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ffmpeg / libavformat / ffm.c @ 34f633df

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1
/*
2
 * FFM (ffserver live feed) encoder and decoder
3
 * Copyright (c) 2001 Fabrice Bellard.
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
 *
10
 * 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
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
#include "avformat.h"
20
#include <unistd.h>
21

    
22
/* The FFM file is made of blocks of fixed size */
23
#define FFM_HEADER_SIZE 14
24
#define PACKET_ID       0x666d
25

    
26
/* each packet contains frames (which can span several packets */
27
#define FRAME_HEADER_SIZE    8
28
#define FLAG_KEY_FRAME       0x01
29

    
30
typedef struct FFMStream {
31
    int64_t pts;
32
} FFMStream;
33

    
34
enum {
35
    READ_HEADER,
36
    READ_DATA,
37
};
38

    
39
typedef struct FFMContext {
40
    /* only reading mode */
41
    offset_t write_index, file_size;
42
    int read_state;
43
    uint8_t header[FRAME_HEADER_SIZE];
44

    
45
    /* read and write */
46
    int first_packet; /* true if first packet, needed to set the discontinuity tag */
47
    int packet_size;
48
    int frame_offset;
49
    int64_t pts;
50
    uint8_t *packet_ptr, *packet_end;
51
    uint8_t packet[FFM_PACKET_SIZE];
52
} FFMContext;
53

    
54
static int64_t get_pts(AVFormatContext *s, offset_t pos);
55

    
56
/* disable pts hack for testing */
57
int ffm_nopts = 0;
58

    
59
#ifdef CONFIG_ENCODERS
60
static void flush_packet(AVFormatContext *s)
61
{
62
    FFMContext *ffm = s->priv_data;
63
    int fill_size, h;
64
    ByteIOContext *pb = &s->pb;
65

    
66
    fill_size = ffm->packet_end - ffm->packet_ptr;
67
    memset(ffm->packet_ptr, 0, fill_size);
68

    
69
    if (url_ftell(pb) % ffm->packet_size) 
70
        av_abort();
71

    
72
    /* put header */
73
    put_be16(pb, PACKET_ID);
74
    put_be16(pb, fill_size);
75
    put_be64(pb, ffm->pts);
76
    h = ffm->frame_offset;
77
    if (ffm->first_packet)
78
        h |= 0x8000;
79
    put_be16(pb, h);
80
    put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
81
    put_flush_packet(pb);
82

    
83
    /* prepare next packet */
84
    ffm->frame_offset = 0; /* no key frame */
85
    ffm->pts = 0; /* no pts */
86
    ffm->packet_ptr = ffm->packet;
87
    ffm->first_packet = 0;
88
}
89

    
90
/* 'first' is true if first data of a frame */
91
static void ffm_write_data(AVFormatContext *s,
92
                           const uint8_t *buf, int size,
93
                           int64_t pts, int first)
94
{
95
    FFMContext *ffm = s->priv_data;
96
    int len;
97

    
98
    if (first && ffm->frame_offset == 0)
99
        ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
100
    if (first && ffm->pts == 0)
101
        ffm->pts = pts;
102

    
103
    /* write as many packets as needed */
104
    while (size > 0) {
105
        len = ffm->packet_end - ffm->packet_ptr;
106
        if (len > size)
107
            len = size;
108
        memcpy(ffm->packet_ptr, buf, len);
109

    
110
        ffm->packet_ptr += len;
111
        buf += len;
112
        size -= len;
113
        if (ffm->packet_ptr >= ffm->packet_end) {
114
            /* special case : no pts in packet : we leave the current one */
115
            if (ffm->pts == 0)
116
                ffm->pts = pts;
117

    
118
            flush_packet(s);
119
        }
120
    }
121
}
122

    
123
static int ffm_write_header(AVFormatContext *s)
124
{
125
    FFMContext *ffm = s->priv_data;
126
    AVStream *st;
127
    FFMStream *fst;
128
    ByteIOContext *pb = &s->pb;
129
    AVCodecContext *codec;
130
    int bit_rate, i;
131

    
132
    ffm->packet_size = FFM_PACKET_SIZE;
133

    
134
    /* header */
135
    put_tag(pb, "FFM1");
136
    put_be32(pb, ffm->packet_size);
137
    /* XXX: store write position in other file ? */
138
    put_be64(pb, ffm->packet_size); /* current write position */
139

    
140
    put_be32(pb, s->nb_streams);
141
    bit_rate = 0;
142
    for(i=0;i<s->nb_streams;i++) {
143
        st = s->streams[i];
144
        bit_rate += st->codec.bit_rate;
145
    }
146
    put_be32(pb, bit_rate);
147

    
148
    /* list of streams */
149
    for(i=0;i<s->nb_streams;i++) {
150
        st = s->streams[i];
151
        fst = av_mallocz(sizeof(FFMStream));
152
        if (!fst)
153
            goto fail;
154
        av_set_pts_info(st, 64, 1, 1000000);
155
        st->priv_data = fst;
156

    
157
        codec = &st->codec;
158
        /* generic info */
159
        put_be32(pb, codec->codec_id);
160
        put_byte(pb, codec->codec_type);
161
        put_be32(pb, codec->bit_rate);
162
        put_be32(pb, st->quality);
163
        put_be32(pb, codec->flags);
164
        put_be32(pb, codec->flags2);
165
        put_be32(pb, codec->debug);
166
        /* specific info */
167
        switch(codec->codec_type) {
168
        case CODEC_TYPE_VIDEO:
169
            put_be32(pb, codec->time_base.num);
170
            put_be32(pb, codec->time_base.den);
171
            put_be16(pb, codec->width);
172
            put_be16(pb, codec->height);
173
            put_be16(pb, codec->gop_size);
174
            put_be32(pb, codec->pix_fmt);
175
            put_byte(pb, codec->qmin);
176
            put_byte(pb, codec->qmax);
177
            put_byte(pb, codec->max_qdiff);
178
            put_be16(pb, (int) (codec->qcompress * 10000.0));
179
            put_be16(pb, (int) (codec->qblur * 10000.0));
180
            put_be32(pb, codec->bit_rate_tolerance);
181
            put_strz(pb, codec->rc_eq);
182
            put_be32(pb, codec->rc_max_rate);
183
            put_be32(pb, codec->rc_min_rate);
184
            put_be32(pb, codec->rc_buffer_size);
185
            put_be64_double(pb, codec->i_quant_factor);
186
            put_be64_double(pb, codec->b_quant_factor);
187
            put_be64_double(pb, codec->i_quant_offset);
188
            put_be64_double(pb, codec->b_quant_offset);
189
            put_be32(pb, codec->dct_algo);
190
            put_be32(pb, codec->strict_std_compliance);
191
            put_be32(pb, codec->max_b_frames);
192
            put_be32(pb, codec->luma_elim_threshold);
193
            put_be32(pb, codec->chroma_elim_threshold);
194
            put_be32(pb, codec->mpeg_quant);
195
            put_be32(pb, codec->intra_dc_precision);
196
            put_be32(pb, codec->me_method);
197
            put_be32(pb, codec->mb_decision);
198
            put_be32(pb, codec->nsse_weight);
199
            put_be32(pb, codec->frame_skip_cmp);
200
            put_be64_double(pb, codec->rc_buffer_aggressivity);
201
            break;
202
        case CODEC_TYPE_AUDIO:
203
            put_be32(pb, codec->sample_rate);
204
            put_le16(pb, codec->channels);
205
            put_le16(pb, codec->frame_size);
206
            break;
207
        default:
208
            return -1;
209
        }
210
        /* hack to have real time */
211
        if (ffm_nopts)
212
            fst->pts = 0;
213
        else
214
            fst->pts = av_gettime();
215
    }
216

    
217
    /* flush until end of block reached */
218
    while ((url_ftell(pb) % ffm->packet_size) != 0)
219
        put_byte(pb, 0);
220

    
221
    put_flush_packet(pb);
222

    
223
    /* init packet mux */
224
    ffm->packet_ptr = ffm->packet;
225
    ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
226
    assert(ffm->packet_end >= ffm->packet);
227
    ffm->frame_offset = 0;
228
    ffm->pts = 0;
229
    ffm->first_packet = 1;
230

    
231
    return 0;
232
 fail:
233
    for(i=0;i<s->nb_streams;i++) {
234
        st = s->streams[i];
235
        av_freep(&st->priv_data);
236
    }
237
    return -1;
238
}
239

    
240
static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
241
{
242
    AVStream *st = s->streams[pkt->stream_index];
243
    FFMStream *fst = st->priv_data;
244
    int64_t pts;
245
    uint8_t header[FRAME_HEADER_SIZE];
246
    int duration;
247
    int size= pkt->size;
248

    
249
    //XXX/FIXME use duration from pkt
250
    if (st->codec.codec_type == CODEC_TYPE_AUDIO) {
251
        duration = ((float)st->codec.frame_size / st->codec.sample_rate * 1000000.0);
252
    } else {
253
        duration = (1000000.0 * st->codec.time_base.num / (float)st->codec.time_base.den);
254
    }
255

    
256
    pts = fst->pts;
257
    /* packet size & key_frame */
258
    header[0] = pkt->stream_index;
259
    header[1] = 0;
260
    if (pkt->flags & PKT_FLAG_KEY)
261
        header[1] |= FLAG_KEY_FRAME;
262
    header[2] = (size >> 16) & 0xff;
263
    header[3] = (size >> 8) & 0xff;
264
    header[4] = size & 0xff;
265
    header[5] = (duration >> 16) & 0xff;
266
    header[6] = (duration >> 8) & 0xff;
267
    header[7] = duration & 0xff;
268
    ffm_write_data(s, header, FRAME_HEADER_SIZE, pts, 1);
269
    ffm_write_data(s, pkt->data, size, pts, 0);
270

    
271
    fst->pts += duration;
272
    return 0;
273
}
274

    
275
static int ffm_write_trailer(AVFormatContext *s)
276
{
277
    ByteIOContext *pb = &s->pb;
278
    FFMContext *ffm = s->priv_data;
279

    
280
    /* flush packets */
281
    if (ffm->packet_ptr > ffm->packet)
282
        flush_packet(s);
283

    
284
    put_flush_packet(pb);
285

    
286
    if (!url_is_streamed(pb)) {
287
        int64_t size;
288
        /* update the write offset */
289
        size = url_ftell(pb);
290
        url_fseek(pb, 8, SEEK_SET);
291
        put_be64(pb, size);
292
        put_flush_packet(pb);
293
    }
294

    
295
    return 0;
296
}
297
#endif //CONFIG_ENCODERS
298

    
299
/* ffm demux */
300

    
301
static int ffm_is_avail_data(AVFormatContext *s, int size)
302
{
303
    FFMContext *ffm = s->priv_data;
304
    offset_t pos, avail_size;
305
    int len;
306

    
307
    len = ffm->packet_end - ffm->packet_ptr;
308
    if (!ffm_nopts) {
309
        /* XXX: I don't understand this test, so I disabled it for testing */
310
        if (size <= len)
311
            return 1;
312
    }
313
    pos = url_ftell(&s->pb);
314
    if (pos == ffm->write_index) {
315
        /* exactly at the end of stream */
316
        return 0;
317
    } else if (pos < ffm->write_index) {
318
        avail_size = ffm->write_index - pos;
319
    } else {
320
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
321
    }
322
    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
323
    if (size <= avail_size)
324
        return 1;
325
    else
326
        return 0;
327
}
328

    
329
/* first is true if we read the frame header */
330
static int ffm_read_data(AVFormatContext *s,
331
                         uint8_t *buf, int size, int first)
332
{
333
    FFMContext *ffm = s->priv_data;
334
    ByteIOContext *pb = &s->pb;
335
    int len, fill_size, size1, frame_offset;
336

    
337
    size1 = size;
338
    while (size > 0) {
339
    redo:
340
        len = ffm->packet_end - ffm->packet_ptr;
341
        if (len > size)
342
            len = size;
343
        if (len == 0) {
344
            if (url_ftell(pb) == ffm->file_size)
345
                url_fseek(pb, ffm->packet_size, SEEK_SET);
346
    retry_read:
347
            get_be16(pb); /* PACKET_ID */
348
            fill_size = get_be16(pb);
349
            ffm->pts = get_be64(pb);
350
            frame_offset = get_be16(pb);
351
            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
352
            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
353
            if (ffm->packet_end < ffm->packet)
354
                return -1;
355
            /* if first packet or resynchronization packet, we must
356
               handle it specifically */
357
            if (ffm->first_packet || (frame_offset & 0x8000)) {
358
                if (!frame_offset) {
359
                    /* This packet has no frame headers in it */
360
                    if (url_ftell(pb) >= ffm->packet_size * 3) {
361
                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
362
                        goto retry_read;
363
                    }
364
                    /* This is bad, we cannot find a valid frame header */
365
                    return 0;
366
                }
367
                ffm->first_packet = 0;
368
                if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
369
                    return -1;
370
                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
371
                if (!first)
372
                    break;
373
            } else {
374
                ffm->packet_ptr = ffm->packet;
375
            }
376
            goto redo;
377
        }
378
        memcpy(buf, ffm->packet_ptr, len);
379
        buf += len;
380
        ffm->packet_ptr += len;
381
        size -= len;
382
        first = 0;
383
    }
384
    return size1 - size;
385
}
386

    
387

    
388
static void adjust_write_index(AVFormatContext *s)
389
{
390
    FFMContext *ffm = s->priv_data;
391
    ByteIOContext *pb = &s->pb;
392
    int64_t pts;
393
    //offset_t orig_write_index = ffm->write_index;
394
    offset_t pos_min, pos_max;
395
    int64_t pts_start;
396
    offset_t ptr = url_ftell(pb);
397

    
398

    
399
    pos_min = 0;
400
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
401

    
402
    pts_start = get_pts(s, pos_min);
403

    
404
    pts = get_pts(s, pos_max);
405

    
406
    if (pts - 100000 > pts_start) 
407
        goto end;
408

    
409
    ffm->write_index = FFM_PACKET_SIZE;
410

    
411
    pts_start = get_pts(s, pos_min);
412

    
413
    pts = get_pts(s, pos_max);
414

    
415
    if (pts - 100000 <= pts_start) {
416
        while (1) {
417
            offset_t newpos;
418
            int64_t newpts;
419

    
420
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
421

    
422
            if (newpos == pos_min)
423
                break;
424

    
425
            newpts = get_pts(s, newpos);
426

    
427
            if (newpts - 100000 <= pts) {
428
                pos_max = newpos;
429
                pts = newpts;
430
            } else {
431
                pos_min = newpos;
432
            }
433
        }
434
        ffm->write_index += pos_max;
435
    }
436

    
437
    //printf("Adjusted write index from %lld to %lld: pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
438
    //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
439

    
440
 end:
441
    url_fseek(pb, ptr, SEEK_SET);
442
}
443

    
444

    
445
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
446
{
447
    FFMContext *ffm = s->priv_data;
448
    AVStream *st;
449
    FFMStream *fst;
450
    ByteIOContext *pb = &s->pb;
451
    AVCodecContext *codec;
452
    int i, nb_streams;
453
    uint32_t tag;
454

    
455
    /* header */
456
    tag = get_le32(pb);
457
    if (tag != MKTAG('F', 'F', 'M', '1'))
458
        goto fail;
459
    ffm->packet_size = get_be32(pb);
460
    if (ffm->packet_size != FFM_PACKET_SIZE)
461
        goto fail;
462
    ffm->write_index = get_be64(pb);
463
    /* get also filesize */
464
    if (!url_is_streamed(pb)) {
465
        ffm->file_size = url_filesize(url_fileno(pb));
466
        adjust_write_index(s);
467
    } else {
468
        ffm->file_size = (uint64_t_C(1) << 63) - 1;
469
    }
470

    
471
    nb_streams = get_be32(pb);
472
    get_be32(pb); /* total bitrate */
473
    /* read each stream */
474
    for(i=0;i<nb_streams;i++) {
475
        char rc_eq_buf[128];
476

    
477
        st = av_new_stream(s, 0);
478
        if (!st)
479
            goto fail;
480
        fst = av_mallocz(sizeof(FFMStream));
481
        if (!fst)
482
            goto fail;
483
            
484
        av_set_pts_info(st, 64, 1, 1000000);
485
            
486
        st->priv_data = fst;
487

    
488
        codec = &st->codec;
489
        /* generic info */
490
        st->codec.codec_id = get_be32(pb);
491
        st->codec.codec_type = get_byte(pb); /* codec_type */
492
        codec->bit_rate = get_be32(pb);
493
        st->quality = get_be32(pb);
494
        codec->flags = get_be32(pb);
495
        codec->flags2 = get_be32(pb);
496
        codec->debug = get_be32(pb);
497
        /* specific info */
498
        switch(codec->codec_type) {
499
        case CODEC_TYPE_VIDEO:
500
            codec->time_base.num = get_be32(pb);
501
            codec->time_base.den = get_be32(pb);
502
            codec->width = get_be16(pb);
503
            codec->height = get_be16(pb);
504
            codec->gop_size = get_be16(pb);
505
            codec->pix_fmt = get_be32(pb);
506
            codec->qmin = get_byte(pb);
507
            codec->qmax = get_byte(pb);
508
            codec->max_qdiff = get_byte(pb);
509
            codec->qcompress = get_be16(pb) / 10000.0;
510
            codec->qblur = get_be16(pb) / 10000.0;
511
            codec->bit_rate_tolerance = get_be32(pb);
512
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
513
            codec->rc_max_rate = get_be32(pb);
514
            codec->rc_min_rate = get_be32(pb);
515
            codec->rc_buffer_size = get_be32(pb);
516
            codec->i_quant_factor = get_be64_double(pb);
517
            codec->b_quant_factor = get_be64_double(pb);
518
            codec->i_quant_offset = get_be64_double(pb);
519
            codec->b_quant_offset = get_be64_double(pb);
520
            codec->dct_algo = get_be32(pb);
521
            codec->strict_std_compliance = get_be32(pb);
522
            codec->max_b_frames = get_be32(pb);
523
            codec->luma_elim_threshold = get_be32(pb);
524
            codec->chroma_elim_threshold = get_be32(pb);
525
            codec->mpeg_quant = get_be32(pb);
526
            codec->intra_dc_precision = get_be32(pb);
527
            codec->me_method = get_be32(pb);
528
            codec->mb_decision = get_be32(pb);
529
            codec->nsse_weight = get_be32(pb);
530
            codec->frame_skip_cmp = get_be32(pb);
531
            codec->rc_buffer_aggressivity = get_be64_double(pb);
532
            break;
533
        case CODEC_TYPE_AUDIO:
534
            codec->sample_rate = get_be32(pb);
535
            codec->channels = get_le16(pb);
536
            codec->frame_size = get_le16(pb);
537
            break;
538
        default:
539
            goto fail;
540
        }
541

    
542
    }
543

    
544
    /* get until end of block reached */
545
    while ((url_ftell(pb) % ffm->packet_size) != 0)
546
        get_byte(pb);
547

    
548
    /* init packet demux */
549
    ffm->packet_ptr = ffm->packet;
550
    ffm->packet_end = ffm->packet;
551
    ffm->frame_offset = 0;
552
    ffm->pts = 0;
553
    ffm->read_state = READ_HEADER;
554
    ffm->first_packet = 1;
555
    return 0;
556
 fail:
557
    for(i=0;i<s->nb_streams;i++) {
558
        st = s->streams[i];
559
        if (st) {
560
            av_freep(&st->priv_data);
561
            av_free(st);
562
        }
563
    }
564
    return -1;
565
}
566

    
567
/* return < 0 if eof */
568
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
569
{
570
    int size;
571
    FFMContext *ffm = s->priv_data;
572
    int duration;
573

    
574
    switch(ffm->read_state) {
575
    case READ_HEADER:
576
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
577
            return -EAGAIN;
578
        }
579
#if 0
580
        printf("pos=%08Lx spos=%Lx, write_index=%Lx size=%Lx\n",
581
               url_ftell(&s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
582
#endif
583
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) != 
584
            FRAME_HEADER_SIZE)
585
            return -EAGAIN;
586
#if 0
587
        {
588
            int i;
589
            for(i=0;i<FRAME_HEADER_SIZE;i++)
590
                printf("%02x ", ffm->header[i]);
591
            printf("\n");
592
        }
593
#endif
594
        ffm->read_state = READ_DATA;
595
        /* fall thru */
596
    case READ_DATA:
597
        size = (ffm->header[2] << 16) | (ffm->header[3] << 8) | ffm->header[4];
598
        if (!ffm_is_avail_data(s, size)) {
599
            return -EAGAIN;
600
        }
601

    
602
        duration = (ffm->header[5] << 16) | (ffm->header[6] << 8) | ffm->header[7];
603

    
604
        av_new_packet(pkt, size);
605
        pkt->stream_index = ffm->header[0];
606
        if (ffm->header[1] & FLAG_KEY_FRAME)
607
            pkt->flags |= PKT_FLAG_KEY;
608

    
609
        ffm->read_state = READ_HEADER;
610
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
611
            /* bad case: desynchronized packet. we cancel all the packet loading */
612
            av_free_packet(pkt);
613
            return -EAGAIN;
614
        }
615
        pkt->pts = ffm->pts;
616
        pkt->duration = duration;
617
        break;
618
    }
619
    return 0;
620
}
621

    
622
//#define DEBUG_SEEK
623

    
624
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
625
   by the write position inside this function */
626
static void ffm_seek1(AVFormatContext *s, offset_t pos1)
627
{
628
    FFMContext *ffm = s->priv_data;
629
    ByteIOContext *pb = &s->pb;
630
    offset_t pos;
631

    
632
    pos = pos1 + ffm->write_index;
633
    if (pos >= ffm->file_size)
634
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
635
#ifdef DEBUG_SEEK
636
    printf("seek to %Lx -> %Lx\n", pos1, pos);
637
#endif
638
    url_fseek(pb, pos, SEEK_SET);
639
}
640

    
641
static int64_t get_pts(AVFormatContext *s, offset_t pos)
642
{
643
    ByteIOContext *pb = &s->pb;
644
    int64_t pts;
645

    
646
    ffm_seek1(s, pos);
647
    url_fskip(pb, 4);
648
    pts = get_be64(pb);
649
#ifdef DEBUG_SEEK
650
    printf("pts=%0.6f\n", pts / 1000000.0);
651
#endif
652
    return pts;
653
}
654

    
655
/* seek to a given time in the file. The file read pointer is
656
   positionned at or before pts. XXX: the following code is quite
657
   approximative */
658
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
659
{
660
    FFMContext *ffm = s->priv_data;
661
    offset_t pos_min, pos_max, pos;
662
    int64_t pts_min, pts_max, pts;
663
    double pos1;
664

    
665
#ifdef DEBUG_SEEK
666
    printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
667
#endif
668
    /* find the position using linear interpolation (better than
669
       dichotomy in typical cases) */
670
    pos_min = 0;
671
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
672
    while (pos_min <= pos_max) {
673
        pts_min = get_pts(s, pos_min);
674
        pts_max = get_pts(s, pos_max);
675
        /* linear interpolation */
676
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
677
            (double)(pts_max - pts_min);
678
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
679
        if (pos <= pos_min)
680
            pos = pos_min;
681
        else if (pos >= pos_max)
682
            pos = pos_max;
683
        pts = get_pts(s, pos);
684
        /* check if we are lucky */
685
        if (pts == wanted_pts) {
686
            goto found;
687
        } else if (pts > wanted_pts) {
688
            pos_max = pos - FFM_PACKET_SIZE;
689
        } else {
690
            pos_min = pos + FFM_PACKET_SIZE;
691
        }
692
    }
693
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
694
    if (pos > 0)
695
        pos -= FFM_PACKET_SIZE;
696
 found:
697
    ffm_seek1(s, pos);
698
    return 0;
699
}
700

    
701
offset_t ffm_read_write_index(int fd)
702
{
703
    uint8_t buf[8];
704
    offset_t pos;
705
    int i;
706

    
707
    lseek(fd, 8, SEEK_SET);
708
    read(fd, buf, 8);
709
    pos = 0;
710
    for(i=0;i<8;i++)
711
        pos |= (int64_t)buf[i] << (56 - i * 8);
712
    return pos;
713
}
714

    
715
void ffm_write_write_index(int fd, offset_t pos)
716
{
717
    uint8_t buf[8];
718
    int i;
719

    
720
    for(i=0;i<8;i++)
721
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
722
    lseek(fd, 8, SEEK_SET);
723
    write(fd, buf, 8);
724
}
725

    
726
void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
727
{
728
    FFMContext *ffm = s->priv_data;
729
    ffm->write_index = pos;
730
    ffm->file_size = file_size;
731
}
732

    
733
static int ffm_read_close(AVFormatContext *s)
734
{
735
    AVStream *st;
736
    int i;
737

    
738
    for(i=0;i<s->nb_streams;i++) {
739
        st = s->streams[i];
740
        av_freep(&st->priv_data);
741
    }
742
    return 0;
743
}
744

    
745
static int ffm_probe(AVProbeData *p)
746
{
747
    if (p->buf_size >= 4 &&
748
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' && 
749
        p->buf[3] == '1')
750
        return AVPROBE_SCORE_MAX + 1;
751
    return 0;
752
}
753

    
754
static AVInputFormat ffm_iformat = {
755
    "ffm",
756
    "ffm format",
757
    sizeof(FFMContext),
758
    ffm_probe,
759
    ffm_read_header,
760
    ffm_read_packet,
761
    ffm_read_close,
762
    ffm_seek,
763
};
764

    
765
#ifdef CONFIG_ENCODERS
766
static AVOutputFormat ffm_oformat = {
767
    "ffm",
768
    "ffm format",
769
    "",
770
    "ffm",
771
    sizeof(FFMContext),
772
    /* not really used */
773
    CODEC_ID_MP2,
774
    CODEC_ID_MPEG1VIDEO,
775
    ffm_write_header,
776
    ffm_write_packet,
777
    ffm_write_trailer,
778
};
779
#endif //CONFIG_ENCODERS
780

    
781
int ffm_init(void)
782
{
783
    av_register_input_format(&ffm_iformat);
784
#ifdef CONFIG_ENCODERS
785
    av_register_output_format(&ffm_oformat);
786
#endif //CONFIG_ENCODERS
787
    return 0;
788
}