ffmpeg/libavformat/flvenc.c

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/*
* FLV encoder.
* Copyright (c) 2003 The FFmpeg Project.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#undef NDEBUG
#include <assert.h>
typedef struct FLVContext {
int hasAudio;
int hasVideo;
int reserved;
offset_t duration_offset;
offset_t filesize_offset;
int64_t duration;
} FLVContext;
static int get_audio_flags(AVCodecContext *enc){
int flags = (enc->bits_per_sample == 16) ? 0x2 : 0x0;
switch (enc->sample_rate) {
case 44100:
flags |= 0x0C;
break;
case 22050:
flags |= 0x08;
break;
case 11025:
flags |= 0x04;
break;
case 8000: //nellymoser only
case 5512: //not mp3
flags |= 0x00;
break;
default:
av_log(enc, AV_LOG_ERROR, "flv doesnt support that sample rate, choose from (44100, 22050, 11025)\n");
return -1;
}
if (enc->channels > 1) {
flags |= 0x01;
}
switch(enc->codec_id){
case CODEC_ID_MP3:
flags |= 0x20 | 0x2;
break;
case CODEC_ID_PCM_S8:
break;
case CODEC_ID_PCM_S16BE:
flags |= 0x60 | 0x2;
break;
case CODEC_ID_PCM_S16LE:
flags |= 0x2;
break;
case CODEC_ID_ADPCM_SWF:
flags |= 0x10;
break;
case 0:
flags |= enc->codec_tag<<4;
break;
default:
av_log(enc, AV_LOG_ERROR, "codec not compatible with flv\n");
return -1;
}
return flags;
}
#define AMF_DOUBLE 0
#define AMF_BOOLEAN 1
#define AMF_STRING 2
#define AMF_OBJECT 3
#define AMF_MIXED_ARRAY 8
#define AMF_ARRAY 10
#define AMF_DATE 11
static void put_amf_string(ByteIOContext *pb, const char *str)
{
size_t len = strlen(str);
put_be16(pb, len);
put_buffer(pb, str, len);
}
static void put_amf_double(ByteIOContext *pb, double d)
{
put_byte(pb, AMF_DOUBLE);
put_be64(pb, av_dbl2int(d));
}
static int flv_write_header(AVFormatContext *s)
{
ByteIOContext *pb = &s->pb;
FLVContext *flv = s->priv_data;
int i, width, height, samplerate;
double framerate = 0.0;
int metadata_size_pos, data_size;
flv->hasAudio = 0;
flv->hasVideo = 0;
put_tag(pb,"FLV");
put_byte(pb,1);
put_byte(pb,0); // delayed write
put_be32(pb,9);
put_be32(pb,0);
for(i=0; i<s->nb_streams; i++){
AVCodecContext *enc = s->streams[i]->codec;
if (enc->codec_type == CODEC_TYPE_VIDEO) {
width = enc->width;
height = enc->height;
if (s->streams[i]->r_frame_rate.den && s->streams[i]->r_frame_rate.num) {
framerate = av_q2d(s->streams[i]->r_frame_rate);
} else {
framerate = 1/av_q2d(s->streams[i]->codec->time_base);
}
flv->hasVideo=1;
} else {
flv->hasAudio=1;
samplerate = enc->sample_rate;
}
av_set_pts_info(s->streams[i], 24, 1, 1000); /* 24 bit pts in ms */
if(enc->codec_tag == 5){
put_byte(pb,8); // message type
put_be24(pb,0); // include flags
put_be24(pb,0); // time stamp
put_be32(pb,0); // reserved
put_be32(pb,11); // size
flv->reserved=5;
}
if(enc->codec_type == CODEC_TYPE_AUDIO && get_audio_flags(enc)<0)
return -1;
}
/* write meta_tag */
put_byte(pb, 18); // tag type META
metadata_size_pos= url_ftell(pb);
put_be24(pb, 0); // size of data part (sum of all parts below)
put_be24(pb, 0); // time stamp
put_be32(pb, 0); // reserved
/* now data of data_size size */
/* first event name as a string */
put_byte(pb, AMF_STRING); // 1 byte
put_amf_string(pb, "onMetaData"); // 12 bytes
/* mixed array (hash) with size and string/type/data tuples */
put_byte(pb, AMF_MIXED_ARRAY);
put_be32(pb, 4*flv->hasVideo + flv->hasAudio + 2); // +2 for duration and file size
put_amf_string(pb, "duration");
flv->duration_offset= url_ftell(pb);
put_amf_double(pb, 0); // delayed write
if(flv->hasVideo){
put_amf_string(pb, "width");
put_amf_double(pb, width);
put_amf_string(pb, "height");
put_amf_double(pb, height);
put_amf_string(pb, "videodatarate");
put_amf_double(pb, s->bit_rate / 1024.0);
put_amf_string(pb, "framerate");
put_amf_double(pb, framerate);
}
if(flv->hasAudio){
put_amf_string(pb, "audiosamplerate");
put_amf_double(pb, samplerate);
}
put_amf_string(pb, "filesize");
flv->filesize_offset= url_ftell(pb);
put_amf_double(pb, 0); // delayed write
put_amf_string(pb, "");
put_byte(pb, 9); // end marker 1 byte
/* write total size of tag */
data_size= url_ftell(pb) - metadata_size_pos - 10;
url_fseek(pb, metadata_size_pos, SEEK_SET);
put_be24(pb, data_size);
url_fseek(pb, data_size + 10 - 3, SEEK_CUR);
put_be32(pb, data_size + 11);
return 0;
}
static int flv_write_trailer(AVFormatContext *s)
{
int64_t file_size;
int flags = 0;
ByteIOContext *pb = &s->pb;
FLVContext *flv = s->priv_data;
file_size = url_ftell(pb);
flags |= flv->hasAudio ? 4 : 0;
flags |= flv->hasVideo ? 1 : 0;
url_fseek(pb, 4, SEEK_SET);
put_byte(pb,flags);
/* update informations */
url_fseek(pb, flv->duration_offset, SEEK_SET);
put_amf_double(pb, flv->duration / (double)1000);
url_fseek(pb, flv->filesize_offset, SEEK_SET);
put_amf_double(pb, file_size);
url_fseek(pb, file_size, SEEK_SET);
return 0;
}
static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
{
ByteIOContext *pb = &s->pb;
AVCodecContext *enc = s->streams[pkt->stream_index]->codec;
FLVContext *flv = s->priv_data;
int size= pkt->size;
int flags;
// av_log(s, AV_LOG_DEBUG, "type:%d pts: %lld size:%d\n", enc->codec_type, timestamp, size);
if (enc->codec_type == CODEC_TYPE_VIDEO) {
put_byte(pb, 9);
flags = 2; // choose h263
flags |= pkt->flags & PKT_FLAG_KEY ? 0x10 : 0x20; // add keyframe indicator
} else {
assert(enc->codec_type == CODEC_TYPE_AUDIO);
flags = get_audio_flags(enc);
assert(size);
put_byte(pb, 8);
}
put_be24(pb,size+1); // include flags
put_be24(pb,pkt->pts);
put_be32(pb,flv->reserved);
put_byte(pb,flags);
put_buffer(pb, pkt->data, size);
put_be32(pb,size+1+11); // previous tag size
flv->duration = pkt->pts + pkt->duration;
put_flush_packet(pb);
return 0;
}
AVOutputFormat flv_muxer = {
"flv",
"flv format",
"video/x-flv",
"flv",
sizeof(FLVContext),
#ifdef CONFIG_MP3LAME
CODEC_ID_MP3,
#else // CONFIG_MP3LAME
CODEC_ID_NONE,
#endif // CONFIG_MP3LAME
CODEC_ID_FLV1,
flv_write_header,
flv_write_packet,
flv_write_trailer,
};