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ffmpeg / libavformat / flvdec.c @ ba667e60

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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
    int64_t initial_pos = url_ftell(ioc);
135

    
136
    while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
137
        int64_t** current_array;
138
        unsigned int arraylen;
139

    
140
        // Expect array object in context
141
        if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
142
            break;
143

    
144
        arraylen = avio_rb32(ioc);
145
        if(arraylen>>28)
146
            break;
147

    
148
        if       (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
149
            current_array= &times;
150
            timeslen= arraylen;
151
        }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
152
            current_array= &filepositions;
153
            fileposlen= arraylen;
154
        }else // unexpected metatag inside keyframes, will not use such metadata for indexing
155
            break;
156

    
157
        if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
158
            ret = AVERROR(ENOMEM);
159
            goto finish;
160
        }
161

    
162
        for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
163
            if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
164
                goto finish;
165
            current_array[0][i] = av_int2dbl(avio_rb64(ioc));
166
        }
167
    }
168

    
169
    if (timeslen == fileposlen) {
170
         for(i = 0; i < timeslen; i++)
171
             av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
172
    } else
173
        av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
174

    
175
finish:
176
    av_freep(&times);
177
    av_freep(&filepositions);
178
    avio_seek(ioc, initial_pos, SEEK_SET);
179
    return ret;
180
}
181

    
182
static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
183
    AVCodecContext *acodec, *vcodec;
184
    AVIOContext *ioc;
185
    AMFDataType amf_type;
186
    char str_val[256];
187
    double num_val;
188

    
189
    num_val = 0;
190
    ioc = s->pb;
191

    
192
    amf_type = avio_r8(ioc);
193

    
194
    switch(amf_type) {
195
        case AMF_DATA_TYPE_NUMBER:
196
            num_val = av_int2dbl(avio_rb64(ioc)); break;
197
        case AMF_DATA_TYPE_BOOL:
198
            num_val = avio_r8(ioc); break;
199
        case AMF_DATA_TYPE_STRING:
200
            if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
201
                return -1;
202
            break;
203
        case AMF_DATA_TYPE_OBJECT: {
204
            unsigned int keylen;
205

    
206
            if (key && !strcmp(KEYFRAMES_TAG, key) && depth == 1)
207
                if (parse_keyframes_index(s, ioc, vstream, max_pos) < 0)
208
                    return -1;
209

    
210
            while(avio_tell(ioc) < max_pos - 2 && (keylen = avio_rb16(ioc))) {
211
                avio_skip(ioc, keylen); //skip key string
212
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
213
                    return -1; //if we couldn't skip, bomb out.
214
            }
215
            if(avio_r8(ioc) != AMF_END_OF_OBJECT)
216
                return -1;
217
        }
218
            break;
219
        case AMF_DATA_TYPE_NULL:
220
        case AMF_DATA_TYPE_UNDEFINED:
221
        case AMF_DATA_TYPE_UNSUPPORTED:
222
            break; //these take up no additional space
223
        case AMF_DATA_TYPE_MIXEDARRAY:
224
            avio_skip(ioc, 4); //skip 32-bit max array index
225
            while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
226
                //this is the only case in which we would want a nested parse to not skip over the object
227
                if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
228
                    return -1;
229
            }
230
            if(avio_r8(ioc) != AMF_END_OF_OBJECT)
231
                return -1;
232
            break;
233
        case AMF_DATA_TYPE_ARRAY: {
234
            unsigned int arraylen, i;
235

    
236
            arraylen = avio_rb32(ioc);
237
            for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
238
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
239
                    return -1; //if we couldn't skip, bomb out.
240
            }
241
        }
242
            break;
243
        case AMF_DATA_TYPE_DATE:
244
            avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
245
            break;
246
        default: //unsupported type, we couldn't skip
247
            return -1;
248
    }
249

    
250
    if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
251
        acodec = astream ? astream->codec : NULL;
252
        vcodec = vstream ? vstream->codec : NULL;
253

    
254
        if(amf_type == AMF_DATA_TYPE_BOOL) {
255
            av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
256
            av_metadata_set2(&s->metadata, key, str_val, 0);
257
        } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
258
            snprintf(str_val, sizeof(str_val), "%.f", num_val);
259
            av_metadata_set2(&s->metadata, key, str_val, 0);
260
            if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
261
            else if(!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
262
                vcodec->bit_rate = num_val * 1024.0;
263
            else if(!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
264
                acodec->bit_rate = num_val * 1024.0;
265
        } else if (amf_type == AMF_DATA_TYPE_STRING)
266
            av_metadata_set2(&s->metadata, key, str_val, 0);
267
    }
268

    
269
    return 0;
270
}
271

    
272
static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
273
    AMFDataType type;
274
    AVStream *stream, *astream, *vstream;
275
    AVIOContext *ioc;
276
    int i;
277
    char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
278

    
279
    astream = NULL;
280
    vstream = NULL;
281
    ioc = s->pb;
282

    
283
    //first object needs to be "onMetaData" string
284
    type = avio_r8(ioc);
285
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
286
        return -1;
287

    
288
    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
289
    for(i = 0; i < s->nb_streams; i++) {
290
        stream = s->streams[i];
291
        if     (stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
292
        else if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
293
    }
294

    
295
    //parse the second object (we want a mixed array)
296
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
297
        return -1;
298

    
299
    return 0;
300
}
301

    
302
static AVStream *create_stream(AVFormatContext *s, int is_audio){
303
    AVStream *st = av_new_stream(s, is_audio);
304
    if (!st)
305
        return NULL;
306
    st->codec->codec_type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
307
    av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
308
    return st;
309
}
310

    
311
static int flv_read_header(AVFormatContext *s,
312
                           AVFormatParameters *ap)
313
{
314
    int offset, flags;
315

    
316
    avio_skip(s->pb, 4);
317
    flags = avio_r8(s->pb);
318
    /* old flvtool cleared this field */
319
    /* FIXME: better fix needed */
320
    if (!flags) {
321
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
322
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
323
    }
324

    
325
    if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
326
             != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
327
        s->ctx_flags |= AVFMTCTX_NOHEADER;
328

    
329
    if(flags & FLV_HEADER_FLAG_HASVIDEO){
330
        if(!create_stream(s, 0))
331
            return AVERROR(ENOMEM);
332
    }
333
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
334
        if(!create_stream(s, 1))
335
            return AVERROR(ENOMEM);
336
    }
337

    
338
    offset = avio_rb32(s->pb);
339
    avio_seek(s->pb, offset, SEEK_SET);
340
    avio_skip(s->pb, 4);
341

    
342
    s->start_time = 0;
343

    
344
    return 0;
345
}
346

    
347
static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
348
{
349
    av_free(st->codec->extradata);
350
    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
351
    if (!st->codec->extradata)
352
        return AVERROR(ENOMEM);
353
    st->codec->extradata_size = size;
354
    avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
355
    return 0;
356
}
357

    
358
static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
359
{
360
    FLVContext *flv = s->priv_data;
361
    int ret, i, type, size, flags, is_audio;
362
    int64_t next, pos;
363
    int64_t dts, pts = AV_NOPTS_VALUE;
364
    AVStream *st = NULL;
365

    
366
 for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
367
    pos = avio_tell(s->pb);
368
    type = avio_r8(s->pb);
369
    size = avio_rb24(s->pb);
370
    dts = avio_rb24(s->pb);
371
    dts |= avio_r8(s->pb) << 24;
372
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts);
373
    if (url_feof(s->pb))
374
        return AVERROR_EOF;
375
    avio_skip(s->pb, 3); /* stream id, always 0 */
376
    flags = 0;
377

    
378
    if(size == 0)
379
        continue;
380

    
381
    next= size + avio_tell(s->pb);
382

    
383
    if (type == FLV_TAG_TYPE_AUDIO) {
384
        is_audio=1;
385
        flags = avio_r8(s->pb);
386
        size--;
387
    } else if (type == FLV_TAG_TYPE_VIDEO) {
388
        is_audio=0;
389
        flags = avio_r8(s->pb);
390
        size--;
391
        if ((flags & 0xf0) == 0x50) /* video info / command frame */
392
            goto skip;
393
    } else {
394
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
395
            flv_read_metabody(s, next);
396
        else /* skip packet */
397
            av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
398
    skip:
399
        avio_seek(s->pb, next, SEEK_SET);
400
        continue;
401
    }
402

    
403
    /* skip empty data packets */
404
    if (!size)
405
        continue;
406

    
407
    /* now find stream */
408
    for(i=0;i<s->nb_streams;i++) {
409
        st = s->streams[i];
410
        if (st->id == is_audio)
411
            break;
412
    }
413
    if(i == s->nb_streams){
414
        av_log(s, AV_LOG_ERROR, "invalid stream\n");
415
        st= create_stream(s, is_audio);
416
        s->ctx_flags &= ~AVFMTCTX_NOHEADER;
417
    }
418
//    av_log(s, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
419
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
420
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
421
       || st->discard >= AVDISCARD_ALL
422
       ){
423
        avio_seek(s->pb, next, SEEK_SET);
424
        continue;
425
    }
426
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
427
        av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
428
    break;
429
 }
430

    
431
    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
432
    if(s->pb->seekable && (!s->duration || s->duration==AV_NOPTS_VALUE)){
433
        int size;
434
        const int64_t pos= avio_tell(s->pb);
435
        const int64_t fsize= avio_size(s->pb);
436
        avio_seek(s->pb, fsize-4, SEEK_SET);
437
        size= avio_rb32(s->pb);
438
        avio_seek(s->pb, fsize-3-size, SEEK_SET);
439
        if(size == avio_rb24(s->pb) + 11){
440
            uint32_t ts = avio_rb24(s->pb);
441
            ts |= avio_r8(s->pb) << 24;
442
            s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
443
        }
444
        avio_seek(s->pb, pos, SEEK_SET);
445
    }
446

    
447
    if(is_audio){
448
        if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
449
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
450
            st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
451
            st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
452
        }
453
        if(!st->codec->codec_id){
454
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
455
        }
456
    }else{
457
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
458
    }
459

    
460
    if (st->codec->codec_id == CODEC_ID_AAC ||
461
        st->codec->codec_id == CODEC_ID_H264) {
462
        int type = avio_r8(s->pb);
463
        size--;
464
        if (st->codec->codec_id == CODEC_ID_H264) {
465
            int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
466
            pts = dts + cts;
467
            if (cts < 0) { // dts are wrong
468
                flv->wrong_dts = 1;
469
                av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
470
            }
471
            if (flv->wrong_dts)
472
                dts = AV_NOPTS_VALUE;
473
        }
474
        if (type == 0) {
475
            if ((ret = flv_get_extradata(s, st, size)) < 0)
476
                return ret;
477
            if (st->codec->codec_id == CODEC_ID_AAC) {
478
                MPEG4AudioConfig cfg;
479
                ff_mpeg4audio_get_config(&cfg, st->codec->extradata,
480
                                         st->codec->extradata_size);
481
                st->codec->channels = cfg.channels;
482
                if (cfg.ext_sample_rate)
483
                    st->codec->sample_rate = cfg.ext_sample_rate;
484
                else
485
                    st->codec->sample_rate = cfg.sample_rate;
486
                av_dlog(s, "mp4a config channels %d sample rate %d\n",
487
                        st->codec->channels, st->codec->sample_rate);
488
            }
489

    
490
            ret = AVERROR(EAGAIN);
491
            goto leave;
492
        }
493
    }
494

    
495
    /* skip empty data packets */
496
    if (!size) {
497
        ret = AVERROR(EAGAIN);
498
        goto leave;
499
    }
500

    
501
    ret= av_get_packet(s->pb, pkt, size);
502
    if (ret < 0) {
503
        return AVERROR(EIO);
504
    }
505
    /* note: we need to modify the packet size here to handle the last
506
       packet */
507
    pkt->size = ret;
508
    pkt->dts = dts;
509
    pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
510
    pkt->stream_index = st->index;
511

    
512
    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
513
        pkt->flags |= AV_PKT_FLAG_KEY;
514

    
515
leave:
516
    avio_skip(s->pb, 4);
517
    return ret;
518
}
519

    
520
static int flv_read_seek(AVFormatContext *s, int stream_index,
521
    int64_t ts, int flags)
522
{
523
    return ffio_read_seek(s->pb, stream_index, ts, flags);
524
}
525

    
526
#if 0 /* don't know enough to implement this */
527
static int flv_read_seek2(AVFormatContext *s, int stream_index,
528
    int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
529
{
530
    int ret = AVERROR(ENOSYS);
531

532
    if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD;
533

534
    if (!s->pb->seekable) {
535
        if (stream_index < 0) {
536
            stream_index = av_find_default_stream_index(s);
537
            if (stream_index < 0)
538
                return -1;
539

540
            /* timestamp for default must be expressed in AV_TIME_BASE units */
541
            ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE,
542
                flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
543
        }
544
        ret = ffio_read_seek(s->pb, stream_index, ts, flags);
545
    }
546

547
    if (ret == AVERROR(ENOSYS))
548
        ret = av_seek_frame(s, stream_index, ts, flags);
549
    return ret;
550
}
551
#endif
552

    
553
AVInputFormat ff_flv_demuxer = {
554
    "flv",
555
    NULL_IF_CONFIG_SMALL("FLV format"),
556
    sizeof(FLVContext),
557
    flv_probe,
558
    flv_read_header,
559
    flv_read_packet,
560
    .read_seek = flv_read_seek,
561
#if 0
562
    .read_seek2 = flv_read_seek2,
563
#endif
564
    .extensions = "flv",
565
    .value = CODEC_ID_FLV1,
566
};