Statistics
| Branch: | Revision:

ffmpeg / libavformat / flvdec.c @ a0350330

History | View | Annotate | Download (19.5 KB)

1
/*
2
 * FLV demuxer
3
 * Copyright (c) 2003 The FFmpeg Project
4
 *
5
 * This demuxer will generate a 1 byte extradata for VP6F content.
6
 * It is composed of:
7
 *  - upper 4bits: difference between encoded width and visible width
8
 *  - lower 4bits: difference between encoded height and visible height
9
 *
10
 * This file is part of FFmpeg.
11
 *
12
 * FFmpeg is free software; you can redistribute it and/or
13
 * modify it under the terms of the GNU Lesser General Public
14
 * License as published by the Free Software Foundation; either
15
 * version 2.1 of the License, or (at your option) any later version.
16
 *
17
 * FFmpeg is distributed in the hope that it will be useful,
18
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20
 * Lesser General Public License for more details.
21
 *
22
 * You should have received a copy of the GNU Lesser General Public
23
 * License along with FFmpeg; if not, write to the Free Software
24
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25
 */
26

    
27
#include "libavutil/avstring.h"
28
#include "libavcodec/bytestream.h"
29
#include "libavcodec/mpeg4audio.h"
30
#include "avformat.h"
31
#include "avio_internal.h"
32
#include "flv.h"
33

    
34
typedef struct {
35
    int wrong_dts; ///< wrong dts due to negative cts
36
} FLVContext;
37

    
38
static int flv_probe(AVProbeData *p)
39
{
40
    const uint8_t *d;
41

    
42
    d = p->buf;
43
    if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) {
44
        return AVPROBE_SCORE_MAX;
45
    }
46
    return 0;
47
}
48

    
49
static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
50
    AVCodecContext *acodec = astream->codec;
51
    switch(flv_codecid) {
52
        //no distinction between S16 and S8 PCM codec flags
53
        case FLV_CODECID_PCM:
54
            acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 :
55
#if HAVE_BIGENDIAN
56
                                CODEC_ID_PCM_S16BE;
57
#else
58
                                CODEC_ID_PCM_S16LE;
59
#endif
60
            break;
61
        case FLV_CODECID_PCM_LE:
62
            acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : CODEC_ID_PCM_S16LE; break;
63
        case FLV_CODECID_AAC  : acodec->codec_id = CODEC_ID_AAC;                                    break;
64
        case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
65
        case FLV_CODECID_SPEEX:
66
            acodec->codec_id = CODEC_ID_SPEEX;
67
            acodec->sample_rate = 16000;
68
            break;
69
        case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
70
        case FLV_CODECID_NELLYMOSER_8KHZ_MONO:
71
            acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
72
            acodec->codec_id = CODEC_ID_NELLYMOSER;
73
            break;
74
        case FLV_CODECID_NELLYMOSER_16KHZ_MONO:
75
            acodec->sample_rate = 16000;
76
            acodec->codec_id = CODEC_ID_NELLYMOSER;
77
            break;
78
        case FLV_CODECID_NELLYMOSER:
79
            acodec->codec_id = CODEC_ID_NELLYMOSER;
80
            break;
81
        default:
82
            av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
83
            acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
84
    }
85
}
86

    
87
static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
88
    AVCodecContext *vcodec = vstream->codec;
89
    switch(flv_codecid) {
90
        case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
91
        case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
92
        case FLV_CODECID_SCREEN2: vcodec->codec_id = CODEC_ID_FLASHSV2; break;
93
        case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
94
        case FLV_CODECID_VP6A  :
95
            if(flv_codecid == FLV_CODECID_VP6A)
96
                vcodec->codec_id = CODEC_ID_VP6A;
97
            if(vcodec->extradata_size != 1) {
98
                vcodec->extradata_size = 1;
99
                vcodec->extradata = av_malloc(1);
100
            }
101
            vcodec->extradata[0] = avio_r8(s->pb);
102
            return 1; // 1 byte body size adjustment for flv_read_packet()
103
        case FLV_CODECID_H264:
104
            vcodec->codec_id = CODEC_ID_H264;
105
            return 3; // not 4, reading packet type will consume one byte
106
        default:
107
            av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
108
            vcodec->codec_tag = flv_codecid;
109
    }
110

    
111
    return 0;
112
}
113

    
114
static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
115
    int length = avio_rb16(ioc);
116
    if(length >= buffsize) {
117
        avio_skip(ioc, length);
118
        return -1;
119
    }
120

    
121
    avio_read(ioc, buffer, length);
122

    
123
    buffer[length] = '\0';
124

    
125
    return length;
126
}
127

    
128
static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
129
    unsigned int timeslen = 0, fileposlen = 0, i;
130
    char str_val[256];
131
    int64_t *times = NULL;
132
    int64_t *filepositions = NULL;
133
    int ret = 0;
134

    
135
    while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
136
        int64_t** current_array;
137
        unsigned int arraylen;
138

    
139
        // Expect array object in context
140
        if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
141
            break;
142

    
143
        arraylen = avio_rb32(ioc);
144
        if(arraylen>>28)
145
            break;
146

    
147
        if       (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
148
            current_array= &times;
149
            timeslen= arraylen;
150
        }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
151
            current_array= &filepositions;
152
            fileposlen= arraylen;
153
        }else // unexpected metatag inside keyframes, will not use such metadata for indexing
154
            break;
155

    
156
        if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
157
            ret = AVERROR(ENOMEM);
158
            goto finish;
159
        }
160

    
161
        for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
162
            if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
163
                goto finish;
164
            current_array[0][i] = av_int2dbl(avio_rb64(ioc));
165
        }
166
    }
167

    
168
    if (timeslen == fileposlen) {
169
         for(i = 0; i < timeslen; i++)
170
             av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
171
    } else
172
        av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
173

    
174
finish:
175
    av_freep(&times);
176
    av_freep(&filepositions);
177
    avio_seek(ioc, max_pos, SEEK_SET);
178
    return ret;
179
}
180

    
181
static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
182
    AVCodecContext *acodec, *vcodec;
183
    AVIOContext *ioc;
184
    AMFDataType amf_type;
185
    char str_val[256];
186
    double num_val;
187

    
188
    num_val = 0;
189
    ioc = s->pb;
190

    
191
    amf_type = avio_r8(ioc);
192

    
193
    switch(amf_type) {
194
        case AMF_DATA_TYPE_NUMBER:
195
            num_val = av_int2dbl(avio_rb64(ioc)); break;
196
        case AMF_DATA_TYPE_BOOL:
197
            num_val = avio_r8(ioc); break;
198
        case AMF_DATA_TYPE_STRING:
199
            if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
200
                return -1;
201
            break;
202
        case AMF_DATA_TYPE_OBJECT: {
203
            unsigned int keylen;
204

    
205
            if (!strcmp(KEYFRAMES_TAG, key) && depth == 1)
206
                if (parse_keyframes_index(s, ioc, vstream, max_pos) < 0)
207
                    return -1;
208

    
209
            while(avio_tell(ioc) < max_pos - 2 && (keylen = avio_rb16(ioc))) {
210
                avio_skip(ioc, keylen); //skip key string
211
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
212
                    return -1; //if we couldn't skip, bomb out.
213
            }
214
            if(avio_r8(ioc) != AMF_END_OF_OBJECT)
215
                return -1;
216
        }
217
            break;
218
        case AMF_DATA_TYPE_NULL:
219
        case AMF_DATA_TYPE_UNDEFINED:
220
        case AMF_DATA_TYPE_UNSUPPORTED:
221
            break; //these take up no additional space
222
        case AMF_DATA_TYPE_MIXEDARRAY:
223
            avio_skip(ioc, 4); //skip 32-bit max array index
224
            while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
225
                //this is the only case in which we would want a nested parse to not skip over the object
226
                if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
227
                    return -1;
228
            }
229
            if(avio_r8(ioc) != AMF_END_OF_OBJECT)
230
                return -1;
231
            break;
232
        case AMF_DATA_TYPE_ARRAY: {
233
            unsigned int arraylen, i;
234

    
235
            arraylen = avio_rb32(ioc);
236
            for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
237
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
238
                    return -1; //if we couldn't skip, bomb out.
239
            }
240
        }
241
            break;
242
        case AMF_DATA_TYPE_DATE:
243
            avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
244
            break;
245
        default: //unsupported type, we couldn't skip
246
            return -1;
247
    }
248

    
249
    if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
250
        acodec = astream ? astream->codec : NULL;
251
        vcodec = vstream ? vstream->codec : NULL;
252

    
253
        if(amf_type == AMF_DATA_TYPE_BOOL) {
254
            av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
255
            av_metadata_set2(&s->metadata, key, str_val, 0);
256
        } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
257
            snprintf(str_val, sizeof(str_val), "%.f", num_val);
258
            av_metadata_set2(&s->metadata, key, str_val, 0);
259
            if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
260
            else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
261
                vcodec->bit_rate = num_val * 1024.0;
262
            else if(!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
263
                acodec->bit_rate = num_val * 1024.0;
264
        } else if (amf_type == AMF_DATA_TYPE_STRING)
265
            av_metadata_set2(&s->metadata, key, str_val, 0);
266
    }
267

    
268
    return 0;
269
}
270

    
271
static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
272
    AMFDataType type;
273
    AVStream *stream, *astream, *vstream;
274
    AVIOContext *ioc;
275
    int i;
276
    char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
277

    
278
    astream = NULL;
279
    vstream = NULL;
280
    ioc = s->pb;
281

    
282
    //first object needs to be "onMetaData" string
283
    type = avio_r8(ioc);
284
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
285
        return -1;
286

    
287
    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
288
    for(i = 0; i < s->nb_streams; i++) {
289
        stream = s->streams[i];
290
        if     (stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
291
        else if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
292
    }
293

    
294
    //parse the second object (we want a mixed array)
295
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
296
        return -1;
297

    
298
    return 0;
299
}
300

    
301
static AVStream *create_stream(AVFormatContext *s, int is_audio){
302
    AVStream *st = av_new_stream(s, is_audio);
303
    if (!st)
304
        return NULL;
305
    st->codec->codec_type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
306
    av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
307
    return st;
308
}
309

    
310
static int flv_read_header(AVFormatContext *s,
311
                           AVFormatParameters *ap)
312
{
313
    int offset, flags;
314

    
315
    avio_skip(s->pb, 4);
316
    flags = avio_r8(s->pb);
317
    /* old flvtool cleared this field */
318
    /* FIXME: better fix needed */
319
    if (!flags) {
320
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
321
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
322
    }
323

    
324
    if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
325
             != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
326
        s->ctx_flags |= AVFMTCTX_NOHEADER;
327

    
328
    if(flags & FLV_HEADER_FLAG_HASVIDEO){
329
        if(!create_stream(s, 0))
330
            return AVERROR(ENOMEM);
331
    }
332
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
333
        if(!create_stream(s, 1))
334
            return AVERROR(ENOMEM);
335
    }
336

    
337
    offset = avio_rb32(s->pb);
338
    avio_seek(s->pb, offset, SEEK_SET);
339
    avio_skip(s->pb, 4);
340

    
341
    s->start_time = 0;
342

    
343
    return 0;
344
}
345

    
346
static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
347
{
348
    av_free(st->codec->extradata);
349
    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
350
    if (!st->codec->extradata)
351
        return AVERROR(ENOMEM);
352
    st->codec->extradata_size = size;
353
    avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
354
    return 0;
355
}
356

    
357
static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
358
{
359
    FLVContext *flv = s->priv_data;
360
    int ret, i, type, size, flags, is_audio;
361
    int64_t next, pos;
362
    int64_t dts, pts = AV_NOPTS_VALUE;
363
    AVStream *st = NULL;
364

    
365
 for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
366
    pos = avio_tell(s->pb);
367
    type = avio_r8(s->pb);
368
    size = avio_rb24(s->pb);
369
    dts = avio_rb24(s->pb);
370
    dts |= avio_r8(s->pb) << 24;
371
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts);
372
    if (url_feof(s->pb))
373
        return AVERROR_EOF;
374
    avio_skip(s->pb, 3); /* stream id, always 0 */
375
    flags = 0;
376

    
377
    if(size == 0)
378
        continue;
379

    
380
    next= size + avio_tell(s->pb);
381

    
382
    if (type == FLV_TAG_TYPE_AUDIO) {
383
        is_audio=1;
384
        flags = avio_r8(s->pb);
385
        size--;
386
    } else if (type == FLV_TAG_TYPE_VIDEO) {
387
        is_audio=0;
388
        flags = avio_r8(s->pb);
389
        size--;
390
        if ((flags & 0xf0) == 0x50) /* video info / command frame */
391
            goto skip;
392
    } else {
393
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
394
            flv_read_metabody(s, next);
395
        else /* skip packet */
396
            av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
397
    skip:
398
        avio_seek(s->pb, next, SEEK_SET);
399
        continue;
400
    }
401

    
402
    /* skip empty data packets */
403
    if (!size)
404
        continue;
405

    
406
    /* now find stream */
407
    for(i=0;i<s->nb_streams;i++) {
408
        st = s->streams[i];
409
        if (st->id == is_audio)
410
            break;
411
    }
412
    if(i == s->nb_streams){
413
        av_log(s, AV_LOG_ERROR, "invalid stream\n");
414
        st= create_stream(s, is_audio);
415
        s->ctx_flags &= ~AVFMTCTX_NOHEADER;
416
    }
417
//    av_log(s, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
418
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
419
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
420
       || st->discard >= AVDISCARD_ALL
421
       ){
422
        avio_seek(s->pb, next, SEEK_SET);
423
        continue;
424
    }
425
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
426
        av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
427
    break;
428
 }
429

    
430
    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
431
    if(!url_is_streamed(s->pb) && (!s->duration || s->duration==AV_NOPTS_VALUE)){
432
        int size;
433
        const int64_t pos= avio_tell(s->pb);
434
        const int64_t fsize= avio_size(s->pb);
435
        avio_seek(s->pb, fsize-4, SEEK_SET);
436
        size= avio_rb32(s->pb);
437
        avio_seek(s->pb, fsize-3-size, SEEK_SET);
438
        if(size == avio_rb24(s->pb) + 11){
439
            uint32_t ts = avio_rb24(s->pb);
440
            ts |= avio_r8(s->pb) << 24;
441
            s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
442
        }
443
        avio_seek(s->pb, pos, SEEK_SET);
444
    }
445

    
446
    if(is_audio){
447
        if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
448
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
449
            st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
450
            st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
451
        }
452
        if(!st->codec->codec_id){
453
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
454
        }
455
    }else{
456
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
457
    }
458

    
459
    if (st->codec->codec_id == CODEC_ID_AAC ||
460
        st->codec->codec_id == CODEC_ID_H264) {
461
        int type = avio_r8(s->pb);
462
        size--;
463
        if (st->codec->codec_id == CODEC_ID_H264) {
464
            int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
465
            pts = dts + cts;
466
            if (cts < 0) { // dts are wrong
467
                flv->wrong_dts = 1;
468
                av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
469
            }
470
            if (flv->wrong_dts)
471
                dts = AV_NOPTS_VALUE;
472
        }
473
        if (type == 0) {
474
            if ((ret = flv_get_extradata(s, st, size)) < 0)
475
                return ret;
476
            if (st->codec->codec_id == CODEC_ID_AAC) {
477
                MPEG4AudioConfig cfg;
478
                ff_mpeg4audio_get_config(&cfg, st->codec->extradata,
479
                                         st->codec->extradata_size);
480
                st->codec->channels = cfg.channels;
481
                if (cfg.ext_sample_rate)
482
                    st->codec->sample_rate = cfg.ext_sample_rate;
483
                else
484
                    st->codec->sample_rate = cfg.sample_rate;
485
                av_dlog(s, "mp4a config channels %d sample rate %d\n",
486
                        st->codec->channels, st->codec->sample_rate);
487
            }
488

    
489
            ret = AVERROR(EAGAIN);
490
            goto leave;
491
        }
492
    }
493

    
494
    /* skip empty data packets */
495
    if (!size) {
496
        ret = AVERROR(EAGAIN);
497
        goto leave;
498
    }
499

    
500
    ret= av_get_packet(s->pb, pkt, size);
501
    if (ret < 0) {
502
        return AVERROR(EIO);
503
    }
504
    /* note: we need to modify the packet size here to handle the last
505
       packet */
506
    pkt->size = ret;
507
    pkt->dts = dts;
508
    pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
509
    pkt->stream_index = st->index;
510

    
511
    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
512
        pkt->flags |= AV_PKT_FLAG_KEY;
513

    
514
leave:
515
    avio_skip(s->pb, 4);
516
    return ret;
517
}
518

    
519
static int flv_read_seek(AVFormatContext *s, int stream_index,
520
    int64_t ts, int flags)
521
{
522
    return ffio_read_seek(s->pb, stream_index, ts, flags);
523
}
524

    
525
#if 0 /* don't know enough to implement this */
526
static int flv_read_seek2(AVFormatContext *s, int stream_index,
527
    int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
528
{
529
    int ret = AVERROR(ENOSYS);
530

531
    if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD;
532

533
    if (url_is_streamed(s->pb)) {
534
        if (stream_index < 0) {
535
            stream_index = av_find_default_stream_index(s);
536
            if (stream_index < 0)
537
                return -1;
538

539
            /* timestamp for default must be expressed in AV_TIME_BASE units */
540
            ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE,
541
                flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
542
        }
543
        ret = ffio_read_seek(s->pb, stream_index, ts, flags);
544
    }
545

546
    if (ret == AVERROR(ENOSYS))
547
        ret = av_seek_frame(s, stream_index, ts, flags);
548
    return ret;
549
}
550
#endif
551

    
552
AVInputFormat ff_flv_demuxer = {
553
    "flv",
554
    NULL_IF_CONFIG_SMALL("FLV format"),
555
    sizeof(FLVContext),
556
    flv_probe,
557
    flv_read_header,
558
    flv_read_packet,
559
    .read_seek = flv_read_seek,
560
#if 0
561
    .read_seek2 = flv_read_seek2,
562
#endif
563
    .extensions = "flv",
564
    .value = CODEC_ID_FLV1,
565
};