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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avformat.h"
#undef NDEBUG
#include <assert.h>
typedef struct FLVContext {
int hasAudio;
int hasVideo;
int reserved;
} FLVContext;
static void put_be24(ByteIOContext *pb, int value)
{
put_byte(pb, (value>>16) & 0xFF );
put_byte(pb, (value>> 8) & 0xFF );
put_byte(pb, (value>> 0) & 0xFF );
}
static int get_audio_flags(AVCodecContext *enc){
int flags = 0x02;
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:
return -1;
}
if (enc->channels > 1) {
flags |= 0x01;
}
switch(enc->codec_id){
case CODEC_ID_MP3:
flags |= 0x20;
break;
case 0:
flags |= enc->codec_tag<<4;
break;
default:
return -1;
}
return flags;
}
static int flv_write_header(AVFormatContext *s)
{
ByteIOContext *pb = &s->pb;
FLVContext *flv = s->priv_data;
int i;
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;
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;
}
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);
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
flv->hasVideo = 1;
} else {
assert(enc->codec_type == CODEC_TYPE_AUDIO);
flags = get_audio_flags(enc);
assert(size);
put_byte(pb, 8);
// We got audio! Make sure we set this to the global flags on closure
flv->hasAudio = 1;
}
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); // reserved
put_flush_packet(pb);
return 0;
}
static AVOutputFormat flv_oformat = {
"flv",
"flv format",
"video/x-flashvideo",
"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,
};
int flvenc_init(void)
{
av_register_output_format(&flv_oformat);
return 0;
}