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ffmpeg / libavformat / ffmdec.c @ af274fd1

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1
/*
2
 * FFM (ffserver live feed) demuxer
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 * Copyright (c) 2001 Fabrice Bellard.
4
 *
5
 * This file is part of FFmpeg.
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 *
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.
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 *
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.
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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

    
22
#include "avformat.h"
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#include "ffm.h"
24
#ifdef CONFIG_FFSERVER
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#include <unistd.h>
26

    
27
offset_t ffm_read_write_index(int fd)
28
{
29
    uint8_t buf[8];
30

    
31
    lseek(fd, 8, SEEK_SET);
32
    read(fd, buf, 8);
33
    return AV_RB64(buf);
34
}
35

    
36
void ffm_write_write_index(int fd, offset_t pos)
37
{
38
    uint8_t buf[8];
39
    int i;
40

    
41
    for(i=0;i<8;i++)
42
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
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    lseek(fd, 8, SEEK_SET);
44
    write(fd, buf, 8);
45
}
46

    
47
void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
48
{
49
    FFMContext *ffm = s->priv_data;
50
    ffm->write_index = pos;
51
    ffm->file_size = file_size;
52
}
53
#endif // CONFIG_FFSERVER
54

    
55
static int ffm_is_avail_data(AVFormatContext *s, int size)
56
{
57
    FFMContext *ffm = s->priv_data;
58
    offset_t pos, avail_size;
59
    int len;
60

    
61
    len = ffm->packet_end - ffm->packet_ptr;
62
    if (size <= len)
63
        return 1;
64
    pos = url_ftell(s->pb);
65
    if (pos == ffm->write_index) {
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        /* exactly at the end of stream */
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        return 0;
68
    } else if (pos < ffm->write_index) {
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        avail_size = ffm->write_index - pos;
70
    } else {
71
        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
72
    }
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    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
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    if (size <= avail_size)
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        return 1;
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    else
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        return 0;
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}
79

    
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/* first is true if we read the frame header */
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static int ffm_read_data(AVFormatContext *s,
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                         uint8_t *buf, int size, int header)
83
{
84
    FFMContext *ffm = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int len, fill_size, size1, frame_offset;
87

    
88
    size1 = size;
89
    while (size > 0) {
90
    redo:
91
        len = ffm->packet_end - ffm->packet_ptr;
92
        if (len < 0)
93
            return -1;
94
        if (len > size)
95
            len = size;
96
        if (len == 0) {
97
            if (url_ftell(pb) == ffm->file_size)
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                url_fseek(pb, ffm->packet_size, SEEK_SET);
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    retry_read:
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            get_be16(pb); /* PACKET_ID */
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            fill_size = get_be16(pb);
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            ffm->dts = get_be64(pb);
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            frame_offset = get_be16(pb);
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            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);
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            if (ffm->packet_end < ffm->packet || frame_offset < 0)
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                return -1;
108
            /* if first packet or resynchronization packet, we must
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               handle it specifically */
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            if (ffm->first_packet || (frame_offset & 0x8000)) {
111
                if (!frame_offset) {
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                    /* This packet has no frame headers in it */
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                    if (url_ftell(pb) >= ffm->packet_size * 3) {
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                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
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                        goto retry_read;
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                    }
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                    /* This is bad, we cannot find a valid frame header */
118
                    return 0;
119
                }
120
                ffm->first_packet = 0;
121
                if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
122
                    return -1;
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                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
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                if (!header)
125
                    break;
126
            } else {
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                ffm->packet_ptr = ffm->packet;
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            }
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            goto redo;
130
        }
131
        memcpy(buf, ffm->packet_ptr, len);
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        buf += len;
133
        ffm->packet_ptr += len;
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        size -= len;
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        header = 0;
136
    }
137
    return size1 - size;
138
}
139

    
140
//#define DEBUG_SEEK
141

    
142
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
143
   by the write position inside this function */
144
static void ffm_seek1(AVFormatContext *s, offset_t pos1)
145
{
146
    FFMContext *ffm = s->priv_data;
147
    ByteIOContext *pb = s->pb;
148
    offset_t pos;
149

    
150
    pos = pos1 + ffm->write_index;
151
    if (pos >= ffm->file_size)
152
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
153
#ifdef DEBUG_SEEK
154
    av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
155
#endif
156
    url_fseek(pb, pos, SEEK_SET);
157
}
158

    
159
static int64_t get_dts(AVFormatContext *s, offset_t pos)
160
{
161
    ByteIOContext *pb = s->pb;
162
    int64_t dts;
163

    
164
    ffm_seek1(s, pos);
165
    url_fskip(pb, 4);
166
    dts = get_be64(pb);
167
#ifdef DEBUG_SEEK
168
    av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
169
#endif
170
    return dts;
171
}
172

    
173
static void adjust_write_index(AVFormatContext *s)
174
{
175
    FFMContext *ffm = s->priv_data;
176
    ByteIOContext *pb = s->pb;
177
    int64_t pts;
178
    //offset_t orig_write_index = ffm->write_index;
179
    offset_t pos_min, pos_max;
180
    int64_t pts_start;
181
    offset_t ptr = url_ftell(pb);
182

    
183

    
184
    pos_min = 0;
185
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
186

    
187
    pts_start = get_dts(s, pos_min);
188

    
189
    pts = get_dts(s, pos_max);
190

    
191
    if (pts - 100000 > pts_start)
192
        goto end;
193

    
194
    ffm->write_index = FFM_PACKET_SIZE;
195

    
196
    pts_start = get_dts(s, pos_min);
197

    
198
    pts = get_dts(s, pos_max);
199

    
200
    if (pts - 100000 <= pts_start) {
201
        while (1) {
202
            offset_t newpos;
203
            int64_t newpts;
204

    
205
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
206

    
207
            if (newpos == pos_min)
208
                break;
209

    
210
            newpts = get_dts(s, newpos);
211

    
212
            if (newpts - 100000 <= pts) {
213
                pos_max = newpos;
214
                pts = newpts;
215
            } else {
216
                pos_min = newpos;
217
            }
218
        }
219
        ffm->write_index += pos_max;
220
    }
221

    
222
    //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
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    //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
224

    
225
 end:
226
    url_fseek(pb, ptr, SEEK_SET);
227
}
228

    
229

    
230
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
231
{
232
    FFMContext *ffm = s->priv_data;
233
    AVStream *st;
234
    ByteIOContext *pb = s->pb;
235
    AVCodecContext *codec;
236
    int i, nb_streams;
237
    uint32_t tag;
238

    
239
    /* header */
240
    tag = get_le32(pb);
241
    if (tag != MKTAG('F', 'F', 'M', '1'))
242
        goto fail;
243
    ffm->packet_size = get_be32(pb);
244
    if (ffm->packet_size != FFM_PACKET_SIZE)
245
        goto fail;
246
    ffm->write_index = get_be64(pb);
247
    /* get also filesize */
248
    if (!url_is_streamed(pb)) {
249
        ffm->file_size = url_fsize(pb);
250
        adjust_write_index(s);
251
    } else {
252
        ffm->file_size = (UINT64_C(1) << 63) - 1;
253
    }
254

    
255
    nb_streams = get_be32(pb);
256
    get_be32(pb); /* total bitrate */
257
    /* read each stream */
258
    for(i=0;i<nb_streams;i++) {
259
        char rc_eq_buf[128];
260

    
261
        st = av_new_stream(s, 0);
262
        if (!st)
263
            goto fail;
264
        s->streams[i] = st;
265

    
266
        av_set_pts_info(st, 64, 1, 1000000);
267

    
268
        codec = st->codec;
269
        /* generic info */
270
        codec->codec_id = get_be32(pb);
271
        codec->codec_type = get_byte(pb); /* codec_type */
272
        codec->bit_rate = get_be32(pb);
273
        st->quality = get_be32(pb);
274
        codec->flags = get_be32(pb);
275
        codec->flags2 = get_be32(pb);
276
        codec->debug = get_be32(pb);
277
        /* specific info */
278
        switch(codec->codec_type) {
279
        case CODEC_TYPE_VIDEO:
280
            codec->time_base.num = get_be32(pb);
281
            codec->time_base.den = get_be32(pb);
282
            codec->width = get_be16(pb);
283
            codec->height = get_be16(pb);
284
            codec->gop_size = get_be16(pb);
285
            codec->pix_fmt = get_be32(pb);
286
            codec->qmin = get_byte(pb);
287
            codec->qmax = get_byte(pb);
288
            codec->max_qdiff = get_byte(pb);
289
            codec->qcompress = get_be16(pb) / 10000.0;
290
            codec->qblur = get_be16(pb) / 10000.0;
291
            codec->bit_rate_tolerance = get_be32(pb);
292
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
293
            codec->rc_max_rate = get_be32(pb);
294
            codec->rc_min_rate = get_be32(pb);
295
            codec->rc_buffer_size = get_be32(pb);
296
            codec->i_quant_factor = av_int2dbl(get_be64(pb));
297
            codec->b_quant_factor = av_int2dbl(get_be64(pb));
298
            codec->i_quant_offset = av_int2dbl(get_be64(pb));
299
            codec->b_quant_offset = av_int2dbl(get_be64(pb));
300
            codec->dct_algo = get_be32(pb);
301
            codec->strict_std_compliance = get_be32(pb);
302
            codec->max_b_frames = get_be32(pb);
303
            codec->luma_elim_threshold = get_be32(pb);
304
            codec->chroma_elim_threshold = get_be32(pb);
305
            codec->mpeg_quant = get_be32(pb);
306
            codec->intra_dc_precision = get_be32(pb);
307
            codec->me_method = get_be32(pb);
308
            codec->mb_decision = get_be32(pb);
309
            codec->nsse_weight = get_be32(pb);
310
            codec->frame_skip_cmp = get_be32(pb);
311
            codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
312
            codec->codec_tag = get_be32(pb);
313
            codec->thread_count = get_byte(pb);
314
            break;
315
        case CODEC_TYPE_AUDIO:
316
            codec->sample_rate = get_be32(pb);
317
            codec->channels = get_le16(pb);
318
            codec->frame_size = get_le16(pb);
319
            break;
320
        default:
321
            goto fail;
322
        }
323
        if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
324
            codec->extradata_size = get_be32(pb);
325
            codec->extradata = av_malloc(codec->extradata_size);
326
            if (!codec->extradata)
327
                return AVERROR(ENOMEM);
328
            get_buffer(pb, codec->extradata, codec->extradata_size);
329
        }
330
    }
331

    
332
    /* get until end of block reached */
333
    while ((url_ftell(pb) % ffm->packet_size) != 0)
334
        get_byte(pb);
335

    
336
    /* init packet demux */
337
    ffm->packet_ptr = ffm->packet;
338
    ffm->packet_end = ffm->packet;
339
    ffm->frame_offset = 0;
340
    ffm->dts = 0;
341
    ffm->read_state = READ_HEADER;
342
    ffm->first_packet = 1;
343
    return 0;
344
 fail:
345
    for(i=0;i<s->nb_streams;i++) {
346
        st = s->streams[i];
347
        if (st) {
348
            av_free(st);
349
        }
350
    }
351
    return -1;
352
}
353

    
354
/* return < 0 if eof */
355
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
356
{
357
    int size;
358
    FFMContext *ffm = s->priv_data;
359
    int duration;
360

    
361
    switch(ffm->read_state) {
362
    case READ_HEADER:
363
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) {
364
            return AVERROR(EAGAIN);
365
        }
366
        dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
367
               url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
368
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
369
            FRAME_HEADER_SIZE)
370
            return AVERROR(EAGAIN);
371
        if (ffm->header[1] & FLAG_DTS)
372
            if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
373
                return AVERROR(EAGAIN);
374
#if 0
375
        av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
376
#endif
377
        ffm->read_state = READ_DATA;
378
        /* fall thru */
379
    case READ_DATA:
380
        size = AV_RB24(ffm->header + 2);
381
        if (!ffm_is_avail_data(s, size)) {
382
            return AVERROR(EAGAIN);
383
        }
384

    
385
        duration = AV_RB24(ffm->header + 5);
386

    
387
        av_new_packet(pkt, size);
388
        pkt->stream_index = ffm->header[0];
389
        if ((unsigned)pkt->stream_index >= s->nb_streams) {
390
            av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
391
            av_free_packet(pkt);
392
            ffm->read_state = READ_HEADER;
393
            return AVERROR(EAGAIN);
394
        }
395
        pkt->pos = url_ftell(s->pb);
396
        if (ffm->header[1] & FLAG_KEY_FRAME)
397
            pkt->flags |= PKT_FLAG_KEY;
398

    
399
        ffm->read_state = READ_HEADER;
400
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
401
            /* bad case: desynchronized packet. we cancel all the packet loading */
402
            av_free_packet(pkt);
403
            return AVERROR(EAGAIN);
404
        }
405
        pkt->pts = AV_RB64(ffm->header+8);
406
        if (ffm->header[1] & FLAG_DTS)
407
            pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
408
        else
409
            pkt->dts = pkt->pts;
410
        pkt->duration = duration;
411
        break;
412
    }
413
    return 0;
414
}
415

    
416
/* seek to a given time in the file. The file read pointer is
417
   positioned at or before pts. XXX: the following code is quite
418
   approximative */
419
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
420
{
421
    FFMContext *ffm = s->priv_data;
422
    offset_t pos_min, pos_max, pos;
423
    int64_t pts_min, pts_max, pts;
424
    double pos1;
425

    
426
#ifdef DEBUG_SEEK
427
    av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
428
#endif
429
    /* find the position using linear interpolation (better than
430
       dichotomy in typical cases) */
431
    pos_min = 0;
432
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
433
    while (pos_min <= pos_max) {
434
        pts_min = get_dts(s, pos_min);
435
        pts_max = get_dts(s, pos_max);
436
        /* linear interpolation */
437
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
438
            (double)(pts_max - pts_min);
439
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
440
        if (pos <= pos_min)
441
            pos = pos_min;
442
        else if (pos >= pos_max)
443
            pos = pos_max;
444
        pts = get_dts(s, pos);
445
        /* check if we are lucky */
446
        if (pts == wanted_pts) {
447
            goto found;
448
        } else if (pts > wanted_pts) {
449
            pos_max = pos - FFM_PACKET_SIZE;
450
        } else {
451
            pos_min = pos + FFM_PACKET_SIZE;
452
        }
453
    }
454
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
455
    if (pos > 0)
456
        pos -= FFM_PACKET_SIZE;
457
 found:
458
    ffm_seek1(s, pos);
459

    
460
    /* reset read state */
461
    ffm->read_state = READ_HEADER;
462
    ffm->packet_ptr = ffm->packet;
463
    ffm->packet_end = ffm->packet;
464
    ffm->first_packet = 1;
465

    
466
    return 0;
467
}
468

    
469
static int ffm_probe(AVProbeData *p)
470
{
471
    if (
472
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
473
        p->buf[3] == '1')
474
        return AVPROBE_SCORE_MAX + 1;
475
    return 0;
476
}
477

    
478
AVInputFormat ffm_demuxer = {
479
    "ffm",
480
    NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
481
    sizeof(FFMContext),
482
    ffm_probe,
483
    ffm_read_header,
484
    ffm_read_packet,
485
    NULL,
486
    ffm_seek,
487
};