3 * Copyright (c) 2003 The FFmpeg Project
5 * This file is part of FFmpeg.
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.
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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
23 #include "libavutil/dict.h"
24 #include "libavutil/intfloat.h"
25 #include "libavutil/avassert.h"
33 static const AVCodecTag flv_video_codec_ids[] = {
34 { AV_CODEC_ID_FLV1, FLV_CODECID_H263 },
35 { AV_CODEC_ID_H263, FLV_CODECID_REALH263 },
36 { AV_CODEC_ID_MPEG4, FLV_CODECID_MPEG4 },
37 { AV_CODEC_ID_FLASHSV, FLV_CODECID_SCREEN },
38 { AV_CODEC_ID_FLASHSV2, FLV_CODECID_SCREEN2 },
39 { AV_CODEC_ID_VP6F, FLV_CODECID_VP6 },
40 { AV_CODEC_ID_VP6, FLV_CODECID_VP6 },
41 { AV_CODEC_ID_VP6A, FLV_CODECID_VP6A },
42 { AV_CODEC_ID_H264, FLV_CODECID_H264 },
43 { AV_CODEC_ID_NONE, 0 }
46 static const AVCodecTag flv_audio_codec_ids[] = {
47 { AV_CODEC_ID_MP3, FLV_CODECID_MP3 >> FLV_AUDIO_CODECID_OFFSET },
48 { AV_CODEC_ID_PCM_U8, FLV_CODECID_PCM >> FLV_AUDIO_CODECID_OFFSET },
49 { AV_CODEC_ID_PCM_S16BE, FLV_CODECID_PCM >> FLV_AUDIO_CODECID_OFFSET },
50 { AV_CODEC_ID_PCM_S16LE, FLV_CODECID_PCM_LE >> FLV_AUDIO_CODECID_OFFSET },
51 { AV_CODEC_ID_ADPCM_SWF, FLV_CODECID_ADPCM >> FLV_AUDIO_CODECID_OFFSET },
52 { AV_CODEC_ID_AAC, FLV_CODECID_AAC >> FLV_AUDIO_CODECID_OFFSET },
53 { AV_CODEC_ID_NELLYMOSER, FLV_CODECID_NELLYMOSER >> FLV_AUDIO_CODECID_OFFSET },
54 { AV_CODEC_ID_PCM_MULAW, FLV_CODECID_PCM_MULAW >> FLV_AUDIO_CODECID_OFFSET },
55 { AV_CODEC_ID_PCM_ALAW, FLV_CODECID_PCM_ALAW >> FLV_AUDIO_CODECID_OFFSET },
56 { AV_CODEC_ID_SPEEX, FLV_CODECID_SPEEX >> FLV_AUDIO_CODECID_OFFSET },
57 { AV_CODEC_ID_NONE, 0 }
60 typedef struct FLVContext {
62 int64_t duration_offset;
63 int64_t filesize_offset;
65 int64_t delay; ///< first dts delay (needed for AVC & Speex)
68 typedef struct FLVStreamContext {
69 int64_t last_ts; ///< last timestamp for each stream
72 static int get_audio_flags(AVFormatContext *s, AVCodecContext *enc)
74 int flags = (enc->bits_per_coded_sample == 16) ? FLV_SAMPLESSIZE_16BIT
75 : FLV_SAMPLESSIZE_8BIT;
77 if (enc->codec_id == AV_CODEC_ID_AAC) // specs force these parameters
78 return FLV_CODECID_AAC | FLV_SAMPLERATE_44100HZ |
79 FLV_SAMPLESSIZE_16BIT | FLV_STEREO;
80 else if (enc->codec_id == AV_CODEC_ID_SPEEX) {
81 if (enc->sample_rate != 16000) {
82 av_log(s, AV_LOG_ERROR,
83 "FLV only supports wideband (16kHz) Speex audio\n");
84 return AVERROR(EINVAL);
86 if (enc->channels != 1) {
87 av_log(s, AV_LOG_ERROR, "FLV only supports mono Speex audio\n");
88 return AVERROR(EINVAL);
90 return FLV_CODECID_SPEEX | FLV_SAMPLERATE_11025HZ | FLV_SAMPLESSIZE_16BIT;
92 switch (enc->sample_rate) {
94 flags |= FLV_SAMPLERATE_44100HZ;
97 flags |= FLV_SAMPLERATE_22050HZ;
100 flags |= FLV_SAMPLERATE_11025HZ;
102 case 16000: // nellymoser only
103 case 8000: // nellymoser only
104 case 5512: // not MP3
105 if (enc->codec_id != AV_CODEC_ID_MP3) {
106 flags |= FLV_SAMPLERATE_SPECIAL;
110 av_log(s, AV_LOG_ERROR,
111 "FLV does not support sample rate %d, "
112 "choose from (44100, 22050, 11025)\n", enc->sample_rate);
113 return AVERROR(EINVAL);
117 if (enc->channels > 1)
120 switch (enc->codec_id) {
121 case AV_CODEC_ID_MP3:
122 flags |= FLV_CODECID_MP3 | FLV_SAMPLESSIZE_16BIT;
124 case AV_CODEC_ID_PCM_U8:
125 flags |= FLV_CODECID_PCM | FLV_SAMPLESSIZE_8BIT;
127 case AV_CODEC_ID_PCM_S16BE:
128 flags |= FLV_CODECID_PCM | FLV_SAMPLESSIZE_16BIT;
130 case AV_CODEC_ID_PCM_S16LE:
131 flags |= FLV_CODECID_PCM_LE | FLV_SAMPLESSIZE_16BIT;
133 case AV_CODEC_ID_ADPCM_SWF:
134 flags |= FLV_CODECID_ADPCM | FLV_SAMPLESSIZE_16BIT;
136 case AV_CODEC_ID_NELLYMOSER:
137 if (enc->sample_rate == 8000)
138 flags |= FLV_CODECID_NELLYMOSER_8KHZ_MONO | FLV_SAMPLESSIZE_16BIT;
139 else if (enc->sample_rate == 16000)
140 flags |= FLV_CODECID_NELLYMOSER_16KHZ_MONO | FLV_SAMPLESSIZE_16BIT;
142 flags |= FLV_CODECID_NELLYMOSER | FLV_SAMPLESSIZE_16BIT;
144 case AV_CODEC_ID_PCM_MULAW:
145 flags = FLV_CODECID_PCM_MULAW | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;
147 case AV_CODEC_ID_PCM_ALAW:
148 flags = FLV_CODECID_PCM_ALAW | FLV_SAMPLERATE_SPECIAL | FLV_SAMPLESSIZE_16BIT;
151 flags |= enc->codec_tag << 4;
154 av_log(s, AV_LOG_ERROR, "Audio codec '%s' not compatible with FLV\n",
155 avcodec_get_name(enc->codec_id));
156 return AVERROR(EINVAL);
162 static void put_amf_string(AVIOContext *pb, const char *str)
164 size_t len = strlen(str);
166 avio_write(pb, str, len);
169 static void put_avc_eos_tag(AVIOContext *pb, unsigned ts)
171 avio_w8(pb, FLV_TAG_TYPE_VIDEO);
172 avio_wb24(pb, 5); /* Tag Data Size */
173 avio_wb24(pb, ts); /* lower 24 bits of timestamp in ms */
174 avio_w8(pb, (ts >> 24) & 0x7F); /* MSB of ts in ms */
175 avio_wb24(pb, 0); /* StreamId = 0 */
176 avio_w8(pb, 23); /* ub[4] FrameType = 1, ub[4] CodecId = 7 */
177 avio_w8(pb, 2); /* AVC end of sequence */
178 avio_wb24(pb, 0); /* Always 0 for AVC EOS. */
179 avio_wb32(pb, 16); /* Size of FLV tag */
182 static void put_amf_double(AVIOContext *pb, double d)
184 avio_w8(pb, AMF_DATA_TYPE_NUMBER);
185 avio_wb64(pb, av_double2int(d));
188 static void put_amf_bool(AVIOContext *pb, int b)
190 avio_w8(pb, AMF_DATA_TYPE_BOOL);
194 static int flv_write_header(AVFormatContext *s)
196 AVIOContext *pb = s->pb;
197 FLVContext *flv = s->priv_data;
198 AVCodecContext *audio_enc = NULL, *video_enc = NULL, *data_enc = NULL;
199 int i, metadata_count = 0;
200 double framerate = 0.0;
201 int64_t metadata_size_pos, data_size, metadata_count_pos;
202 AVDictionaryEntry *tag = NULL;
204 for (i = 0; i < s->nb_streams; i++) {
205 AVCodecContext *enc = s->streams[i]->codec;
206 FLVStreamContext *sc;
207 switch (enc->codec_type) {
208 case AVMEDIA_TYPE_VIDEO:
209 if (s->streams[i]->avg_frame_rate.den &&
210 s->streams[i]->avg_frame_rate.num) {
211 framerate = av_q2d(s->streams[i]->avg_frame_rate);
213 framerate = 1 / av_q2d(s->streams[i]->codec->time_base);
216 av_log(s, AV_LOG_ERROR,
217 "at most one video stream is supported in flv\n");
218 return AVERROR(EINVAL);
221 if (enc->codec_tag == 0) {
222 av_log(s, AV_LOG_ERROR, "Video codec '%s' for stream %d is not compatible with FLV\n",
223 avcodec_get_name(enc->codec_id), i);
224 return AVERROR(EINVAL);
227 case AVMEDIA_TYPE_AUDIO:
229 av_log(s, AV_LOG_ERROR,
230 "at most one audio stream is supported in flv\n");
231 return AVERROR(EINVAL);
234 if (get_audio_flags(s, enc) < 0)
235 return AVERROR_INVALIDDATA;
237 case AVMEDIA_TYPE_DATA:
238 if (enc->codec_id != AV_CODEC_ID_TEXT) {
239 av_log(s, AV_LOG_ERROR, "Data codec '%s' for stream %d is not compatible with FLV\n",
240 avcodec_get_name(enc->codec_id), i);
241 return AVERROR_INVALIDDATA;
246 av_log(s, AV_LOG_ERROR, "Codec type '%s' for stream %d is not compatible with FLV\n",
247 av_get_media_type_string(enc->codec_type), i);
248 return AVERROR(EINVAL);
250 avpriv_set_pts_info(s->streams[i], 32, 1, 1000); /* 32 bit pts in ms */
252 sc = av_mallocz(sizeof(FLVStreamContext));
254 return AVERROR(ENOMEM);
255 s->streams[i]->priv_data = sc;
259 flv->delay = AV_NOPTS_VALUE;
261 avio_write(pb, "FLV", 3);
263 avio_w8(pb, FLV_HEADER_FLAG_HASAUDIO * !!audio_enc +
264 FLV_HEADER_FLAG_HASVIDEO * !!video_enc);
268 for (i = 0; i < s->nb_streams; i++)
269 if (s->streams[i]->codec->codec_tag == 5) {
270 avio_w8(pb, 8); // message type
271 avio_wb24(pb, 0); // include flags
272 avio_wb24(pb, 0); // time stamp
273 avio_wb32(pb, 0); // reserved
274 avio_wb32(pb, 11); // size
279 avio_w8(pb, 18); // tag type META
280 metadata_size_pos = avio_tell(pb);
281 avio_wb24(pb, 0); // size of data part (sum of all parts below)
282 avio_wb24(pb, 0); // timestamp
283 avio_wb32(pb, 0); // reserved
285 /* now data of data_size size */
287 /* first event name as a string */
288 avio_w8(pb, AMF_DATA_TYPE_STRING);
289 put_amf_string(pb, "onMetaData"); // 12 bytes
291 /* mixed array (hash) with size and string/type/data tuples */
292 avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
293 metadata_count_pos = avio_tell(pb);
294 metadata_count = 5 * !!video_enc +
297 2; // +2 for duration and file size
299 avio_wb32(pb, metadata_count);
301 put_amf_string(pb, "duration");
302 flv->duration_offset= avio_tell(pb);
304 // fill in the guessed duration, it'll be corrected later if incorrect
305 put_amf_double(pb, s->duration / AV_TIME_BASE);
308 put_amf_string(pb, "width");
309 put_amf_double(pb, video_enc->width);
311 put_amf_string(pb, "height");
312 put_amf_double(pb, video_enc->height);
314 put_amf_string(pb, "videodatarate");
315 put_amf_double(pb, video_enc->bit_rate / 1024.0);
317 put_amf_string(pb, "framerate");
318 put_amf_double(pb, framerate);
320 put_amf_string(pb, "videocodecid");
321 put_amf_double(pb, video_enc->codec_tag);
325 put_amf_string(pb, "audiodatarate");
326 put_amf_double(pb, audio_enc->bit_rate / 1024.0);
328 put_amf_string(pb, "audiosamplerate");
329 put_amf_double(pb, audio_enc->sample_rate);
331 put_amf_string(pb, "audiosamplesize");
332 put_amf_double(pb, audio_enc->codec_id == AV_CODEC_ID_PCM_U8 ? 8 : 16);
334 put_amf_string(pb, "stereo");
335 put_amf_bool(pb, audio_enc->channels == 2);
337 put_amf_string(pb, "audiocodecid");
338 put_amf_double(pb, audio_enc->codec_tag);
342 put_amf_string(pb, "datastream");
343 put_amf_double(pb, 0.0);
346 while ((tag = av_dict_get(s->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
347 if( !strcmp(tag->key, "width")
348 ||!strcmp(tag->key, "height")
349 ||!strcmp(tag->key, "videodatarate")
350 ||!strcmp(tag->key, "framerate")
351 ||!strcmp(tag->key, "videocodecid")
352 ||!strcmp(tag->key, "audiodatarate")
353 ||!strcmp(tag->key, "audiosamplerate")
354 ||!strcmp(tag->key, "audiosamplesize")
355 ||!strcmp(tag->key, "stereo")
356 ||!strcmp(tag->key, "audiocodecid")
357 ||!strcmp(tag->key, "duration")
358 ||!strcmp(tag->key, "onMetaData")
360 av_log(s, AV_LOG_DEBUG, "Ignoring metadata for %s\n", tag->key);
363 put_amf_string(pb, tag->key);
364 avio_w8(pb, AMF_DATA_TYPE_STRING);
365 put_amf_string(pb, tag->value);
369 put_amf_string(pb, "filesize");
370 flv->filesize_offset = avio_tell(pb);
371 put_amf_double(pb, 0); // delayed write
373 put_amf_string(pb, "");
374 avio_w8(pb, AMF_END_OF_OBJECT);
376 /* write total size of tag */
377 data_size = avio_tell(pb) - metadata_size_pos - 10;
379 avio_seek(pb, metadata_count_pos, SEEK_SET);
380 avio_wb32(pb, metadata_count);
382 avio_seek(pb, metadata_size_pos, SEEK_SET);
383 avio_wb24(pb, data_size);
384 avio_skip(pb, data_size + 10 - 3);
385 avio_wb32(pb, data_size + 11);
387 for (i = 0; i < s->nb_streams; i++) {
388 AVCodecContext *enc = s->streams[i]->codec;
389 if (enc->codec_id == AV_CODEC_ID_AAC || enc->codec_id == AV_CODEC_ID_H264 || enc->codec_id == AV_CODEC_ID_MPEG4) {
391 avio_w8(pb, enc->codec_type == AVMEDIA_TYPE_VIDEO ?
392 FLV_TAG_TYPE_VIDEO : FLV_TAG_TYPE_AUDIO);
393 avio_wb24(pb, 0); // size patched later
394 avio_wb24(pb, 0); // ts
395 avio_w8(pb, 0); // ts ext
396 avio_wb24(pb, 0); // streamid
398 if (enc->codec_id == AV_CODEC_ID_AAC) {
399 avio_w8(pb, get_audio_flags(s, enc));
400 avio_w8(pb, 0); // AAC sequence header
401 avio_write(pb, enc->extradata, enc->extradata_size);
403 avio_w8(pb, enc->codec_tag | FLV_FRAME_KEY); // flags
404 avio_w8(pb, 0); // AVC sequence header
405 avio_wb24(pb, 0); // composition time
406 ff_isom_write_avcc(pb, enc->extradata, enc->extradata_size);
408 data_size = avio_tell(pb) - pos;
409 avio_seek(pb, -data_size - 10, SEEK_CUR);
410 avio_wb24(pb, data_size);
411 avio_skip(pb, data_size + 10 - 3);
412 avio_wb32(pb, data_size + 11); // previous tag size
419 static int flv_write_trailer(AVFormatContext *s)
423 AVIOContext *pb = s->pb;
424 FLVContext *flv = s->priv_data;
428 for (i = 0; i < s->nb_streams; i++) {
429 AVCodecContext *enc = s->streams[i]->codec;
430 FLVStreamContext *sc = s->streams[i]->priv_data;
431 if (enc->codec_type == AVMEDIA_TYPE_VIDEO &&
432 (enc->codec_id == AV_CODEC_ID_H264 || enc->codec_id == AV_CODEC_ID_MPEG4))
433 put_avc_eos_tag(pb, sc->last_ts);
436 file_size = avio_tell(pb);
438 /* update information */
439 if (avio_seek(pb, flv->duration_offset, SEEK_SET) < 0)
440 av_log(s, AV_LOG_WARNING, "Failed to update header with correct duration.\n");
442 put_amf_double(pb, flv->duration / (double)1000);
443 if (avio_seek(pb, flv->filesize_offset, SEEK_SET) < 0)
444 av_log(s, AV_LOG_WARNING, "Failed to update header with correct filesize.\n");
446 put_amf_double(pb, file_size);
448 avio_seek(pb, file_size, SEEK_SET);
452 static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
454 AVIOContext *pb = s->pb;
455 AVCodecContext *enc = s->streams[pkt->stream_index]->codec;
456 FLVContext *flv = s->priv_data;
457 FLVStreamContext *sc = s->streams[pkt->stream_index]->priv_data;
459 int size = pkt->size;
460 uint8_t *data = NULL;
461 int flags = -1, flags_size, ret;
463 if (enc->codec_id == AV_CODEC_ID_VP6F || enc->codec_id == AV_CODEC_ID_VP6A ||
464 enc->codec_id == AV_CODEC_ID_VP6 || enc->codec_id == AV_CODEC_ID_AAC)
466 else if (enc->codec_id == AV_CODEC_ID_H264 || enc->codec_id == AV_CODEC_ID_MPEG4)
471 switch (enc->codec_type) {
472 case AVMEDIA_TYPE_VIDEO:
473 avio_w8(pb, FLV_TAG_TYPE_VIDEO);
475 flags = enc->codec_tag;
477 av_log(s, AV_LOG_ERROR,
478 "Video codec '%s' is not compatible with FLV\n",
479 avcodec_get_name(enc->codec_id));
480 return AVERROR(EINVAL);
483 flags |= pkt->flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER;
485 case AVMEDIA_TYPE_AUDIO:
486 flags = get_audio_flags(s, enc);
490 avio_w8(pb, FLV_TAG_TYPE_AUDIO);
492 case AVMEDIA_TYPE_DATA:
493 avio_w8(pb, FLV_TAG_TYPE_META);
496 return AVERROR(EINVAL);
499 if (enc->codec_id == AV_CODEC_ID_H264 || enc->codec_id == AV_CODEC_ID_MPEG4) {
500 /* check if extradata looks like mp4 formated */
501 if (enc->extradata_size > 0 && *(uint8_t*)enc->extradata != 1)
502 if ((ret = ff_avc_parse_nal_units_buf(pkt->data, &data, &size)) < 0)
504 } else if (enc->codec_id == AV_CODEC_ID_AAC && pkt->size > 2 &&
505 (AV_RB16(pkt->data) & 0xfff0) == 0xfff0) {
506 if (!s->streams[pkt->stream_index]->nb_frames) {
507 av_log(s, AV_LOG_ERROR, "Malformed AAC bitstream detected: "
508 "use audio bitstream filter 'aac_adtstoasc' to fix it "
509 "('-bsf:a aac_adtstoasc' option with ffmpeg)\n");
510 return AVERROR_INVALIDDATA;
512 av_log(s, AV_LOG_WARNING, "aac bitstream error\n");
515 if (flv->delay == AV_NOPTS_VALUE)
516 flv->delay = -pkt->dts;
518 if (pkt->dts < -flv->delay) {
519 av_log(s, AV_LOG_WARNING,
520 "Packets are not in the proper order with respect to DTS\n");
521 return AVERROR(EINVAL);
524 ts = pkt->dts + flv->delay; // add delay to force positive dts
526 /* check Speex packet duration */
527 if (enc->codec_id == AV_CODEC_ID_SPEEX && ts - sc->last_ts > 160)
528 av_log(s, AV_LOG_WARNING, "Warning: Speex stream has more than "
529 "8 frames per packet. Adobe Flash "
530 "Player cannot handle this!\n");
532 if (sc->last_ts < ts)
535 avio_wb24(pb, size + flags_size);
537 avio_w8(pb, (ts >> 24) & 0x7F); // timestamps are 32 bits _signed_
538 avio_wb24(pb, flv->reserved);
540 if (enc->codec_type == AVMEDIA_TYPE_DATA) {
542 int64_t metadata_size_pos = avio_tell(pb);
543 avio_w8(pb, AMF_DATA_TYPE_STRING);
544 put_amf_string(pb, "onTextData");
545 avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
547 put_amf_string(pb, "type");
548 avio_w8(pb, AMF_DATA_TYPE_STRING);
549 put_amf_string(pb, "Text");
550 put_amf_string(pb, "text");
551 avio_w8(pb, AMF_DATA_TYPE_STRING);
552 put_amf_string(pb, pkt->data);
553 put_amf_string(pb, "");
554 avio_w8(pb, AMF_END_OF_OBJECT);
555 /* write total size of tag */
556 data_size = avio_tell(pb) - metadata_size_pos;
557 avio_seek(pb, metadata_size_pos - 10, SEEK_SET);
558 avio_wb24(pb, data_size);
559 avio_seek(pb, data_size + 10 - 3, SEEK_CUR);
560 avio_wb32(pb, data_size + 11);
562 av_assert1(flags>=0);
564 if (enc->codec_id == AV_CODEC_ID_VP6)
566 if (enc->codec_id == AV_CODEC_ID_VP6F || enc->codec_id == AV_CODEC_ID_VP6A) {
567 if (enc->extradata_size)
568 avio_w8(pb, enc->extradata[0]);
570 avio_w8(pb, ((FFALIGN(enc->width, 16) - enc->width) << 4) |
571 (FFALIGN(enc->height, 16) - enc->height));
572 } else if (enc->codec_id == AV_CODEC_ID_AAC)
573 avio_w8(pb, 1); // AAC raw
574 else if (enc->codec_id == AV_CODEC_ID_H264 || enc->codec_id == AV_CODEC_ID_MPEG4) {
575 avio_w8(pb, 1); // AVC NALU
576 avio_wb24(pb, pkt->pts - pkt->dts);
579 avio_write(pb, data ? data : pkt->data, size);
581 avio_wb32(pb, size + flags_size + 11); // previous tag size
582 flv->duration = FFMAX(flv->duration,
583 pkt->pts + flv->delay + pkt->duration);
591 AVOutputFormat ff_flv_muxer = {
593 .long_name = NULL_IF_CONFIG_SMALL("FLV (Flash Video)"),
594 .mime_type = "video/x-flv",
596 .priv_data_size = sizeof(FLVContext),
597 .audio_codec = CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_ADPCM_SWF,
598 .video_codec = AV_CODEC_ID_FLV1,
599 .write_header = flv_write_header,
600 .write_packet = flv_write_packet,
601 .write_trailer = flv_write_trailer,
602 .codec_tag = (const AVCodecTag* const []) {
603 flv_video_codec_ids, flv_audio_codec_ids, 0
605 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |