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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
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library 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
13
 * 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 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 {
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    PKT_MAP = 0xbc,
24
    PKT_MEDIA = 0xbf,
25
    PKT_EOS = 0xfb,
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    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,
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    MAT_MARK_OUT = 0x44,
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    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,
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    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->codec_tag = 0x1;
141
            st->codec->channels = 1;
142
            st->codec->sample_rate = 48000;
143
            st->codec->bit_rate = 3 * 1 * 48000 * 8;
144
            st->codec->block_align = 3 * 1;
145
            st->codec->bits_per_sample = 24;
146
            break;
147
        case 10:
148
            st->codec->codec_type = CODEC_TYPE_AUDIO;
149
            st->codec->codec_id = CODEC_ID_PCM_S16LE;
150
            st->codec->codec_tag = 0x1;
151
            st->codec->channels = 1;
152
            st->codec->sample_rate = 48000;
153
            st->codec->bit_rate = 2 * 1 * 48000 * 8;
154
            st->codec->block_align = 2 * 1;
155
            st->codec->bits_per_sample = 16;
156
            break;
157
        case 17:
158
            st->codec->codec_type = CODEC_TYPE_AUDIO;
159
            st->codec->codec_id = CODEC_ID_AC3;
160
            st->codec->codec_tag = 0x2000;
161
            st->codec->channels = 2;
162
            st->codec->sample_rate = 48000;
163
            break;
164
        default:
165
            st->codec->codec_type = CODEC_TYPE_UNKNOWN;
166
            st->codec->codec_id = CODEC_ID_NONE;
167
            break;
168
    }
169
    return s->nb_streams - 1;
170
}
171

    
172
/**
173
 * \brief filters out interesting tags from material information.
174
 * \param len lenght of tag section, will be adjusted to contain remaining bytes
175
 * \param si struct to store collected information into
176
 */
177
static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
178
    si->first_field = AV_NOPTS_VALUE;
179
    si->last_field = AV_NOPTS_VALUE;
180
    while (*len >= 2) {
181
        mat_tag_t tag = get_byte(pb);
182
        int tlen = get_byte(pb);
183
        *len -= 2;
184
        if (tlen > *len)
185
            return;
186
        *len -= tlen;
187
        if (tlen == 4) {
188
            uint32_t value = get_be32(pb);
189
            if (tag == MAT_FIRST_FIELD)
190
                si->first_field = value;
191
            else if (tag == MAT_LAST_FIELD)
192
                si->last_field = value;
193
        } else
194
            url_fskip(pb, tlen);
195
    }
196
}
197

    
198
/**
199
 * \brief convert fps tag value to AVRational fps
200
 * \param fps fps value from tag
201
 * \return fps as AVRational, or 0 / 0 if unknown
202
 */
203
static AVRational fps_tag2avr(int32_t fps) {
204
    extern const AVRational ff_frame_rate_tab[];
205
    if (fps < 1 || fps > 9) fps = 9;
206
    return ff_frame_rate_tab[9 - fps]; // values have opposite order
207
}
208

    
209
/**
210
 * \brief convert UMF attributes flags to AVRational fps
211
 * \param fps fps value from flags
212
 * \return fps as AVRational, or 0 / 0 if unknown
213
 */
214
static AVRational fps_umf2avr(uint32_t flags) {
215
    static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
216
        {25, 1}, {30000, 1001}};
217
    int idx =  av_log2((flags & 0x7c0) >> 6);
218
    return map[idx];
219
}
220

    
221
/**
222
 * \brief filters out interesting tags from track information.
223
 * \param len length of tag section, will be adjusted to contain remaining bytes
224
 * \param si struct to store collected information into
225
 */
226
static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
227
    si->frames_per_second = (AVRational){0, 0};
228
    si->fields_per_frame = 0;
229
    while (*len >= 2) {
230
        track_tag_t tag = get_byte(pb);
231
        int tlen = get_byte(pb);
232
        *len -= 2;
233
        if (tlen > *len)
234
            return;
235
        *len -= tlen;
236
        if (tlen == 4) {
237
            uint32_t value = get_be32(pb);
238
            if (tag == TRACK_FPS)
239
                si->frames_per_second = fps_tag2avr(value);
240
            else if (tag == TRACK_FPF && (value == 1 || value == 2))
241
                si->fields_per_frame = value;
242
        } else
243
            url_fskip(pb, tlen);
244
    }
245
}
246

    
247
/**
248
 * \brief read index from FLT packet into stream 0 av_index
249
 */
250
static void gxf_read_index(AVFormatContext *s, int pkt_len) {
251
    ByteIOContext *pb = &s->pb;
252
    AVStream *st = s->streams[0];
253
    uint32_t fields_per_map = get_le32(pb);
254
    uint32_t map_cnt = get_le32(pb);
255
    int i;
256
    pkt_len -= 8;
257
    if (map_cnt > 1000) {
258
        av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
259
        map_cnt = 1000;
260
    }
261
    if (pkt_len < 4 * map_cnt) {
262
        av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
263
        url_fskip(pb, pkt_len);
264
        return;
265
    }
266
    pkt_len -= 4 * map_cnt;
267
    av_add_index_entry(st, 0, 0, 0, 0, 0);
268
    for (i = 0; i < map_cnt; i++)
269
        av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
270
                           i * (uint64_t)fields_per_map + 1, 0, 0, 0);
271
    url_fskip(pb, pkt_len);
272
}
273

    
274
static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
275
    ByteIOContext *pb = &s->pb;
276
    pkt_type_t pkt_type;
277
    int map_len;
278
    int len;
279
    AVRational main_timebase = {0, 0};
280
    st_info_t si;
281
    int i;
282
    if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
283
        av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
284
        return 0;
285
    }
286
    map_len -= 2;
287
    if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
288
        av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
289
        return 0;
290
    }
291
    map_len -= 2;
292
    len = get_be16(pb); // length of material data section
293
    if (len > map_len) {
294
        av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
295
        return 0;
296
    }
297
    map_len -= len;
298
    gxf_material_tags(pb, &len, &si);
299
    url_fskip(pb, len);
300
    map_len -= 2;
301
    len = get_be16(pb); // length of track description
302
    if (len > map_len) {
303
        av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
304
        return 0;
305
    }
306
    map_len -= len;
307
    while (len > 0) {
308
        int track_type, track_id, track_len;
309
        AVStream *st;
310
        int idx;
311
        len -= 4;
312
        track_type = get_byte(pb);
313
        track_id = get_byte(pb);
314
        track_len = get_be16(pb);
315
        len -= track_len;
316
        gxf_track_tags(pb, &track_len, &si);
317
        url_fskip(pb, track_len);
318
        if (!(track_type & 0x80)) {
319
           av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
320
           continue;
321
        }
322
        track_type &= 0x7f;
323
        if ((track_id & 0xc0) != 0xc0) {
324
           av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
325
           continue;
326
        }
327
        track_id &= 0x3f;
328
        idx = get_sindex(s, track_id, track_type);
329
        if (idx < 0) continue;
330
        st = s->streams[idx];
331
        if (!main_timebase.num || !main_timebase.den) {
332
            main_timebase.num = si.frames_per_second.den;
333
            main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
334
        }
335
        st->start_time = si.first_field;
336
        if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
337
            st->duration = si.last_field - si.first_field;
338
    }
339
    if (len < 0)
340
        av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
341
    if (map_len)
342
        url_fskip(pb, map_len);
343
    if (!parse_packet_header(pb, &pkt_type, &len)) {
344
        av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
345
        return -1;
346
    }
347
    if (pkt_type == PKT_FLT) {
348
        gxf_read_index(s, len);
349
        if (!parse_packet_header(pb, &pkt_type, &len)) {
350
            av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
351
            return -1;
352
        }
353
    }
354
    if (pkt_type == PKT_UMF) {
355
        if (len >= 9) {
356
            AVRational fps;
357
            len -= 9;
358
            url_fskip(pb, 5);
359
            fps = fps_umf2avr(get_le32(pb));
360
            if (!main_timebase.num || !main_timebase.den) {
361
                // this may not always be correct, but simply the best we can get
362
                main_timebase.num = fps.den;
363
                main_timebase.den = fps.num;
364
            }
365
        } else
366
            av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
367
    } else
368
        av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
369
    url_fskip(pb, len);
370
    for (i = 0; i < s->nb_streams; i++) {
371
        AVStream *st = s->streams[i];
372
        if (main_timebase.num && main_timebase.den)
373
            st->time_base = main_timebase;
374
        else {
375
            st->start_time = st->duration = AV_NOPTS_VALUE;
376
        }
377
    }
378
    return 0;
379
}
380

    
381
#define READ_ONE() \
382
    { \
383
        if (!max_interval-- || url_feof(pb)) \
384
            goto out; \
385
        tmp = tmp << 8 | get_byte(pb); \
386
    }
387

    
388
/**
389
 * \brief resync the stream on the next media packet with specified properties
390
 * \param max_interval how many bytes to search for matching packet at most
391
 * \param track track id the media packet must belong to, -1 for any
392
 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
393
 * \return timestamp of packet found
394
 */
395
static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
396
    uint32_t tmp;
397
    uint64_t last_pos;
398
    uint64_t last_found_pos = 0;
399
    int cur_track;
400
    int64_t cur_timestamp = AV_NOPTS_VALUE;
401
    int len;
402
    ByteIOContext *pb = &s->pb;
403
    pkt_type_t type;
404
    tmp = 0xff;
405
start:
406
    while (tmp)
407
        READ_ONE();
408
    READ_ONE();
409
    if (tmp != 1)
410
        goto start;
411
    last_pos = url_ftell(pb);
412
    url_fseek(pb, -5, SEEK_CUR);
413
    if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
414
        url_fseek(pb, last_pos, SEEK_SET);
415
        goto start;
416
    }
417
    get_byte(pb);
418
    cur_track = get_byte(pb);
419
    cur_timestamp = get_be32(pb);
420
    last_found_pos = url_ftell(pb) - 16 - 6;
421
    if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
422
        url_fseek(pb, last_pos, SEEK_SET);
423
        goto start;
424
    }
425
out:
426
    if (last_found_pos)
427
        url_fseek(pb, last_found_pos, SEEK_SET);
428
    return cur_timestamp;
429
}
430

    
431
static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
432
    ByteIOContext *pb = &s->pb;
433
    pkt_type_t pkt_type;
434
    int pkt_len;
435
    while (!url_feof(pb)) {
436
        int track_type, track_id, ret;
437
        int field_nr;
438
        if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
439
            if (!url_feof(pb))
440
                av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
441
            return -1;
442
        }
443
        if (pkt_type == PKT_FLT) {
444
            gxf_read_index(s, pkt_len);
445
            continue;
446
        }
447
        if (pkt_type != PKT_MEDIA) {
448
            url_fskip(pb, pkt_len);
449
            continue;
450
        }
451
        if (pkt_len < 16) {
452
            av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
453
            continue;
454
        }
455
        pkt_len -= 16;
456
        track_type = get_byte(pb);
457
        track_id = get_byte(pb);
458
        field_nr = get_be32(pb);
459
        get_be32(pb); // field information
460
        get_be32(pb); // "timeline" field number
461
        get_byte(pb); // flags
462
        get_byte(pb); // reserved
463
        // NOTE: there is also data length information in the
464
        // field information, it might be better to take this into account
465
        // as well.
466
        ret = av_get_packet(pb, pkt, pkt_len);
467
        pkt->stream_index = get_sindex(s, track_id, track_type);
468
        pkt->pts = field_nr;
469
        return ret;
470
    }
471
    return AVERROR_IO;
472
}
473

    
474
static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
475
    uint64_t pos;
476
    uint64_t maxlen = 100 * 1024 * 1024;
477
    AVStream *st = s->streams[0];
478
    int64_t start_time = s->streams[stream_index]->start_time;
479
    int64_t found;
480
    int idx;
481
    if (timestamp < start_time) timestamp = start_time;
482
    idx = av_index_search_timestamp(st, timestamp - start_time,
483
                                    AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
484
    if (idx < 0)
485
        return -1;
486
    pos = st->index_entries[idx].pos;
487
    if (idx < st->nb_index_entries - 2)
488
        maxlen = st->index_entries[idx + 2].pos - pos;
489
    maxlen = FFMAX(maxlen, 200 * 1024);
490
    url_fseek(&s->pb, pos, SEEK_SET);
491
    found = gxf_resync_media(s, maxlen, -1, timestamp);
492
    if (ABS(found - timestamp) > 4)
493
        return -1;
494
    return 0;
495
}
496

    
497
static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
498
                                  int64_t *pos, int64_t pos_limit) {
499
    ByteIOContext *pb = &s->pb;
500
    int64_t res;
501
    url_fseek(pb, *pos, SEEK_SET);
502
    res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
503
    *pos = url_ftell(pb);
504
    return res;
505
}
506

    
507
AVInputFormat gxf_demuxer = {
508
    "gxf",
509
    "GXF format",
510
    0,
511
    gxf_probe,
512
    gxf_header,
513
    gxf_packet,
514
    NULL,
515
    gxf_seek,
516
    gxf_read_timestamp,
517
};