3 * Copyright (c) 2003 The FFmpeg Project
5 * This demuxer will generate a 1 byte extradata for VP6F content.
7 * - upper 4bits: difference between encoded width and visible width
8 * - lower 4bits: difference between encoded height and visible height
10 * This file is part of FFmpeg.
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.
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.
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
27 #include "libavutil/avstring.h"
28 #include "libavutil/dict.h"
29 #include "libavutil/intfloat_readwrite.h"
30 #include "libavutil/mathematics.h"
31 #include "libavcodec/bytestream.h"
32 #include "libavcodec/mpeg4audio.h"
34 #include "avio_internal.h"
38 int wrong_dts; ///< wrong dts due to negative cts
41 static int flv_probe(AVProbeData *p)
46 if (d[0] == 'F' && d[1] == 'L' && d[2] == 'V' && d[3] < 5 && d[5]==0 && AV_RB32(d+5)>8) {
47 return AVPROBE_SCORE_MAX;
52 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, int flv_codecid) {
53 AVCodecContext *acodec = astream->codec;
55 //no distinction between S16 and S8 PCM codec flags
57 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 :
64 case FLV_CODECID_PCM_LE:
65 acodec->codec_id = acodec->bits_per_coded_sample == 8 ? CODEC_ID_PCM_U8 : CODEC_ID_PCM_S16LE; break;
66 case FLV_CODECID_AAC : acodec->codec_id = CODEC_ID_AAC; break;
67 case FLV_CODECID_ADPCM: acodec->codec_id = CODEC_ID_ADPCM_SWF; break;
68 case FLV_CODECID_SPEEX:
69 acodec->codec_id = CODEC_ID_SPEEX;
70 acodec->sample_rate = 16000;
72 case FLV_CODECID_MP3 : acodec->codec_id = CODEC_ID_MP3 ; astream->need_parsing = AVSTREAM_PARSE_FULL; break;
73 case FLV_CODECID_NELLYMOSER_8KHZ_MONO:
74 acodec->sample_rate = 8000; //in case metadata does not otherwise declare samplerate
75 acodec->codec_id = CODEC_ID_NELLYMOSER;
77 case FLV_CODECID_NELLYMOSER_16KHZ_MONO:
78 acodec->sample_rate = 16000;
79 acodec->codec_id = CODEC_ID_NELLYMOSER;
81 case FLV_CODECID_NELLYMOSER:
82 acodec->codec_id = CODEC_ID_NELLYMOSER;
85 av_log(s, AV_LOG_INFO, "Unsupported audio codec (%x)\n", flv_codecid >> FLV_AUDIO_CODECID_OFFSET);
86 acodec->codec_tag = flv_codecid >> FLV_AUDIO_CODECID_OFFSET;
90 static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream, int flv_codecid) {
91 AVCodecContext *vcodec = vstream->codec;
93 case FLV_CODECID_H263 : vcodec->codec_id = CODEC_ID_FLV1 ; break;
94 case FLV_CODECID_REALH263: vcodec->codec_id = CODEC_ID_H263 ; break; // Really mean it this time
95 case FLV_CODECID_SCREEN: vcodec->codec_id = CODEC_ID_FLASHSV; break;
96 case FLV_CODECID_SCREEN2: vcodec->codec_id = CODEC_ID_FLASHSV2; break;
97 case FLV_CODECID_VP6 : vcodec->codec_id = CODEC_ID_VP6F ;
98 case FLV_CODECID_VP6A :
99 if(flv_codecid == FLV_CODECID_VP6A)
100 vcodec->codec_id = CODEC_ID_VP6A;
101 if(vcodec->extradata_size != 1) {
102 vcodec->extradata_size = 1;
103 vcodec->extradata = av_malloc(1);
105 vcodec->extradata[0] = avio_r8(s->pb);
106 return 1; // 1 byte body size adjustment for flv_read_packet()
107 case FLV_CODECID_H264:
108 vcodec->codec_id = CODEC_ID_H264;
109 return 3; // not 4, reading packet type will consume one byte
110 case FLV_CODECID_MPEG4:
111 vcodec->codec_id = CODEC_ID_MPEG4;
114 av_log(s, AV_LOG_INFO, "Unsupported video codec (%x)\n", flv_codecid);
115 vcodec->codec_tag = flv_codecid;
121 static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
122 int length = avio_rb16(ioc);
123 if(length >= buffsize) {
124 avio_skip(ioc, length);
128 avio_read(ioc, buffer, length);
130 buffer[length] = '\0';
135 static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
136 unsigned int timeslen = 0, fileposlen = 0, i;
138 int64_t *times = NULL;
139 int64_t *filepositions = NULL;
140 int ret = AVERROR(ENOSYS);
141 int64_t initial_pos = avio_tell(ioc);
142 AVDictionaryEntry *creator = av_dict_get(s->metadata, "metadatacreator",
145 if (creator && !strcmp(creator->value, "MEGA")) {
146 /* Files with this metadatacreator tag seem to have filepositions
147 * pointing at the 4 trailer bytes of the previous packet,
148 * which isn't the norm (nor what we expect here, nor what
149 * jwplayer + lighttpd expect, nor what flvtool2 produces).
150 * Just ignore the index in this case, instead of risking trying
151 * to adjust it to something that might or might not work. */
155 if(vstream->nb_index_entries>0){
156 av_log(s, AV_LOG_WARNING, "Skiping duplicate index\n");
160 while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
161 int64_t** current_array;
162 unsigned int arraylen;
164 // Expect array object in context
165 if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
168 arraylen = avio_rb32(ioc);
172 if (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
173 current_array= ×
175 }else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
176 current_array= &filepositions;
177 fileposlen= arraylen;
178 }else // unexpected metatag inside keyframes, will not use such metadata for indexing
181 if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
182 ret = AVERROR(ENOMEM);
186 for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
187 if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
189 current_array[0][i] = av_int2dbl(avio_rb64(ioc));
191 if (times && filepositions) {
192 // All done, exiting at a position allowing amf_parse_object
193 // to finish parsing the object
199 if (timeslen == fileposlen && fileposlen && max_pos <= filepositions[0]) {
200 for(i = 0; i < timeslen; i++)
201 av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
203 av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
207 av_freep(&filepositions);
208 avio_seek(ioc, initial_pos, SEEK_SET);
212 static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vstream, const char *key, int64_t max_pos, int depth) {
213 AVCodecContext *acodec, *vcodec;
215 AMFDataType amf_type;
222 amf_type = avio_r8(ioc);
225 case AMF_DATA_TYPE_NUMBER:
226 num_val = av_int2dbl(avio_rb64(ioc)); break;
227 case AMF_DATA_TYPE_BOOL:
228 num_val = avio_r8(ioc); break;
229 case AMF_DATA_TYPE_STRING:
230 if(amf_get_string(ioc, str_val, sizeof(str_val)) < 0)
233 case AMF_DATA_TYPE_OBJECT: {
236 if ((vstream || astream) && ioc->seekable && key && !strcmp(KEYFRAMES_TAG, key) && depth == 1)
237 if (parse_keyframes_index(s, ioc, vstream ? vstream : astream,
239 av_log(s, AV_LOG_ERROR, "Keyframe index parsing failed\n");
241 while(avio_tell(ioc) < max_pos - 2 && (keylen = avio_rb16(ioc))) {
242 avio_skip(ioc, keylen); //skip key string
243 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
244 return -1; //if we couldn't skip, bomb out.
246 if(avio_r8(ioc) != AMF_END_OF_OBJECT)
250 case AMF_DATA_TYPE_NULL:
251 case AMF_DATA_TYPE_UNDEFINED:
252 case AMF_DATA_TYPE_UNSUPPORTED:
253 break; //these take up no additional space
254 case AMF_DATA_TYPE_MIXEDARRAY:
255 avio_skip(ioc, 4); //skip 32-bit max array index
256 while(avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
257 //this is the only case in which we would want a nested parse to not skip over the object
258 if(amf_parse_object(s, astream, vstream, str_val, max_pos, depth + 1) < 0)
261 if(avio_r8(ioc) != AMF_END_OF_OBJECT)
264 case AMF_DATA_TYPE_ARRAY: {
265 unsigned int arraylen, i;
267 arraylen = avio_rb32(ioc);
268 for(i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
269 if(amf_parse_object(s, NULL, NULL, NULL, max_pos, depth + 1) < 0)
270 return -1; //if we couldn't skip, bomb out.
274 case AMF_DATA_TYPE_DATE:
275 avio_skip(ioc, 8 + 2); //timestamp (double) and UTC offset (int16)
277 default: //unsupported type, we couldn't skip
281 if(depth == 1 && key) { //only look for metadata values when we are not nested and key != NULL
282 acodec = astream ? astream->codec : NULL;
283 vcodec = vstream ? vstream->codec : NULL;
285 if (amf_type == AMF_DATA_TYPE_NUMBER) {
286 if (!strcmp(key, "duration"))
287 s->duration = num_val * AV_TIME_BASE;
288 else if (!strcmp(key, "videodatarate") && vcodec && 0 <= (int)(num_val * 1024.0))
289 vcodec->bit_rate = num_val * 1024.0;
290 else if (!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
291 acodec->bit_rate = num_val * 1024.0;
294 if (!strcmp(key, "duration") ||
295 !strcmp(key, "filesize") ||
296 !strcmp(key, "width") ||
297 !strcmp(key, "height") ||
298 !strcmp(key, "videodatarate") ||
299 !strcmp(key, "framerate") ||
300 !strcmp(key, "videocodecid") ||
301 !strcmp(key, "audiodatarate") ||
302 !strcmp(key, "audiosamplerate") ||
303 !strcmp(key, "audiosamplesize") ||
304 !strcmp(key, "stereo") ||
305 !strcmp(key, "audiocodecid"))
308 if(amf_type == AMF_DATA_TYPE_BOOL) {
309 av_strlcpy(str_val, num_val > 0 ? "true" : "false", sizeof(str_val));
310 av_dict_set(&s->metadata, key, str_val, 0);
311 } else if(amf_type == AMF_DATA_TYPE_NUMBER) {
312 snprintf(str_val, sizeof(str_val), "%.f", num_val);
313 av_dict_set(&s->metadata, key, str_val, 0);
314 } else if(amf_type == AMF_DATA_TYPE_OBJECT){
315 if(s->nb_streams==1 && ((!acodec && !strcmp(key, "audiocodecid")) || (!vcodec && !strcmp(key, "videocodecid")))){
316 s->ctx_flags &= ~AVFMTCTX_NOHEADER; //If there is either audio/video missing, codecid will be an empty object
318 } else if (amf_type == AMF_DATA_TYPE_STRING)
319 av_dict_set(&s->metadata, key, str_val, 0);
325 static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
327 AVStream *stream, *astream, *vstream, *dstream;
330 char buffer[11]; //only needs to hold the string "onMetaData". Anything longer is something we don't want.
332 vstream = astream = dstream = NULL;
335 //first object needs to be "onMetaData" string
337 if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
340 //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
341 for(i = 0; i < s->nb_streams; i++) {
342 stream = s->streams[i];
343 if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) vstream = stream;
344 else if(stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) astream = stream;
345 else if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) dstream = stream;
348 //parse the second object (we want a mixed array)
349 if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
355 static AVStream *create_stream(AVFormatContext *s, int stream_type){
356 AVStream *st = avformat_new_stream(s, NULL);
359 st->id = stream_type;
360 switch(stream_type) {
361 case FLV_STREAM_TYPE_VIDEO: st->codec->codec_type = AVMEDIA_TYPE_VIDEO; break;
362 case FLV_STREAM_TYPE_AUDIO: st->codec->codec_type = AVMEDIA_TYPE_AUDIO; break;
363 case FLV_STREAM_TYPE_DATA:
364 st->codec->codec_type = AVMEDIA_TYPE_DATA;
365 st->codec->codec_id = CODEC_ID_NONE; // Going to rely on copy for now
366 av_log(s, AV_LOG_DEBUG, "Data stream created\n");
368 av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
372 static int flv_read_header(AVFormatContext *s,
373 AVFormatParameters *ap)
378 flags = avio_r8(s->pb);
379 /* old flvtool cleared this field */
380 /* FIXME: better fix needed */
382 flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
383 av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
386 if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
387 != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
388 s->ctx_flags |= AVFMTCTX_NOHEADER;
390 if(flags & FLV_HEADER_FLAG_HASVIDEO){
391 if(!create_stream(s, FLV_STREAM_TYPE_VIDEO))
392 return AVERROR(ENOMEM);
394 if(flags & FLV_HEADER_FLAG_HASAUDIO){
395 if(!create_stream(s, FLV_STREAM_TYPE_AUDIO))
396 return AVERROR(ENOMEM);
398 // Flag doesn't indicate whether or not there is script-data present. Must
399 // create that stream if it's encountered.
401 offset = avio_rb32(s->pb);
402 avio_seek(s->pb, offset, SEEK_SET);
410 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
412 av_free(st->codec->extradata);
413 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
414 if (!st->codec->extradata)
415 return AVERROR(ENOMEM);
416 st->codec->extradata_size = size;
417 avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
421 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
423 FLVContext *flv = s->priv_data;
424 int ret, i, type, size, flags;
427 int64_t dts, pts = AV_NOPTS_VALUE;
430 for(;;avio_skip(s->pb, 4)){ /* pkt size is repeated at end. skip it */
431 pos = avio_tell(s->pb);
432 type = avio_r8(s->pb);
433 size = avio_rb24(s->pb);
434 dts = avio_rb24(s->pb);
435 dts |= avio_r8(s->pb) << 24;
436 av_dlog(s, "type:%d, size:%d, dts:%"PRId64"\n", type, size, dts);
439 avio_skip(s->pb, 3); /* stream id, always 0 */
445 next= size + avio_tell(s->pb);
447 if (type == FLV_TAG_TYPE_AUDIO) {
448 stream_type=FLV_STREAM_TYPE_AUDIO;
449 flags = avio_r8(s->pb);
451 } else if (type == FLV_TAG_TYPE_VIDEO) {
452 stream_type=FLV_STREAM_TYPE_VIDEO;
453 flags = avio_r8(s->pb);
455 if ((flags & 0xf0) == 0x50) /* video info / command frame */
457 } else if (type == FLV_TAG_TYPE_META) {
458 if (size > 13+1+4 && dts == 0) { // Header-type metadata stuff
459 flv_read_metabody(s, next);
461 } else if (dts != 0) { // Script-data "special" metadata frames - don't skip
462 stream_type=FLV_STREAM_TYPE_DATA;
467 av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
469 avio_seek(s->pb, next, SEEK_SET);
473 /* skip empty data packets */
477 /* now find stream */
478 for(i=0;i<s->nb_streams;i++) {
480 if (st->id == stream_type)
483 if(i == s->nb_streams){
484 av_log(s, AV_LOG_WARNING, "Stream discovered after head already parsed\n");
485 st= create_stream(s, stream_type);
486 s->ctx_flags &= ~AVFMTCTX_NOHEADER;
488 av_dlog(s, "%d %X %d \n", stream_type, flags, st->discard);
489 if( (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY || (stream_type == FLV_STREAM_TYPE_AUDIO)))
490 ||(st->discard >= AVDISCARD_BIDIR && ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && (stream_type == FLV_STREAM_TYPE_VIDEO)))
491 || st->discard >= AVDISCARD_ALL
493 avio_seek(s->pb, next, SEEK_SET);
496 if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
497 av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
501 // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
502 if(s->pb->seekable && (!s->duration || s->duration==AV_NOPTS_VALUE)){
504 const int64_t pos= avio_tell(s->pb);
505 const int64_t fsize= avio_size(s->pb);
506 avio_seek(s->pb, fsize-4, SEEK_SET);
507 size= avio_rb32(s->pb);
508 avio_seek(s->pb, fsize-3-size, SEEK_SET);
509 if(size == avio_rb24(s->pb) + 11){
510 uint32_t ts = avio_rb24(s->pb);
511 ts |= avio_r8(s->pb) << 24;
512 s->duration = ts * (int64_t)AV_TIME_BASE / 1000;
514 avio_seek(s->pb, pos, SEEK_SET);
517 if(stream_type == FLV_STREAM_TYPE_AUDIO){
518 if(!st->codec->channels || !st->codec->sample_rate || !st->codec->bits_per_coded_sample) {
519 st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
520 st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
521 st->codec->bits_per_coded_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
523 if(!st->codec->codec_id){
524 flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
526 } else if(stream_type == FLV_STREAM_TYPE_VIDEO) {
527 size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
530 if (st->codec->codec_id == CODEC_ID_AAC ||
531 st->codec->codec_id == CODEC_ID_H264 ||
532 st->codec->codec_id == CODEC_ID_MPEG4) {
533 int type = avio_r8(s->pb);
535 if (st->codec->codec_id == CODEC_ID_H264 || st->codec->codec_id == CODEC_ID_MPEG4) {
536 int32_t cts = (avio_rb24(s->pb)+0xff800000)^0xff800000; // sign extension
538 if (cts < 0) { // dts are wrong
540 av_log(s, AV_LOG_WARNING, "negative cts, previous timestamps might be wrong\n");
543 dts = AV_NOPTS_VALUE;
546 if (type == 0 && !st->codec->extradata) {
547 if ((ret = flv_get_extradata(s, st, size)) < 0)
549 if (st->codec->codec_id == CODEC_ID_AAC) {
550 MPEG4AudioConfig cfg;
551 avpriv_mpeg4audio_get_config(&cfg, st->codec->extradata,
552 st->codec->extradata_size);
553 st->codec->channels = cfg.channels;
554 if (cfg.ext_sample_rate)
555 st->codec->sample_rate = cfg.ext_sample_rate;
557 st->codec->sample_rate = cfg.sample_rate;
558 av_dlog(s, "mp4a config channels %d sample rate %d\n",
559 st->codec->channels, st->codec->sample_rate);
562 ret = AVERROR(EAGAIN);
567 /* skip empty data packets */
569 ret = AVERROR(EAGAIN);
573 ret= av_get_packet(s->pb, pkt, size);
577 /* note: we need to modify the packet size here to handle the last
581 pkt->pts = pts == AV_NOPTS_VALUE ? dts : pts;
582 pkt->stream_index = st->index;
584 if ( stream_type == FLV_STREAM_TYPE_AUDIO ||
585 ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY) ||
586 stream_type == FLV_STREAM_TYPE_DATA)
587 pkt->flags |= AV_PKT_FLAG_KEY;
594 static int flv_read_seek(AVFormatContext *s, int stream_index,
595 int64_t ts, int flags)
597 return avio_seek_time(s->pb, stream_index, ts, flags);
600 #if 0 /* don't know enough to implement this */
601 static int flv_read_seek2(AVFormatContext *s, int stream_index,
602 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
604 int ret = AVERROR(ENOSYS);
606 if (ts - min_ts > (uint64_t)(max_ts - ts)) flags |= AVSEEK_FLAG_BACKWARD;
608 if (!s->pb->seekable) {
609 if (stream_index < 0) {
610 stream_index = av_find_default_stream_index(s);
611 if (stream_index < 0)
614 /* timestamp for default must be expressed in AV_TIME_BASE units */
615 ts = av_rescale_rnd(ts, 1000, AV_TIME_BASE,
616 flags & AVSEEK_FLAG_BACKWARD ? AV_ROUND_DOWN : AV_ROUND_UP);
618 ret = avio_seek_time(s->pb, stream_index, ts, flags);
621 if (ret == AVERROR(ENOSYS))
622 ret = av_seek_frame(s, stream_index, ts, flags);
627 AVInputFormat ff_flv_demuxer = {
629 .long_name = NULL_IF_CONFIG_SMALL("FLV format"),
630 .priv_data_size = sizeof(FLVContext),
631 .read_probe = flv_probe,
632 .read_header = flv_read_header,
633 .read_packet = flv_read_packet,
634 .read_seek = flv_read_seek,
636 .read_seek2 = flv_read_seek2,
639 .value = CODEC_ID_FLV1,