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1
/*
2
 * GXF demuxer.
3
 * Copyright (c) 2006 Reimar Doeffinger.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
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 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
 */
19
#include "avformat.h"
20
#include "common.h"
21

    
22
typedef enum {
23
    PKT_MAP = 0xbc,
24
    PKT_MEDIA = 0xbf,
25
    PKT_EOS = 0xfb,
26
    PKT_FLT = 0xfc,
27
    PKT_UMF = 0xfd
28
} pkt_type_t;
29

    
30
typedef enum {
31
    MAT_NAME = 0x40,
32
    MAT_FIRST_FIELD = 0x41,
33
    MAT_LAST_FIELD = 0x42,
34
    MAT_MARK_IN = 0x43,
35
    MAT_MARK_OUT = 0x44,
36
    MAT_SIZE = 0x45
37
} mat_tag_t;
38

    
39
typedef enum {
40
    TRACK_NAME = 0x4c,
41
    TRACK_AUX = 0x4d,
42
    TRACK_VER = 0x4e,
43
    TRACK_MPG_AUX = 0x4f,
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    TRACK_FPS = 0x50,
45
    TRACK_LINES = 0x51,
46
    TRACK_FPF = 0x52
47
} track_tag_t;
48

    
49
typedef struct {
50
    int64_t first_field;
51
    int64_t last_field;
52
    AVRational frames_per_second;
53
    int32_t fields_per_frame;
54
} st_info_t;
55

    
56
/**
57
 * \brief parses a packet header, extracting type and length
58
 * \param pb ByteIOContext to read header from
59
 * \param type detected packet type is stored here
60
 * \param length detected packet length, excluding header is stored here
61
 * \return 0 if header not found or contains invalid data, 1 otherwise
62
 */
63
static int parse_packet_header(ByteIOContext *pb, pkt_type_t *type, int *length) {
64
    if (get_be32(pb))
65
        return 0;
66
    if (get_byte(pb) != 1)
67
        return 0;
68
    *type = get_byte(pb);
69
    *length = get_be32(pb);
70
    if ((*length >> 24) || *length < 16)
71
        return 0;
72
    *length -= 16;
73
    if (get_be32(pb))
74
        return 0;
75
    if (get_byte(pb) != 0xe1)
76
        return 0;
77
    if (get_byte(pb) != 0xe2)
78
        return 0;
79
    return 1;
80
}
81

    
82
/**
83
 * \brief check if file starts with a PKT_MAP header
84
 */
85
static int gxf_probe(AVProbeData *p) {
86
    static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
87
    static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
88
    if (p->buf_size < 16)
89
        return 0;
90
    if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
91
        !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
92
        return AVPROBE_SCORE_MAX;
93
    return 0;
94
}
95

    
96
/**
97
 * \brief gets the stream index for the track with the specified id, creates new
98
 *        stream if not found
99
 * \param stream id of stream to find / add
100
 * \param format stream format identifier
101
 */
102
static int get_sindex(AVFormatContext *s, int id, int format) {
103
    int i;
104
    AVStream *st = NULL;
105
    for (i = 0; i < s->nb_streams; i++) {
106
        if (s->streams[i]->id == id)
107
            return i;
108
    }
109
    st = av_new_stream(s, id);
110
    switch (format) {
111
        case 3:
112
        case 4:
113
            st->codec->codec_type = CODEC_TYPE_VIDEO;
114
            st->codec->codec_id = CODEC_ID_MJPEG;
115
            break;
116
        case 13:
117
        case 15:
118
            st->codec->codec_type = CODEC_TYPE_VIDEO;
119
            st->codec->codec_id = CODEC_ID_DVVIDEO;
120
            break;
121
        case 14:
122
        case 16:
123
            st->codec->codec_type = CODEC_TYPE_VIDEO;
124
            st->codec->codec_id = CODEC_ID_DVVIDEO;
125
            break;
126
        case 11:
127
        case 12:
128
        case 20:
129
            st->codec->codec_type = CODEC_TYPE_VIDEO;
130
            st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
131
            break;
132
        case 22:
133
        case 23:
134
            st->codec->codec_type = CODEC_TYPE_VIDEO;
135
            st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
136
            break;
137
        case 9:
138
            st->codec->codec_type = CODEC_TYPE_AUDIO;
139
            st->codec->codec_id = CODEC_ID_PCM_S24LE;
140
            st->codec->channels = 1;
141
            st->codec->sample_rate = 48000;
142
            st->codec->bit_rate = 3 * 1 * 48000 * 8;
143
            st->codec->block_align = 3 * 1;
144
            st->codec->bits_per_sample = 24;
145
            break;
146
        case 10:
147
            st->codec->codec_type = CODEC_TYPE_AUDIO;
148
            st->codec->codec_id = CODEC_ID_PCM_S16LE;
149
            st->codec->channels = 1;
150
            st->codec->sample_rate = 48000;
151
            st->codec->bit_rate = 2 * 1 * 48000 * 8;
152
            st->codec->block_align = 2 * 1;
153
            st->codec->bits_per_sample = 16;
154
            break;
155
        case 17:
156
            st->codec->codec_type = CODEC_TYPE_AUDIO;
157
            st->codec->codec_id = CODEC_ID_AC3;
158
            st->codec->channels = 2;
159
            st->codec->sample_rate = 48000;
160
            break;
161
        default:
162
            st->codec->codec_type = CODEC_TYPE_UNKNOWN;
163
            st->codec->codec_id = CODEC_ID_NONE;
164
            break;
165
    }
166
    return s->nb_streams - 1;
167
}
168

    
169
/**
170
 * \brief filters out interesting tags from material information.
171
 * \param len lenght of tag section, will be adjusted to contain remaining bytes
172
 * \param si struct to store collected information into
173
 */
174
static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
175
    si->first_field = AV_NOPTS_VALUE;
176
    si->last_field = AV_NOPTS_VALUE;
177
    while (*len >= 2) {
178
        mat_tag_t tag = get_byte(pb);
179
        int tlen = get_byte(pb);
180
        *len -= 2;
181
        if (tlen > *len)
182
            return;
183
        *len -= tlen;
184
        if (tlen == 4) {
185
            uint32_t value = get_be32(pb);
186
            if (tag == MAT_FIRST_FIELD)
187
                si->first_field = value;
188
            else if (tag == MAT_LAST_FIELD)
189
                si->last_field = value;
190
        } else
191
            url_fskip(pb, tlen);
192
    }
193
}
194

    
195
/**
196
 * \brief convert fps tag value to AVRational fps
197
 * \param fps fps value from tag
198
 * \return fps as AVRational, or 0 / 0 if unknown
199
 */
200
static AVRational fps_tag2avr(int32_t fps) {
201
    extern const AVRational ff_frame_rate_tab[];
202
    if (fps < 1 || fps > 9) fps = 9;
203
    return ff_frame_rate_tab[9 - fps]; // values have opposite order
204
}
205

    
206
/**
207
 * \brief convert UMF attributes flags to AVRational fps
208
 * \param fps fps value from flags
209
 * \return fps as AVRational, or 0 / 0 if unknown
210
 */
211
static AVRational fps_umf2avr(uint32_t flags) {
212
    static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
213
        {25, 1}, {30000, 1001}};
214
    int idx =  av_log2((flags & 0x7c0) >> 6);
215
    return map[idx];
216
}
217

    
218
/**
219
 * \brief filters out interesting tags from track information.
220
 * \param len length of tag section, will be adjusted to contain remaining bytes
221
 * \param si struct to store collected information into
222
 */
223
static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
224
    si->frames_per_second = (AVRational){0, 0};
225
    si->fields_per_frame = 0;
226
    while (*len >= 2) {
227
        track_tag_t tag = get_byte(pb);
228
        int tlen = get_byte(pb);
229
        *len -= 2;
230
        if (tlen > *len)
231
            return;
232
        *len -= tlen;
233
        if (tlen == 4) {
234
            uint32_t value = get_be32(pb);
235
            if (tag == TRACK_FPS)
236
                si->frames_per_second = fps_tag2avr(value);
237
            else if (tag == TRACK_FPF && (value == 1 || value == 2))
238
                si->fields_per_frame = value;
239
        } else
240
            url_fskip(pb, tlen);
241
    }
242
}
243

    
244
/**
245
 * \brief read index from FLT packet into stream 0 av_index
246
 */
247
static void gxf_read_index(AVFormatContext *s, int pkt_len) {
248
    ByteIOContext *pb = &s->pb;
249
    AVStream *st = s->streams[0];
250
    uint32_t fields_per_map = get_le32(pb);
251
    uint32_t map_cnt = get_le32(pb);
252
    int i;
253
    pkt_len -= 8;
254
    if (map_cnt > 1000) {
255
        av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
256
        map_cnt = 1000;
257
    }
258
    if (pkt_len < 4 * map_cnt) {
259
        av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
260
        url_fskip(pb, pkt_len);
261
        return;
262
    }
263
    pkt_len -= 4 * map_cnt;
264
    av_add_index_entry(st, 0, 0, 0, 0, 0);
265
    for (i = 0; i < map_cnt; i++)
266
        av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
267
                           i * (uint64_t)fields_per_map + 1, 0, 0, 0);
268
    url_fskip(pb, pkt_len);
269
}
270

    
271
static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
272
    ByteIOContext *pb = &s->pb;
273
    pkt_type_t pkt_type;
274
    int map_len;
275
    int len;
276
    AVRational main_timebase = {0, 0};
277
    st_info_t si;
278
    int i;
279
    if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
280
        av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
281
        return 0;
282
    }
283
    map_len -= 2;
284
    if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
285
        av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
286
        return 0;
287
    }
288
    map_len -= 2;
289
    len = get_be16(pb); // length of material data section
290
    if (len > map_len) {
291
        av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
292
        return 0;
293
    }
294
    map_len -= len;
295
    gxf_material_tags(pb, &len, &si);
296
    url_fskip(pb, len);
297
    map_len -= 2;
298
    len = get_be16(pb); // length of track description
299
    if (len > map_len) {
300
        av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
301
        return 0;
302
    }
303
    map_len -= len;
304
    while (len > 0) {
305
        int track_type, track_id, track_len;
306
        AVStream *st;
307
        int idx;
308
        len -= 4;
309
        track_type = get_byte(pb);
310
        track_id = get_byte(pb);
311
        track_len = get_be16(pb);
312
        len -= track_len;
313
        gxf_track_tags(pb, &track_len, &si);
314
        url_fskip(pb, track_len);
315
        if (!(track_type & 0x80)) {
316
           av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
317
           continue;
318
        }
319
        track_type &= 0x7f;
320
        if ((track_id & 0xc0) != 0xc0) {
321
           av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
322
           continue;
323
        }
324
        track_id &= 0x3f;
325
        idx = get_sindex(s, track_id, track_type);
326
        if (idx < 0) continue;
327
        st = s->streams[idx];
328
        if (!main_timebase.num || !main_timebase.den) {
329
            main_timebase.num = si.frames_per_second.den;
330
            main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
331
        }
332
        st->start_time = si.first_field;
333
        if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
334
            st->duration = si.last_field - si.first_field;
335
    }
336
    if (len < 0)
337
        av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
338
    if (map_len)
339
        url_fskip(pb, map_len);
340
    if (!parse_packet_header(pb, &pkt_type, &len)) {
341
        av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
342
        return -1;
343
    }
344
    if (pkt_type == PKT_FLT) {
345
        gxf_read_index(s, len);
346
        if (!parse_packet_header(pb, &pkt_type, &len)) {
347
            av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
348
            return -1;
349
        }
350
    }
351
    if (pkt_type == PKT_UMF) {
352
        if (len >= 9) {
353
            AVRational fps;
354
            len -= 9;
355
            url_fskip(pb, 5);
356
            fps = fps_umf2avr(get_le32(pb));
357
            if (!main_timebase.num || !main_timebase.den) {
358
                // this may not always be correct, but simply the best we can get
359
                main_timebase.num = fps.den;
360
                main_timebase.den = fps.num;
361
            }
362
        } else
363
            av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
364
    } else
365
        av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
366
    url_fskip(pb, len);
367
    for (i = 0; i < s->nb_streams; i++) {
368
        AVStream *st = s->streams[i];
369
        if (main_timebase.num && main_timebase.den)
370
            st->time_base = main_timebase;
371
        else {
372
            st->start_time = st->duration = AV_NOPTS_VALUE;
373
        }
374
    }
375
    return 0;
376
}
377

    
378
#define READ_ONE() \
379
    { \
380
        if (!max_interval-- || url_feof(pb)) \
381
            goto out; \
382
        tmp = tmp << 8 | get_byte(pb); \
383
    }
384

    
385
/**
386
 * \brief resync the stream on the next media packet with specified properties
387
 * \param max_interval how many bytes to search for matching packet at most
388
 * \param track track id the media packet must belong to, -1 for any
389
 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
390
 * \return timestamp of packet found
391
 */
392
static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
393
    uint32_t tmp;
394
    uint64_t last_pos;
395
    uint64_t last_found_pos = 0;
396
    int cur_track;
397
    int64_t cur_timestamp = AV_NOPTS_VALUE;
398
    int len;
399
    ByteIOContext *pb = &s->pb;
400
    pkt_type_t type;
401
    tmp = get_be32(pb);
402
start:
403
    while (tmp)
404
        READ_ONE();
405
    READ_ONE();
406
    if (tmp != 1)
407
        goto start;
408
    last_pos = url_ftell(pb);
409
    url_fseek(pb, -5, SEEK_CUR);
410
    if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
411
        url_fseek(pb, last_pos, SEEK_SET);
412
        goto start;
413
    }
414
    get_byte(pb);
415
    cur_track = get_byte(pb);
416
    cur_timestamp = get_be32(pb);
417
    last_found_pos = url_ftell(pb) - 16 - 6;
418
    if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
419
        url_fseek(pb, last_pos, SEEK_SET);
420
        goto start;
421
    }
422
out:
423
    if (last_found_pos)
424
        url_fseek(pb, last_found_pos, SEEK_SET);
425
    return cur_timestamp;
426
}
427

    
428
static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
429
    ByteIOContext *pb = &s->pb;
430
    pkt_type_t pkt_type;
431
    int pkt_len;
432
    while (!url_feof(pb)) {
433
        int track_type, track_id, ret;
434
        int field_nr;
435
        if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
436
            if (!url_feof(pb))
437
                av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
438
            return -1;
439
        }
440
        if (pkt_type == PKT_FLT) {
441
            gxf_read_index(s, pkt_len);
442
            continue;
443
        }
444
        if (pkt_type != PKT_MEDIA) {
445
            url_fskip(pb, pkt_len);
446
            continue;
447
        }
448
        if (pkt_len < 16) {
449
            av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
450
            continue;
451
        }
452
        pkt_len -= 16;
453
        track_type = get_byte(pb);
454
        track_id = get_byte(pb);
455
        field_nr = get_be32(pb);
456
        get_be32(pb); // field information
457
        get_be32(pb); // "timeline" field number
458
        get_byte(pb); // flags
459
        get_byte(pb); // reserved
460
        // NOTE: there is also data length information in the
461
        // field information, it might be better to take this into account
462
        // as well.
463
        ret = av_get_packet(pb, pkt, pkt_len);
464
        pkt->stream_index = get_sindex(s, track_id, track_type);
465
        pkt->pts = field_nr;
466
        return ret;
467
    }
468
    return AVERROR_IO;
469
}
470

    
471
static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
472
    uint64_t pos;
473
    uint64_t maxlen = 100 * 1024 * 1024;
474
    AVStream *st = s->streams[0];
475
    int64_t start_time = s->streams[stream_index]->start_time;
476
    int64_t found;
477
    int idx;
478
    if (timestamp < start_time) timestamp = start_time;
479
    idx = av_index_search_timestamp(st, timestamp - start_time,
480
                                    AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
481
    if (idx < 0)
482
        return -1;
483
    pos = st->index_entries[idx].pos;
484
    if (idx < st->nb_index_entries - 2)
485
        maxlen = st->index_entries[idx + 2].pos - pos;
486
    maxlen = FFMAX(maxlen, 200 * 1024);
487
    url_fseek(&s->pb, pos, SEEK_SET);
488
    found = gxf_resync_media(s, maxlen, -1, timestamp);
489
    if (ABS(found - timestamp) > 4)
490
        return -1;
491
    return 0;
492
}
493

    
494
static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
495
                                  int64_t *pos, int64_t pos_limit) {
496
    ByteIOContext *pb = &s->pb;
497
    int64_t res;
498
    url_fseek(pb, *pos, SEEK_SET);
499
    res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
500
    *pos = url_ftell(pb);
501
    return res;
502
}
503

    
504
AVInputFormat gxf_demuxer = {
505
    "gxf",
506
    "GXF format",
507
    0,
508
    gxf_probe,
509
    gxf_header,
510
    gxf_packet,
511
    NULL,
512
    gxf_seek,
513
    gxf_read_timestamp,
514
};