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ffmpeg / libavformat / ffmdec.c @ d2b34efe

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1
/*
2
 * FFM (ffserver live feed) demuxer
3
 * Copyright (c) 2001 Fabrice Bellard
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
 *
12
 * 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.
16
 *
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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
#include "libavutil/intreadwrite.h"
23
#include "avformat.h"
24
#include "ffm.h"
25
#if CONFIG_FFSERVER
26
#include <unistd.h>
27

    
28
int64_t ffm_read_write_index(int fd)
29
{
30
    uint8_t buf[8];
31

    
32
    lseek(fd, 8, SEEK_SET);
33
    if (read(fd, buf, 8) != 8)
34
        return AVERROR(EIO);
35
    return AV_RB64(buf);
36
}
37

    
38
int ffm_write_write_index(int fd, int64_t pos)
39
{
40
    uint8_t buf[8];
41
    int i;
42

    
43
    for(i=0;i<8;i++)
44
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
45
    lseek(fd, 8, SEEK_SET);
46
    if (write(fd, buf, 8) != 8)
47
        return AVERROR(EIO);
48
    return 8;
49
}
50

    
51
void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
52
{
53
    FFMContext *ffm = s->priv_data;
54
    ffm->write_index = pos;
55
    ffm->file_size = file_size;
56
}
57
#endif // CONFIG_FFSERVER
58

    
59
static int ffm_is_avail_data(AVFormatContext *s, int size)
60
{
61
    FFMContext *ffm = s->priv_data;
62
    int64_t pos, avail_size;
63
    int len;
64

    
65
    len = ffm->packet_end - ffm->packet_ptr;
66
    if (size <= len)
67
        return 1;
68
    pos = url_ftell(s->pb);
69
    if (!ffm->write_index) {
70
        if (pos == ffm->file_size)
71
            return AVERROR_EOF;
72
        avail_size = ffm->file_size - pos;
73
    } else {
74
    if (pos == ffm->write_index) {
75
        /* exactly at the end of stream */
76
        return AVERROR(EAGAIN);
77
    } else if (pos < ffm->write_index) {
78
        avail_size = ffm->write_index - pos;
79
    } else {
80
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
81
    }
82
    }
83
    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
84
    if (size <= avail_size)
85
        return 1;
86
    else
87
        return AVERROR(EAGAIN);
88
}
89

    
90
static int ffm_resync(AVFormatContext *s, int state)
91
{
92
    av_log(s, AV_LOG_ERROR, "resyncing\n");
93
    while (state != PACKET_ID) {
94
        if (url_feof(s->pb)) {
95
            av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
96
            return -1;
97
        }
98
        state = (state << 8) | get_byte(s->pb);
99
    }
100
    return 0;
101
}
102

    
103
/* first is true if we read the frame header */
104
static int ffm_read_data(AVFormatContext *s,
105
                         uint8_t *buf, int size, int header)
106
{
107
    FFMContext *ffm = s->priv_data;
108
    ByteIOContext *pb = s->pb;
109
    int len, fill_size, size1, frame_offset, id;
110

    
111
    size1 = size;
112
    while (size > 0) {
113
    redo:
114
        len = ffm->packet_end - ffm->packet_ptr;
115
        if (len < 0)
116
            return -1;
117
        if (len > size)
118
            len = size;
119
        if (len == 0) {
120
            if (url_ftell(pb) == ffm->file_size)
121
                url_fseek(pb, ffm->packet_size, SEEK_SET);
122
    retry_read:
123
            id = get_be16(pb); /* PACKET_ID */
124
            if (id != PACKET_ID)
125
                if (ffm_resync(s, id) < 0)
126
                    return -1;
127
            fill_size = get_be16(pb);
128
            ffm->dts = get_be64(pb);
129
            frame_offset = get_be16(pb);
130
            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
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            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
132
            if (ffm->packet_end < ffm->packet || frame_offset < 0)
133
                return -1;
134
            /* if first packet or resynchronization packet, we must
135
               handle it specifically */
136
            if (ffm->first_packet || (frame_offset & 0x8000)) {
137
                if (!frame_offset) {
138
                    /* This packet has no frame headers in it */
139
                    if (url_ftell(pb) >= ffm->packet_size * 3) {
140
                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
141
                        goto retry_read;
142
                    }
143
                    /* This is bad, we cannot find a valid frame header */
144
                    return 0;
145
                }
146
                ffm->first_packet = 0;
147
                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
148
                    return -1;
149
                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
150
                if (!header)
151
                    break;
152
            } else {
153
                ffm->packet_ptr = ffm->packet;
154
            }
155
            goto redo;
156
        }
157
        memcpy(buf, ffm->packet_ptr, len);
158
        buf += len;
159
        ffm->packet_ptr += len;
160
        size -= len;
161
        header = 0;
162
    }
163
    return size1 - size;
164
}
165

    
166
//#define DEBUG_SEEK
167

    
168
/* ensure that acutal seeking happens between FFM_PACKET_SIZE
169
   and file_size - FFM_PACKET_SIZE */
170
static void ffm_seek1(AVFormatContext *s, int64_t pos1)
171
{
172
    FFMContext *ffm = s->priv_data;
173
    ByteIOContext *pb = s->pb;
174
    int64_t pos;
175

    
176
    pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
177
    pos = FFMAX(pos, FFM_PACKET_SIZE);
178
#ifdef DEBUG_SEEK
179
    av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
180
#endif
181
    url_fseek(pb, pos, SEEK_SET);
182
}
183

    
184
static int64_t get_dts(AVFormatContext *s, int64_t pos)
185
{
186
    ByteIOContext *pb = s->pb;
187
    int64_t dts;
188

    
189
    ffm_seek1(s, pos);
190
    url_fskip(pb, 4);
191
    dts = get_be64(pb);
192
#ifdef DEBUG_SEEK
193
    av_log(s, AV_LOG_DEBUG, "dts=%0.6f\n", dts / 1000000.0);
194
#endif
195
    return dts;
196
}
197

    
198
static void adjust_write_index(AVFormatContext *s)
199
{
200
    FFMContext *ffm = s->priv_data;
201
    ByteIOContext *pb = s->pb;
202
    int64_t pts;
203
    //int64_t orig_write_index = ffm->write_index;
204
    int64_t pos_min, pos_max;
205
    int64_t pts_start;
206
    int64_t ptr = url_ftell(pb);
207

    
208

    
209
    pos_min = 0;
210
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
211

    
212
    pts_start = get_dts(s, pos_min);
213

    
214
    pts = get_dts(s, pos_max);
215

    
216
    if (pts - 100000 > pts_start)
217
        goto end;
218

    
219
    ffm->write_index = FFM_PACKET_SIZE;
220

    
221
    pts_start = get_dts(s, pos_min);
222

    
223
    pts = get_dts(s, pos_max);
224

    
225
    if (pts - 100000 <= pts_start) {
226
        while (1) {
227
            int64_t newpos;
228
            int64_t newpts;
229

    
230
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
231

    
232
            if (newpos == pos_min)
233
                break;
234

    
235
            newpts = get_dts(s, newpos);
236

    
237
            if (newpts - 100000 <= pts) {
238
                pos_max = newpos;
239
                pts = newpts;
240
            } else {
241
                pos_min = newpos;
242
            }
243
        }
244
        ffm->write_index += pos_max;
245
    }
246

    
247
    //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
248
    //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
249

    
250
 end:
251
    url_fseek(pb, ptr, SEEK_SET);
252
}
253

    
254

    
255
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
256
{
257
    FFMContext *ffm = s->priv_data;
258
    AVStream *st;
259
    ByteIOContext *pb = s->pb;
260
    AVCodecContext *codec;
261
    int i, nb_streams;
262
    uint32_t tag;
263

    
264
    /* header */
265
    tag = get_le32(pb);
266
    if (tag != MKTAG('F', 'F', 'M', '1'))
267
        goto fail;
268
    ffm->packet_size = get_be32(pb);
269
    if (ffm->packet_size != FFM_PACKET_SIZE)
270
        goto fail;
271
    ffm->write_index = get_be64(pb);
272
    /* get also filesize */
273
    if (!url_is_streamed(pb)) {
274
        ffm->file_size = url_fsize(pb);
275
        if (ffm->write_index)
276
            adjust_write_index(s);
277
    } else {
278
        ffm->file_size = (UINT64_C(1) << 63) - 1;
279
    }
280

    
281
    nb_streams = get_be32(pb);
282
    get_be32(pb); /* total bitrate */
283
    /* read each stream */
284
    for(i=0;i<nb_streams;i++) {
285
        char rc_eq_buf[128];
286

    
287
        st = av_new_stream(s, 0);
288
        if (!st)
289
            goto fail;
290

    
291
        av_set_pts_info(st, 64, 1, 1000000);
292

    
293
        codec = st->codec;
294
        /* generic info */
295
        codec->codec_id = get_be32(pb);
296
        codec->codec_type = get_byte(pb); /* codec_type */
297
        codec->bit_rate = get_be32(pb);
298
        st->quality = get_be32(pb);
299
        codec->flags = get_be32(pb);
300
        codec->flags2 = get_be32(pb);
301
        codec->debug = get_be32(pb);
302
        /* specific info */
303
        switch(codec->codec_type) {
304
        case CODEC_TYPE_VIDEO:
305
            codec->time_base.num = get_be32(pb);
306
            codec->time_base.den = get_be32(pb);
307
            codec->width = get_be16(pb);
308
            codec->height = get_be16(pb);
309
            codec->gop_size = get_be16(pb);
310
            codec->pix_fmt = get_be32(pb);
311
            codec->qmin = get_byte(pb);
312
            codec->qmax = get_byte(pb);
313
            codec->max_qdiff = get_byte(pb);
314
            codec->qcompress = get_be16(pb) / 10000.0;
315
            codec->qblur = get_be16(pb) / 10000.0;
316
            codec->bit_rate_tolerance = get_be32(pb);
317
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
318
            codec->rc_max_rate = get_be32(pb);
319
            codec->rc_min_rate = get_be32(pb);
320
            codec->rc_buffer_size = get_be32(pb);
321
            codec->i_quant_factor = av_int2dbl(get_be64(pb));
322
            codec->b_quant_factor = av_int2dbl(get_be64(pb));
323
            codec->i_quant_offset = av_int2dbl(get_be64(pb));
324
            codec->b_quant_offset = av_int2dbl(get_be64(pb));
325
            codec->dct_algo = get_be32(pb);
326
            codec->strict_std_compliance = get_be32(pb);
327
            codec->max_b_frames = get_be32(pb);
328
            codec->luma_elim_threshold = get_be32(pb);
329
            codec->chroma_elim_threshold = get_be32(pb);
330
            codec->mpeg_quant = get_be32(pb);
331
            codec->intra_dc_precision = get_be32(pb);
332
            codec->me_method = get_be32(pb);
333
            codec->mb_decision = get_be32(pb);
334
            codec->nsse_weight = get_be32(pb);
335
            codec->frame_skip_cmp = get_be32(pb);
336
            codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
337
            codec->codec_tag = get_be32(pb);
338
            codec->thread_count = get_byte(pb);
339
            codec->coder_type = get_be32(pb);
340
            codec->me_cmp = get_be32(pb);
341
            codec->partitions = get_be32(pb);
342
            codec->me_subpel_quality = get_be32(pb);
343
            codec->me_range = get_be32(pb);
344
            codec->keyint_min = get_be32(pb);
345
            codec->scenechange_threshold = get_be32(pb);
346
            codec->b_frame_strategy = get_be32(pb);
347
            codec->qcompress = av_int2dbl(get_be64(pb));
348
            codec->qblur = av_int2dbl(get_be64(pb));
349
            codec->max_qdiff = get_be32(pb);
350
            codec->refs = get_be32(pb);
351
            codec->directpred = get_be32(pb);
352
            break;
353
        case CODEC_TYPE_AUDIO:
354
            codec->sample_rate = get_be32(pb);
355
            codec->channels = get_le16(pb);
356
            codec->frame_size = get_le16(pb);
357
            break;
358
        default:
359
            goto fail;
360
        }
361
        if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
362
            codec->extradata_size = get_be32(pb);
363
            codec->extradata = av_malloc(codec->extradata_size);
364
            if (!codec->extradata)
365
                return AVERROR(ENOMEM);
366
            get_buffer(pb, codec->extradata, codec->extradata_size);
367
        }
368
    }
369

    
370
    /* get until end of block reached */
371
    while ((url_ftell(pb) % ffm->packet_size) != 0)
372
        get_byte(pb);
373

    
374
    /* init packet demux */
375
    ffm->packet_ptr = ffm->packet;
376
    ffm->packet_end = ffm->packet;
377
    ffm->frame_offset = 0;
378
    ffm->dts = 0;
379
    ffm->read_state = READ_HEADER;
380
    ffm->first_packet = 1;
381
    return 0;
382
 fail:
383
    for(i=0;i<s->nb_streams;i++) {
384
        st = s->streams[i];
385
        if (st) {
386
            av_free(st);
387
        }
388
    }
389
    return -1;
390
}
391

    
392
/* return < 0 if eof */
393
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
394
{
395
    int size;
396
    FFMContext *ffm = s->priv_data;
397
    int duration, ret;
398

    
399
    switch(ffm->read_state) {
400
    case READ_HEADER:
401
        if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
402
            return ret;
403

    
404
        dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
405
               url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
406
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
407
            FRAME_HEADER_SIZE)
408
            return -1;
409
        if (ffm->header[1] & FLAG_DTS)
410
            if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
411
                return -1;
412
#if 0
413
        av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
414
#endif
415
        ffm->read_state = READ_DATA;
416
        /* fall thru */
417
    case READ_DATA:
418
        size = AV_RB24(ffm->header + 2);
419
        if ((ret = ffm_is_avail_data(s, size)) < 0)
420
            return ret;
421

    
422
        duration = AV_RB24(ffm->header + 5);
423

    
424
        av_new_packet(pkt, size);
425
        pkt->stream_index = ffm->header[0];
426
        if ((unsigned)pkt->stream_index >= s->nb_streams) {
427
            av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
428
            av_free_packet(pkt);
429
            ffm->read_state = READ_HEADER;
430
            return -1;
431
        }
432
        pkt->pos = url_ftell(s->pb);
433
        if (ffm->header[1] & FLAG_KEY_FRAME)
434
            pkt->flags |= PKT_FLAG_KEY;
435

    
436
        ffm->read_state = READ_HEADER;
437
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
438
            /* bad case: desynchronized packet. we cancel all the packet loading */
439
            av_free_packet(pkt);
440
            return -1;
441
        }
442
        pkt->pts = AV_RB64(ffm->header+8);
443
        if (ffm->header[1] & FLAG_DTS)
444
            pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
445
        else
446
            pkt->dts = pkt->pts;
447
        pkt->duration = duration;
448
        break;
449
    }
450
    return 0;
451
}
452

    
453
/* seek to a given time in the file. The file read pointer is
454
   positioned at or before pts. XXX: the following code is quite
455
   approximative */
456
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
457
{
458
    FFMContext *ffm = s->priv_data;
459
    int64_t pos_min, pos_max, pos;
460
    int64_t pts_min, pts_max, pts;
461
    double pos1;
462

    
463
#ifdef DEBUG_SEEK
464
    av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
465
#endif
466
    /* find the position using linear interpolation (better than
467
       dichotomy in typical cases) */
468
    pos_min = FFM_PACKET_SIZE;
469
    pos_max = ffm->file_size - FFM_PACKET_SIZE;
470
    while (pos_min <= pos_max) {
471
        pts_min = get_dts(s, pos_min);
472
        pts_max = get_dts(s, pos_max);
473
        /* linear interpolation */
474
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
475
            (double)(pts_max - pts_min);
476
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
477
        if (pos <= pos_min)
478
            pos = pos_min;
479
        else if (pos >= pos_max)
480
            pos = pos_max;
481
        pts = get_dts(s, pos);
482
        /* check if we are lucky */
483
        if (pts == wanted_pts) {
484
            goto found;
485
        } else if (pts > wanted_pts) {
486
            pos_max = pos - FFM_PACKET_SIZE;
487
        } else {
488
            pos_min = pos + FFM_PACKET_SIZE;
489
        }
490
    }
491
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
492

    
493
 found:
494
    ffm_seek1(s, pos);
495

    
496
    /* reset read state */
497
    ffm->read_state = READ_HEADER;
498
    ffm->packet_ptr = ffm->packet;
499
    ffm->packet_end = ffm->packet;
500
    ffm->first_packet = 1;
501

    
502
    return 0;
503
}
504

    
505
static int ffm_probe(AVProbeData *p)
506
{
507
    if (
508
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
509
        p->buf[3] == '1')
510
        return AVPROBE_SCORE_MAX + 1;
511
    return 0;
512
}
513

    
514
AVInputFormat ffm_demuxer = {
515
    "ffm",
516
    NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
517
    sizeof(FFMContext),
518
    ffm_probe,
519
    ffm_read_header,
520
    ffm_read_packet,
521
    NULL,
522
    ffm_seek,
523
};