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1
/*
2
 * GXF demuxer.
3
 * Copyright (c) 2006 Reimar Doeffinger.
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
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21
#include "avformat.h"
22
#include "common.h"
23

    
24
typedef enum {
25
    PKT_MAP = 0xbc,
26
    PKT_MEDIA = 0xbf,
27
    PKT_EOS = 0xfb,
28
    PKT_FLT = 0xfc,
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    PKT_UMF = 0xfd
30
} pkt_type_t;
31

    
32
typedef enum {
33
    MAT_NAME = 0x40,
34
    MAT_FIRST_FIELD = 0x41,
35
    MAT_LAST_FIELD = 0x42,
36
    MAT_MARK_IN = 0x43,
37
    MAT_MARK_OUT = 0x44,
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    MAT_SIZE = 0x45
39
} mat_tag_t;
40

    
41
typedef enum {
42
    TRACK_NAME = 0x4c,
43
    TRACK_AUX = 0x4d,
44
    TRACK_VER = 0x4e,
45
    TRACK_MPG_AUX = 0x4f,
46
    TRACK_FPS = 0x50,
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    TRACK_LINES = 0x51,
48
    TRACK_FPF = 0x52
49
} track_tag_t;
50

    
51
typedef struct {
52
    int64_t first_field;
53
    int64_t last_field;
54
    AVRational frames_per_second;
55
    int32_t fields_per_frame;
56
} st_info_t;
57

    
58
/**
59
 * \brief parses a packet header, extracting type and length
60
 * \param pb ByteIOContext to read header from
61
 * \param type detected packet type is stored here
62
 * \param length detected packet length, excluding header is stored here
63
 * \return 0 if header not found or contains invalid data, 1 otherwise
64
 */
65
static int parse_packet_header(ByteIOContext *pb, pkt_type_t *type, int *length) {
66
    if (get_be32(pb))
67
        return 0;
68
    if (get_byte(pb) != 1)
69
        return 0;
70
    *type = get_byte(pb);
71
    *length = get_be32(pb);
72
    if ((*length >> 24) || *length < 16)
73
        return 0;
74
    *length -= 16;
75
    if (get_be32(pb))
76
        return 0;
77
    if (get_byte(pb) != 0xe1)
78
        return 0;
79
    if (get_byte(pb) != 0xe2)
80
        return 0;
81
    return 1;
82
}
83

    
84
/**
85
 * \brief check if file starts with a PKT_MAP header
86
 */
87
static int gxf_probe(AVProbeData *p) {
88
    static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
89
    static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
90
    if (p->buf_size < 16)
91
        return 0;
92
    if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
93
        !memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
94
        return AVPROBE_SCORE_MAX;
95
    return 0;
96
}
97

    
98
/**
99
 * \brief gets the stream index for the track with the specified id, creates new
100
 *        stream if not found
101
 * \param stream id of stream to find / add
102
 * \param format stream format identifier
103
 */
104
static int get_sindex(AVFormatContext *s, int id, int format) {
105
    int i;
106
    AVStream *st = NULL;
107
    for (i = 0; i < s->nb_streams; i++) {
108
        if (s->streams[i]->id == id)
109
            return i;
110
    }
111
    st = av_new_stream(s, id);
112
    switch (format) {
113
        case 3:
114
        case 4:
115
            st->codec->codec_type = CODEC_TYPE_VIDEO;
116
            st->codec->codec_id = CODEC_ID_MJPEG;
117
            break;
118
        case 13:
119
        case 15:
120
            st->codec->codec_type = CODEC_TYPE_VIDEO;
121
            st->codec->codec_id = CODEC_ID_DVVIDEO;
122
            break;
123
        case 14:
124
        case 16:
125
            st->codec->codec_type = CODEC_TYPE_VIDEO;
126
            st->codec->codec_id = CODEC_ID_DVVIDEO;
127
            break;
128
        case 11:
129
        case 12:
130
        case 20:
131
            st->codec->codec_type = CODEC_TYPE_VIDEO;
132
            st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
133
            st->need_parsing = 2; // get keyframe flag etc.
134
            break;
135
        case 22:
136
        case 23:
137
            st->codec->codec_type = CODEC_TYPE_VIDEO;
138
            st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
139
            st->need_parsing = 2; // get keyframe flag etc.
140
            break;
141
        case 9:
142
            st->codec->codec_type = CODEC_TYPE_AUDIO;
143
            st->codec->codec_id = CODEC_ID_PCM_S24LE;
144
            st->codec->channels = 1;
145
            st->codec->sample_rate = 48000;
146
            st->codec->bit_rate = 3 * 1 * 48000 * 8;
147
            st->codec->block_align = 3 * 1;
148
            st->codec->bits_per_sample = 24;
149
            break;
150
        case 10:
151
            st->codec->codec_type = CODEC_TYPE_AUDIO;
152
            st->codec->codec_id = CODEC_ID_PCM_S16LE;
153
            st->codec->channels = 1;
154
            st->codec->sample_rate = 48000;
155
            st->codec->bit_rate = 2 * 1 * 48000 * 8;
156
            st->codec->block_align = 2 * 1;
157
            st->codec->bits_per_sample = 16;
158
            break;
159
        case 17:
160
            st->codec->codec_type = CODEC_TYPE_AUDIO;
161
            st->codec->codec_id = CODEC_ID_AC3;
162
            st->codec->channels = 2;
163
            st->codec->sample_rate = 48000;
164
            break;
165
        default:
166
            st->codec->codec_type = CODEC_TYPE_UNKNOWN;
167
            st->codec->codec_id = CODEC_ID_NONE;
168
            break;
169
    }
170
    return s->nb_streams - 1;
171
}
172

    
173
/**
174
 * \brief filters out interesting tags from material information.
175
 * \param len lenght of tag section, will be adjusted to contain remaining bytes
176
 * \param si struct to store collected information into
177
 */
178
static void gxf_material_tags(ByteIOContext *pb, int *len, st_info_t *si) {
179
    si->first_field = AV_NOPTS_VALUE;
180
    si->last_field = AV_NOPTS_VALUE;
181
    while (*len >= 2) {
182
        mat_tag_t tag = get_byte(pb);
183
        int tlen = get_byte(pb);
184
        *len -= 2;
185
        if (tlen > *len)
186
            return;
187
        *len -= tlen;
188
        if (tlen == 4) {
189
            uint32_t value = get_be32(pb);
190
            if (tag == MAT_FIRST_FIELD)
191
                si->first_field = value;
192
            else if (tag == MAT_LAST_FIELD)
193
                si->last_field = value;
194
        } else
195
            url_fskip(pb, tlen);
196
    }
197
}
198

    
199
/**
200
 * \brief convert fps tag value to AVRational fps
201
 * \param fps fps value from tag
202
 * \return fps as AVRational, or 0 / 0 if unknown
203
 */
204
static AVRational fps_tag2avr(int32_t fps) {
205
    extern const AVRational ff_frame_rate_tab[];
206
    if (fps < 1 || fps > 9) fps = 9;
207
    return ff_frame_rate_tab[9 - fps]; // values have opposite order
208
}
209

    
210
/**
211
 * \brief convert UMF attributes flags to AVRational fps
212
 * \param fps fps value from flags
213
 * \return fps as AVRational, or 0 / 0 if unknown
214
 */
215
static AVRational fps_umf2avr(uint32_t flags) {
216
    static const AVRational map[] = {{50, 1}, {60000, 1001}, {24, 1},
217
        {25, 1}, {30000, 1001}};
218
    int idx =  av_log2((flags & 0x7c0) >> 6);
219
    return map[idx];
220
}
221

    
222
/**
223
 * \brief filters out interesting tags from track information.
224
 * \param len length of tag section, will be adjusted to contain remaining bytes
225
 * \param si struct to store collected information into
226
 */
227
static void gxf_track_tags(ByteIOContext *pb, int *len, st_info_t *si) {
228
    si->frames_per_second = (AVRational){0, 0};
229
    si->fields_per_frame = 0;
230
    while (*len >= 2) {
231
        track_tag_t tag = get_byte(pb);
232
        int tlen = get_byte(pb);
233
        *len -= 2;
234
        if (tlen > *len)
235
            return;
236
        *len -= tlen;
237
        if (tlen == 4) {
238
            uint32_t value = get_be32(pb);
239
            if (tag == TRACK_FPS)
240
                si->frames_per_second = fps_tag2avr(value);
241
            else if (tag == TRACK_FPF && (value == 1 || value == 2))
242
                si->fields_per_frame = value;
243
        } else
244
            url_fskip(pb, tlen);
245
    }
246
}
247

    
248
/**
249
 * \brief read index from FLT packet into stream 0 av_index
250
 */
251
static void gxf_read_index(AVFormatContext *s, int pkt_len) {
252
    ByteIOContext *pb = &s->pb;
253
    AVStream *st = s->streams[0];
254
    uint32_t fields_per_map = get_le32(pb);
255
    uint32_t map_cnt = get_le32(pb);
256
    int i;
257
    pkt_len -= 8;
258
    if (map_cnt > 1000) {
259
        av_log(s, AV_LOG_ERROR, "GXF: too many index entries %u (%x)\n", map_cnt, map_cnt);
260
        map_cnt = 1000;
261
    }
262
    if (pkt_len < 4 * map_cnt) {
263
        av_log(s, AV_LOG_ERROR, "GXF: invalid index length\n");
264
        url_fskip(pb, pkt_len);
265
        return;
266
    }
267
    pkt_len -= 4 * map_cnt;
268
    av_add_index_entry(st, 0, 0, 0, 0, 0);
269
    for (i = 0; i < map_cnt; i++)
270
        av_add_index_entry(st, (uint64_t)get_le32(pb) * 1024,
271
                           i * (uint64_t)fields_per_map + 1, 0, 0, 0);
272
    url_fskip(pb, pkt_len);
273
}
274

    
275
static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
276
    ByteIOContext *pb = &s->pb;
277
    pkt_type_t pkt_type;
278
    int map_len;
279
    int len;
280
    AVRational main_timebase = {0, 0};
281
    st_info_t si;
282
    int i;
283
    if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
284
        av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
285
        return 0;
286
    }
287
    map_len -= 2;
288
    if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
289
        av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
290
        return 0;
291
    }
292
    map_len -= 2;
293
    len = get_be16(pb); // length of material data section
294
    if (len > map_len) {
295
        av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
296
        return 0;
297
    }
298
    map_len -= len;
299
    gxf_material_tags(pb, &len, &si);
300
    url_fskip(pb, len);
301
    map_len -= 2;
302
    len = get_be16(pb); // length of track description
303
    if (len > map_len) {
304
        av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
305
        return 0;
306
    }
307
    map_len -= len;
308
    while (len > 0) {
309
        int track_type, track_id, track_len;
310
        AVStream *st;
311
        int idx;
312
        len -= 4;
313
        track_type = get_byte(pb);
314
        track_id = get_byte(pb);
315
        track_len = get_be16(pb);
316
        len -= track_len;
317
        gxf_track_tags(pb, &track_len, &si);
318
        url_fskip(pb, track_len);
319
        if (!(track_type & 0x80)) {
320
           av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
321
           continue;
322
        }
323
        track_type &= 0x7f;
324
        if ((track_id & 0xc0) != 0xc0) {
325
           av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
326
           continue;
327
        }
328
        track_id &= 0x3f;
329
        idx = get_sindex(s, track_id, track_type);
330
        if (idx < 0) continue;
331
        st = s->streams[idx];
332
        if (!main_timebase.num || !main_timebase.den) {
333
            main_timebase.num = si.frames_per_second.den;
334
            main_timebase.den = si.frames_per_second.num * si.fields_per_frame;
335
        }
336
        st->start_time = si.first_field;
337
        if (si.first_field != AV_NOPTS_VALUE && si.last_field != AV_NOPTS_VALUE)
338
            st->duration = si.last_field - si.first_field;
339
    }
340
    if (len < 0)
341
        av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
342
    if (map_len)
343
        url_fskip(pb, map_len);
344
    if (!parse_packet_header(pb, &pkt_type, &len)) {
345
        av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
346
        return -1;
347
    }
348
    if (pkt_type == PKT_FLT) {
349
        gxf_read_index(s, len);
350
        if (!parse_packet_header(pb, &pkt_type, &len)) {
351
            av_log(s, AV_LOG_ERROR, "GXF: sync lost in header\n");
352
            return -1;
353
        }
354
    }
355
    if (pkt_type == PKT_UMF) {
356
        if (len >= 9) {
357
            AVRational fps;
358
            len -= 9;
359
            url_fskip(pb, 5);
360
            fps = fps_umf2avr(get_le32(pb));
361
            if (!main_timebase.num || !main_timebase.den) {
362
                // this may not always be correct, but simply the best we can get
363
                main_timebase.num = fps.den;
364
                main_timebase.den = fps.num;
365
            }
366
        } else
367
            av_log(s, AV_LOG_INFO, "GXF: UMF packet too short\n");
368
    } else
369
        av_log(s, AV_LOG_INFO, "GXF: UMF packet missing\n");
370
    url_fskip(pb, len);
371
    for (i = 0; i < s->nb_streams; i++) {
372
        AVStream *st = s->streams[i];
373
        if (main_timebase.num && main_timebase.den)
374
            st->time_base = main_timebase;
375
        else {
376
            st->start_time = st->duration = AV_NOPTS_VALUE;
377
        }
378
    }
379
    return 0;
380
}
381

    
382
#define READ_ONE() \
383
    { \
384
        if (!max_interval-- || url_feof(pb)) \
385
            goto out; \
386
        tmp = tmp << 8 | get_byte(pb); \
387
    }
388

    
389
/**
390
 * \brief resync the stream on the next media packet with specified properties
391
 * \param max_interval how many bytes to search for matching packet at most
392
 * \param track track id the media packet must belong to, -1 for any
393
 * \param timestamp minimum timestamp (== field number) the packet must have, -1 for any
394
 * \return timestamp of packet found
395
 */
396
static int64_t gxf_resync_media(AVFormatContext *s, uint64_t max_interval, int track, int timestamp) {
397
    uint32_t tmp;
398
    uint64_t last_pos;
399
    uint64_t last_found_pos = 0;
400
    int cur_track;
401
    int64_t cur_timestamp = AV_NOPTS_VALUE;
402
    int len;
403
    ByteIOContext *pb = &s->pb;
404
    pkt_type_t type;
405
    tmp = get_be32(pb);
406
start:
407
    while (tmp)
408
        READ_ONE();
409
    READ_ONE();
410
    if (tmp != 1)
411
        goto start;
412
    last_pos = url_ftell(pb);
413
    url_fseek(pb, -5, SEEK_CUR);
414
    if (!parse_packet_header(pb, &type, &len) || type != PKT_MEDIA) {
415
        url_fseek(pb, last_pos, SEEK_SET);
416
        goto start;
417
    }
418
    get_byte(pb);
419
    cur_track = get_byte(pb);
420
    cur_timestamp = get_be32(pb);
421
    last_found_pos = url_ftell(pb) - 16 - 6;
422
    if ((track >= 0 && track != cur_track) || (timestamp >= 0 && timestamp > cur_timestamp)) {
423
        url_fseek(pb, last_pos, SEEK_SET);
424
        goto start;
425
    }
426
out:
427
    if (last_found_pos)
428
        url_fseek(pb, last_found_pos, SEEK_SET);
429
    return cur_timestamp;
430
}
431

    
432
static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
433
    ByteIOContext *pb = &s->pb;
434
    pkt_type_t pkt_type;
435
    int pkt_len;
436
    while (!url_feof(pb)) {
437
        int track_type, track_id, ret;
438
        int field_nr;
439
        if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
440
            if (!url_feof(pb))
441
                av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
442
            return -1;
443
        }
444
        if (pkt_type == PKT_FLT) {
445
            gxf_read_index(s, pkt_len);
446
            continue;
447
        }
448
        if (pkt_type != PKT_MEDIA) {
449
            url_fskip(pb, pkt_len);
450
            continue;
451
        }
452
        if (pkt_len < 16) {
453
            av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
454
            continue;
455
        }
456
        pkt_len -= 16;
457
        track_type = get_byte(pb);
458
        track_id = get_byte(pb);
459
        field_nr = get_be32(pb);
460
        get_be32(pb); // field information
461
        get_be32(pb); // "timeline" field number
462
        get_byte(pb); // flags
463
        get_byte(pb); // reserved
464
        // NOTE: there is also data length information in the
465
        // field information, it might be better to take this into account
466
        // as well.
467
        ret = av_get_packet(pb, pkt, pkt_len);
468
        pkt->stream_index = get_sindex(s, track_id, track_type);
469
        pkt->dts = field_nr;
470
        return ret;
471
    }
472
    return AVERROR_IO;
473
}
474

    
475
static int gxf_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) {
476
    uint64_t pos;
477
    uint64_t maxlen = 100 * 1024 * 1024;
478
    AVStream *st = s->streams[0];
479
    int64_t start_time = s->streams[stream_index]->start_time;
480
    int64_t found;
481
    int idx;
482
    if (timestamp < start_time) timestamp = start_time;
483
    idx = av_index_search_timestamp(st, timestamp - start_time,
484
                                    AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
485
    if (idx < 0)
486
        return -1;
487
    pos = st->index_entries[idx].pos;
488
    if (idx < st->nb_index_entries - 2)
489
        maxlen = st->index_entries[idx + 2].pos - pos;
490
    maxlen = FFMAX(maxlen, 200 * 1024);
491
    url_fseek(&s->pb, pos, SEEK_SET);
492
    found = gxf_resync_media(s, maxlen, -1, timestamp);
493
    if (FFABS(found - timestamp) > 4)
494
        return -1;
495
    return 0;
496
}
497

    
498
static int64_t gxf_read_timestamp(AVFormatContext *s, int stream_index,
499
                                  int64_t *pos, int64_t pos_limit) {
500
    ByteIOContext *pb = &s->pb;
501
    int64_t res;
502
    url_fseek(pb, *pos, SEEK_SET);
503
    res = gxf_resync_media(s, pos_limit - *pos, -1, -1);
504
    *pos = url_ftell(pb);
505
    return res;
506
}
507

    
508
AVInputFormat gxf_demuxer = {
509
    "gxf",
510
    "GXF format",
511
    0,
512
    gxf_probe,
513
    gxf_header,
514
    gxf_packet,
515
    NULL,
516
    gxf_seek,
517
    gxf_read_timestamp,
518
};