, /* AES3 */
858
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x3A,0x00 }, mxf_read_track, sizeof(MXFTrack), Track }, /* Static Track */
859
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x01,0x01,0x01,0x01,0x3B,0x00 }, mxf_read_track, sizeof(MXFTrack), Track }, /* Generic Track */
860
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x04,0x01,0x02,0x02,0x00,0x00 }, mxf_read_cryptographic_context, sizeof(MXFCryptoContext), CryptoContext },
861
    { { 0x06,0x0E,0x2B,0x34,0x02,0x53,0x01,0x01,0x0d,0x01,0x02,0x01,0x01,0x10,0x01,0x00 }, mxf_read_index_table_segment, sizeof(MXFIndexTableSegment), IndexTableSegment },
862
    { { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, NULL, 0, AnyType },
863
};
864

    
865
static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadFunc *read_child, int ctx_size, enum MXFMetadataSetType type)
866
{
867
    AVIOContext *pb = mxf->fc->pb;
868
    MXFMetadataSet *ctx = ctx_size ? av_mallocz(ctx_size) : mxf;
869
    uint64_t klv_end = url_ftell(pb) + klv->length;
870

    
871
    if (!ctx)
872
        return -1;
873
    while (url_ftell(pb) + 4 < klv_end) {
874
        int tag = avio_rb16(pb);
875
        int size = avio_rb16(pb); /* KLV specified by 0x53 */
876
        uint64_t next = url_ftell(pb) + size;
877
        UID uid = {0};
878

    
879
        av_dlog(mxf->fc, "local tag %#04x size %d\n", tag, size);
880
        if (!size) { /* ignore empty tag, needed for some files with empty UMID tag */
881
            av_log(mxf->fc, AV_LOG_ERROR, "local tag %#04x with 0 size\n", tag);
882
            continue;
883
        }
884
        if (tag > 0x7FFF) { /* dynamic tag */
885
            int i;
886
            for (i = 0; i < mxf->local_tags_count; i++) {
887
                int local_tag = AV_RB16(mxf->local_tags+i*18);
888
                if (local_tag == tag) {
889
                    memcpy(uid, mxf->local_tags+i*18+2, 16);
890
                    av_dlog(mxf->fc, "local tag %#04x\n", local_tag);
891
                    PRINT_KEY(mxf->fc, "uid", uid);
892
                }
893
            }
894
        }
895
        if (ctx_size && tag == 0x3C0A)
896
            avio_read(pb, ctx->uid, 16);
897
        else if (read_child(ctx, pb, tag, size, uid) < 0)
898
            return -1;
899

    
900
        url_fseek(pb, next, SEEK_SET);
901
    }
902
    if (ctx_size) ctx->type = type;
903
    return ctx_size ? mxf_add_metadata_set(mxf, ctx) : 0;
904
}
905

    
906
static int mxf_read_header(AVFormatContext *s, AVFormatParameters *ap)
907
{
908
    MXFContext *mxf = s->priv_data;
909
    KLVPacket klv;
910

    
911
    if (!mxf_read_sync(s->pb, mxf_header_partition_pack_key, 14)) {
912
        av_log(s, AV_LOG_ERROR, "could not find header partition pack key\n");
913
        return -1;
914
    }
915
    url_fseek(s->pb, -14, SEEK_CUR);
916
    mxf->fc = s;
917
    while (!url_feof(s->pb)) {
918
        const MXFMetadataReadTableEntry *metadata;
919

    
920
        if (klv_read_packet(&klv, s->pb) < 0)
921
            return -1;
922
        PRINT_KEY(s, "read header", klv.key);
923
        av_dlog(s, "size %lld offset %#llx\n", klv.length, klv.offset);
924
        if (IS_KLV_KEY(klv.key, mxf_encrypted_triplet_key) ||
925
            IS_KLV_KEY(klv.key, mxf_essence_element_key)) {
926
            /* FIXME avoid seek */
927
            url_fseek(s->pb, klv.offset, SEEK_SET);
928
            break;
929
        }
930

    
931
        for (metadata = mxf_metadata_read_table; metadata->read; metadata++) {
932
            if (IS_KLV_KEY(klv.key, metadata->key)) {
933
                int res;
934
                if (klv.key[5] == 0x53) {
935
                    res = mxf_read_local_tags(mxf, &klv, metadata->read, metadata->ctx_size, metadata->type);
936
                } else
937
                    res = metadata->read(mxf, s->pb, 0, 0, NULL);
938
                if (res < 0) {
939
                    av_log(s, AV_LOG_ERROR, "error reading header metadata\n");
940
                    return -1;
941
                }
942
                break;
943
            }
944
        }
945
        if (!metadata->read)
946
            url_fskip(s->pb, klv.length);
947
    }
948
    return mxf_parse_structural_metadata(mxf);
949
}
950

    
951
static int mxf_read_close(AVFormatContext *s)
952
{
953
    MXFContext *mxf = s->priv_data;
954
    int i;
955

    
956
    av_freep(&mxf->packages_refs);
957

    
958
    for (i = 0; i < s->nb_streams; i++)
959
        s->streams[i]->priv_data = NULL;
960

    
961
    for (i = 0; i < mxf->metadata_sets_count; i++) {
962
        switch (mxf->metadata_sets[i]->type) {
963
        case MultipleDescriptor:
964
            av_freep(&((MXFDescriptor *)mxf->metadata_sets[i])->sub_descriptors_refs);
965
            break;
966
        case Sequence:
967
            av_freep(&((MXFSequence *)mxf->metadata_sets[i])->structural_components_refs);
968
            break;
969
        case SourcePackage:
970
        case MaterialPackage:
971
            av_freep(&((MXFPackage *)mxf->metadata_sets[i])->tracks_refs);
972
            break;
973
        default:
974
            break;
975
        }
976
        av_freep(&mxf->metadata_sets[i]);
977
    }
978
    av_freep(&mxf->metadata_sets);
979
    av_freep(&mxf->aesc);
980
    av_freep(&mxf->local_tags);
981
    return 0;
982
}
983

    
984
static int mxf_probe(AVProbeData *p) {
985
    uint8_t *bufp = p->buf;
986
    uint8_t *end = p->buf + p->buf_size;
987

    
988
    if (p->buf_size < sizeof(mxf_header_partition_pack_key))
989
        return 0;
990

    
991
    /* Must skip Run-In Sequence and search for MXF header partition pack key SMPTE 377M 5.5 */
992
    end -= sizeof(mxf_header_partition_pack_key);
993
    for (; bufp < end; bufp++) {
994
        if (IS_KLV_KEY(bufp, mxf_header_partition_pack_key))
995
            return AVPROBE_SCORE_MAX;
996
    }
997
    return 0;
998
}
999

    
1000
/* rudimentary byte seek */
1001
/* XXX: use MXF Index */
1002
static int mxf_read_seek(AVFormatContext *s, int stream_index, int64_t sample_time, int flags)
1003
{
1004
    AVStream *st = s->streams[stream_index];
1005
    int64_t seconds;
1006

    
1007
    if (!s->bit_rate)
1008
        return -1;
1009
    if (sample_time < 0)
1010
        sample_time = 0;
1011
    seconds = av_rescale(sample_time, st->time_base.num, st->time_base.den);
1012
    url_fseek(s->pb, (s->bit_rate * seconds) >> 3, SEEK_SET);
1013
    av_update_cur_dts(s, st, sample_time);
1014
    return 0;
1015
}
1016

    
1017
AVInputFormat ff_mxf_demuxer = {
1018
    "mxf",
1019
    NULL_IF_CONFIG_SMALL("Material eXchange Format"),
1020
    sizeof(MXFContext),
1021
    mxf_probe,
1022
    mxf_read_header,
1023
    mxf_read_packet,
1024
    mxf_read_close,
1025
    mxf_read_seek,
1026
};