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ffmpeg / libavformat / flvdec.c @ 8509fc7b

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1 d4f5d74a Garrick Meeker
/*
2 7fbde343 Aurelien Jacobs
 * FLV demuxer
3 d4f5d74a Garrick Meeker
 * Copyright (c) 2003 The FFmpeg Project.
4
 *
5 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
6
 *
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 * FFmpeg is free software; you can redistribute it and/or
8 d4f5d74a Garrick Meeker
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
10 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
11 d4f5d74a Garrick Meeker
 *
12 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * 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
18 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
19 5509bffa Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 246f86a4 Aurelien Jacobs
 *
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 *
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 * This demuxer will generate a 1 byte extradata for VP6F content.
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 * It is composed of:
24
 *  - upper 4bits: difference between encoded width and visible width
25
 *  - lower 4bits: difference between encoded height and visible height
26 d4f5d74a Garrick Meeker
 */
27
#include "avformat.h"
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#include "flv.h"
29 d4f5d74a Garrick Meeker
30
static int flv_probe(AVProbeData *p)
31
{
32
    const uint8_t *d;
33
34
    if (p->buf_size < 6)
35
        return 0;
36
    d = p->buf;
37 74248229 Michael Niedermayer
    if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0) {
38
        return AVPROBE_SCORE_MAX;
39 d4f5d74a Garrick Meeker
    }
40
    return 0;
41
}
42
43 428cc588 Allan Hsu
static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
44
    AVCodecContext *acodec = astream->codec;
45
    switch(flv_codecid) {
46
        //no distinction between S16 and S8 PCM codec flags
47
        case FLV_CODECID_PCM_BE:
48
            acodec->codec_id = acodec->bits_per_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16BE; break;
49
        case FLV_CODECID_PCM_LE:
50
            acodec->codec_id = acodec->bits_per_sample == 8 ? CODEC_ID_PCM_S8 : CODEC_ID_PCM_S16LE; break;
51
        case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF;                              break;
52
        case FLV_CODECID_MP3  : acodec->codec_id = CODEC_ID_MP3      ; astream->need_parsing = 1  ; break;
53
        case FLV_CODECID_NELLYMOSER_8HZ_MONO:
54
            acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
55
        case FLV_CODECID_NELLYMOSER:
56
        default:
57
            av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
58
            acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
59
    }
60
}
61
62
static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
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    AVCodecContext *vcodec = vstream->codec;
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    switch(flv_codecid) {
65
        case FLV_CODECID_H263  : vcodec->codec_id = CODEC_ID_FLV1   ; break;
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        case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
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        case FLV_CODECID_VP6   : vcodec->codec_id = CODEC_ID_VP6F   ;
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            if(vcodec->extradata_size != 1) {
69
                vcodec->extradata_size = 1;
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                vcodec->extradata = av_malloc(1);
71
            }
72
            vcodec->extradata[0] = get_byte(&s->pb);
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            return 1; // 1 byte body size adjustment for flv_read_packet()
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        default:
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            av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
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            vcodec->codec_tag = flv_codecid;
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    }
78
79
    return 0;
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}
81
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static int amf_get_string(ByteIOContext *ioc, char *buffer, int buffsize) {
83 759dd138 Michael Niedermayer
    int length = get_be16(ioc);
84 896bcd2e Michael Niedermayer
    if(length >= buffsize) {
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        url_fskip(ioc, length);
86 759dd138 Michael Niedermayer
        return -1;
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    }
88
89
    get_buffer(ioc, buffer, length);
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    buffer[length] = '\0';
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    return length;
94
}
95
96 428cc588 Allan Hsu
static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, unsigned int max_pos, int depth) {
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    AVCodecContext *acodec, *vcodec;
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    ByteIOContext *ioc;
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    AMFDataType amf_type;
100
    char str_val[256];
101
    double num_val;
102
103
    num_val = 0;
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    ioc = &s->pb;
105
106
    amf_type = get_byte(ioc);
107
108
    switch(amf_type) {
109
        case AMF_DATA_TYPE_NUMBER:
110
            num_val = av_int2dbl(get_be64(ioc)); break;
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        case AMF_DATA_TYPE_BOOL:
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            num_val = get_byte(ioc); break;
113
        case AMF_DATA_TYPE_STRING:
114
            if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
115
                return -1;
116
            break;
117
        case AMF_DATA_TYPE_OBJECT: {
118
            unsigned int keylen;
119
120
            while(url_ftell(ioc) < max_pos - 2 && (keylen = get_be16(ioc))) {
121
                url_fskip(ioc, keylen); //skip key string
122
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
123
                    return -1; //if we couldn't skip, bomb out.
124
            }
125
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
126
                return -1;
127
        }
128
            break;
129
        case AMF_DATA_TYPE_NULL:
130
        case AMF_DATA_TYPE_UNDEFINED:
131
        case AMF_DATA_TYPE_UNSUPPORTED:
132
            break; //these take up no additional space
133
        case AMF_DATA_TYPE_MIXEDARRAY:
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            url_fskip(ioc, 4); //skip 32-bit max array index
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            while(url_ftell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
136
                //this is the only case in which we would want a nested parse to not skip over the object
137
                if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
138
                    return -1;
139
            }
140
            if(get_byte(ioc) != AMF_END_OF_OBJECT)
141
                return -1;
142
            break;
143
        case AMF_DATA_TYPE_ARRAY: {
144
            unsigned int arraylen, i;
145
146
            arraylen = get_be32(ioc);
147
            for(i = 0; i < arraylen && url_ftell(ioc) < max_pos - 1; i++) {
148
                if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
149
                    return -1; //if we couldn't skip, bomb out.
150
            }
151
        }
152
            break;
153
        case AMF_DATA_TYPE_DATE:
154
            url_fskip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
155
            break;
156
        default: //unsupported type, we couldn't skip
157
            return -1;
158
    }
159
160
    if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
161
        acodec = astream ? astream->codec : NULL;
162
        vcodec = vstream ? vstream->codec : NULL;
163
164
        if(amf_type == AMF_DATA_TYPE_BOOL) {
165
            if(!strcmp(key, "stereo") && acodec) acodec->channels = num_val > 0 ? 2 : 1;
166
        } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
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            if(!strcmp(key, "duration")) s->duration = num_val * AV_TIME_BASE;
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//            else if(!strcmp(key, "width")  && vcodec && num_val > 0) vcodec->width  = num_val;
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//            else if(!strcmp(key, "height") && vcodec && num_val > 0) vcodec->height = num_val;
170 428cc588 Allan Hsu
            else if(!strcmp(key, "audiocodecid") && acodec) flv_set_audio_codec(s, astream, (int)num_val << FLV_AUDIO_CODECID_OFFSET);
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            else if(!strcmp(key, "videocodecid") && vcodec) flv_set_video_codec(s, vstream, (int)num_val);
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            else if(!strcmp(key, "audiosamplesize") && acodec && num_val >= 0) {
173
                acodec->bits_per_sample = num_val;
174
                //we may have to rewrite a previously read codecid because FLV only marks PCM endianness.
175
                if(num_val == 8 && (acodec->codec_id == CODEC_ID_PCM_S16BE || acodec->codec_id == CODEC_ID_PCM_S16LE))
176
                    acodec->codec_id = CODEC_ID_PCM_S8;
177
            }
178
            else if(!strcmp(key, "audiosamplerate") && acodec && num_val >= 0) {
179
                //some tools, like FLVTool2, write consistently approximate metadata sample rates
180
                switch((int)num_val) {
181
                    case 44000: acodec->sample_rate = 44100  ; break;
182
                    case 22000: acodec->sample_rate = 22050  ; break;
183
                    case 11000: acodec->sample_rate = 11025  ; break;
184
                    case 5000 : acodec->sample_rate = 5512   ; break;
185
                    default   : acodec->sample_rate = num_val;
186
                }
187
            }
188
        }
189
    }
190
191
    return 0;
192
}
193
194
static int flv_read_metabody(AVFormatContext *s, unsigned int next_pos) {
195
    AMFDataType type;
196
    AVStream *stream, *astream, *vstream;
197
    ByteIOContext *ioc;
198
    int i, keylen;
199
    char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
200
201
    astream = NULL;
202
    vstream = NULL;
203
    keylen = 0;
204
    ioc = &s->pb;
205
206
    //first object needs to be "onMetaData" string
207
    type = get_byte(ioc);
208
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
209
        return -1;
210
211
    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
212
    for(i = 0; i < s->nb_streams; i++) {
213
        stream = s->streams[i];
214
        if     (stream->codec->codec_type == CODEC_TYPE_AUDIO) astream = stream;
215
        else if(stream->codec->codec_type == CODEC_TYPE_VIDEO) vstream = stream;
216
    }
217
218
    //parse the second object (we want a mixed array)
219
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
220
        return -1;
221
222
    return 0;
223
}
224
225 d4f5d74a Garrick Meeker
static int flv_read_header(AVFormatContext *s,
226
                           AVFormatParameters *ap)
227
{
228 15f14fc7 Michael Niedermayer
    int offset, flags;
229 4eb0c665 Michael Niedermayer
    AVStream *st;
230 d4f5d74a Garrick Meeker
231
    url_fskip(&s->pb, 4);
232
    flags = get_byte(&s->pb);
233 031311cb Alex Beregszaszi
    /* old flvtool cleared this field */
234
    /* FIXME: better fix needed */
235
    if (!flags) {
236
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
237
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
238
    }
239 d4f5d74a Garrick Meeker
240 4eb0c665 Michael Niedermayer
    if(flags & FLV_HEADER_FLAG_HASVIDEO){
241
        st = av_new_stream(s, 0);
242
        if (!st)
243
            return AVERROR_NOMEM;
244
        st->codec->codec_type = CODEC_TYPE_VIDEO;
245
        av_set_pts_info(st, 24, 1, 1000); /* 24 bit pts in ms */
246
    }
247
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
248
        st = av_new_stream(s, 1);
249
        if (!st)
250
            return AVERROR_NOMEM;
251
        st->codec->codec_type = CODEC_TYPE_AUDIO;
252
        av_set_pts_info(st, 24, 1, 1000); /* 24 bit pts in ms */
253
    }
254
255 d4f5d74a Garrick Meeker
    offset = get_be32(&s->pb);
256
    url_fseek(&s->pb, offset, SEEK_SET);
257
258 aeb20f7f Nazo
    s->start_time = 0;
259
260 d4f5d74a Garrick Meeker
    return 0;
261
}
262
263
static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
264
{
265 aeb20f7f Nazo
    int ret, i, type, size, pts, flags, is_audio, next, pos;
266 923bd441 Alex Beregszaszi
    AVStream *st = NULL;
267 115329f1 Diego Biurrun
268 068f2a22 Michael Niedermayer
 for(;;){
269 aeb20f7f Nazo
    pos = url_ftell(&s->pb);
270 d4f5d74a Garrick Meeker
    url_fskip(&s->pb, 4); /* size of previous packet */
271
    type = get_byte(&s->pb);
272
    size = get_be24(&s->pb);
273
    pts = get_be24(&s->pb);
274 92a26775 Michael Niedermayer
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, pts:%d\n", type, size, pts);
275 d4f5d74a Garrick Meeker
    if (url_feof(&s->pb))
276 0bd586c5 Mike Melanson
        return AVERROR_IO;
277 d4f5d74a Garrick Meeker
    url_fskip(&s->pb, 4); /* reserved */
278
    flags = 0;
279 115329f1 Diego Biurrun
280 068f2a22 Michael Niedermayer
    if(size == 0)
281
        continue;
282 115329f1 Diego Biurrun
283 dd9f5916 Michael Niedermayer
    next= size + url_ftell(&s->pb);
284
285 6cac3a3b Allan Hsu
    if (type == FLV_TAG_TYPE_AUDIO) {
286 068f2a22 Michael Niedermayer
        is_audio=1;
287 d4f5d74a Garrick Meeker
        flags = get_byte(&s->pb);
288 6cac3a3b Allan Hsu
    } else if (type == FLV_TAG_TYPE_VIDEO) {
289 068f2a22 Michael Niedermayer
        is_audio=0;
290 d4f5d74a Garrick Meeker
        flags = get_byte(&s->pb);
291
    } else {
292 428cc588 Allan Hsu
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
293
            flv_read_metabody(s, next);
294
        else /* skip packet */
295
            av_log(s, AV_LOG_ERROR, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
296 dd9f5916 Michael Niedermayer
        url_fseek(&s->pb, next, SEEK_SET);
297 068f2a22 Michael Niedermayer
        continue;
298 d4f5d74a Garrick Meeker
    }
299
300
    /* now find stream */
301
    for(i=0;i<s->nb_streams;i++) {
302
        st = s->streams[i];
303 068f2a22 Michael Niedermayer
        if (st->id == is_audio)
304
            break;
305 d4f5d74a Garrick Meeker
    }
306 068f2a22 Michael Niedermayer
    if(i == s->nb_streams){
307 4eb0c665 Michael Niedermayer
        av_log(NULL, AV_LOG_ERROR, "invalid stream\n");
308
        url_fseek(&s->pb, next, SEEK_SET);
309
        continue;
310 6ed08157 Michael Niedermayer
    }
311 f3356e9c Michael Niedermayer
//    av_log(NULL, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
312 6cac3a3b Allan Hsu
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
313
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
314 f3356e9c Michael Niedermayer
       || st->discard >= AVDISCARD_ALL
315
       ){
316 dd9f5916 Michael Niedermayer
        url_fseek(&s->pb, next, SEEK_SET);
317 b9866ebc Michael Niedermayer
        continue;
318
    }
319 6cac3a3b Allan Hsu
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
320 aeb20f7f Nazo
        av_add_index_entry(st, pos, pts, size, 0, AVINDEX_KEYFRAME);
321 068f2a22 Michael Niedermayer
    break;
322
 }
323
324 15f14fc7 Michael Niedermayer
    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
325
    if(!url_is_streamed(&s->pb) && s->duration==AV_NOPTS_VALUE){
326
        int size;
327
        const int pos= url_ftell(&s->pb);
328
        const int fsize= url_fsize(&s->pb);
329
        url_fseek(&s->pb, fsize-4, SEEK_SET);
330
        size= get_be32(&s->pb);
331
        url_fseek(&s->pb, fsize-3-size, SEEK_SET);
332
        if(size == get_be24(&s->pb) + 11){
333
            s->duration= get_be24(&s->pb) * (int64_t)AV_TIME_BASE / 1000;
334
        }
335
        url_fseek(&s->pb, pos, SEEK_SET);
336
    }
337
338 068f2a22 Michael Niedermayer
    if(is_audio){
339 428cc588 Allan Hsu
        if(!st->codec->sample_rate || !st->codec->bits_per_sample || (!st->codec->codec_id && !st->codec->codec_tag)) {
340 6cac3a3b Allan Hsu
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
341
            if((flags & FLV_AUDIO_CODECID_MASK) == FLV_CODECID_NELLYMOSER_8HZ_MONO)
342 01f4895c Michael Niedermayer
                st->codec->sample_rate= 8000;
343 068f2a22 Michael Niedermayer
            else
344 6cac3a3b Allan Hsu
                st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
345
            st->codec->bits_per_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
346 428cc588 Allan Hsu
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
347 068f2a22 Michael Niedermayer
        }
348
    }else{
349 428cc588 Allan Hsu
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
350 bb01a3f0 Michael Niedermayer
    }
351
352 dd9f5916 Michael Niedermayer
    ret= av_get_packet(&s->pb, pkt, size - 1);
353 d4f5d74a Garrick Meeker
    if (ret <= 0) {
354 0bd586c5 Mike Melanson
        return AVERROR_IO;
355 d4f5d74a Garrick Meeker
    }
356
    /* note: we need to modify the packet size here to handle the last
357
       packet */
358
    pkt->size = ret;
359
    pkt->pts = pts;
360
    pkt->stream_index = st->index;
361 115329f1 Diego Biurrun
362 6cac3a3b Allan Hsu
    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
363 bb270c08 Diego Biurrun
        pkt->flags |= PKT_FLAG_KEY;
364 115329f1 Diego Biurrun
365 d4f5d74a Garrick Meeker
    return ret;
366
}
367
368
static int flv_read_close(AVFormatContext *s)
369
{
370
    return 0;
371
}
372
373 aeb20f7f Nazo
static int flv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
374
{
375
    AVStream *st = s->streams[stream_index];
376
    int index = av_index_search_timestamp(st, timestamp, flags);
377
    if (index < 0)
378
        return -1;
379
    url_fseek(&s->pb, st->index_entries[index].pos, SEEK_SET);
380
381
    return 0;
382
}
383
384 d2a067d1 Måns Rullgård
AVInputFormat flv_demuxer = {
385 d4f5d74a Garrick Meeker
    "flv",
386
    "flv format",
387
    0,
388
    flv_probe,
389
    flv_read_header,
390
    flv_read_packet,
391
    flv_read_close,
392 aeb20f7f Nazo
    flv_read_seek,
393 d4f5d74a Garrick Meeker
    .extensions = "flv",
394
    .value = CODEC_ID_FLV1,
395
};