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/*
* Ogg bitstream support
* Mark Hills <mark@pogo.org.uk>
*
* Uses libogg, but requires libvorbisenc to construct correct headers
* when containing Vorbis stream -- currently the only format supported
*/
#include <stdio.h>
#include <time.h>
#include <ogg/ogg.h>
#include <vorbis/vorbisenc.h>
#include "avformat.h"
#include "oggvorbis.h"
typedef struct OggContext {
ogg_stream_state os ;
int header_written ;
ogg_int64_t base_packet_no ;
ogg_int64_t base_granule_pos ;
} OggContext ;
static int ogg_write_header(AVFormatContext *avfcontext) {
OggContext *context ;
AVCodecContext *avccontext ;
vorbis_info vi ;
vorbis_dsp_state vd ;
vorbis_comment vc ;
vorbis_block vb ;
ogg_packet header, header_comm, header_code ;
int n ;
fprintf(stderr, "ogg_write_header\n") ;
if(!(context = malloc(sizeof(OggContext))))
return -1 ;
avfcontext->priv_data = context ;
srand(time(NULL));
ogg_stream_init(&context->os, rand());
for(n = 0 ; n < avfcontext->nb_streams ; n++) {
avccontext = &avfcontext->streams[n]->codec ;
/* begin vorbis specific code */
vorbis_info_init(&vi) ;
/* code copied from libavcodec/oggvorbis.c */
if(oggvorbis_init_encoder(&vi, avccontext) < 0) {
fprintf(stderr, "ogg_write_header: init_encoder failed") ;
return -1 ;
}
vorbis_analysis_init(&vd, &vi) ;
vorbis_block_init(&vd, &vb) ;
vorbis_comment_init(&vc) ;
vorbis_comment_add_tag(&vc, "encoder", "ffmpeg") ;
if(*avfcontext->title)
vorbis_comment_add_tag(&vc, "title", avfcontext->title) ;
vorbis_analysis_headerout(&vd, &vc, &header,
&header_comm, &header_code) ;
ogg_stream_packetin(&context->os, &header) ;
ogg_stream_packetin(&context->os, &header_comm) ;
ogg_stream_packetin(&context->os, &header_code) ;
vorbis_comment_clear(&vc) ;
/* end of vorbis specific code */
context->header_written = 0 ;
context->base_packet_no = 0 ;
}
return 0 ;
}
static int ogg_write_packet(AVFormatContext *avfcontext,
int stream_index,
unsigned char *buf, int size, int force_pts)
{
OggContext *context = avfcontext->priv_data ;
ogg_packet *op ;
ogg_page og ;
int l = 0 ;
/* flush header packets so audio starts on a new page */
if(!context->header_written) {
while(ogg_stream_flush(&context->os, &og)) {
put_buffer(&avfcontext->pb, og.header, og.header_len) ;
put_buffer(&avfcontext->pb, og.body, og.body_len) ;
put_flush_packet(&avfcontext->pb);
}
context->header_written = 1 ;
}
while(l < size) {
op = (ogg_packet*)(buf + l) ;
op->packet = buf + l + sizeof(ogg_packet) ; /* fix data pointer */
if(!context->base_packet_no) { /* this is the first packet */
context->base_packet_no = op->packetno ;
context->base_granule_pos = op->granulepos ;
}
/* correct the fields in the packet -- essential for streaming */
op->packetno -= context->base_packet_no ;
op->granulepos -= context->base_granule_pos ;
ogg_stream_packetin(&context->os, op) ;
l += sizeof(ogg_packet) + op->bytes ;
while(ogg_stream_pageout(&context->os, &og)) {
put_buffer(&avfcontext->pb, og.header, og.header_len) ;
put_buffer(&avfcontext->pb, og.body, og.body_len) ;
put_flush_packet(&avfcontext->pb);
}
}
return 0;
}
static int ogg_write_trailer(AVFormatContext *avfcontext) {
OggContext *context = avfcontext->priv_data ;
ogg_page og ;
fprintf(stderr, "ogg_write_trailer\n") ;
while(ogg_stream_flush(&context->os, &og)) {
put_buffer(&avfcontext->pb, og.header, og.header_len) ;
put_buffer(&avfcontext->pb, og.body, og.body_len) ;
put_flush_packet(&avfcontext->pb);
}
ogg_stream_clear(&context->os) ;
return 0 ;
}
AVOutputFormat ogg_oformat = {
"ogg",
"Ogg Vorbis",
"audio/x-vorbis",
"ogg",
sizeof(OggContext),
CODEC_ID_VORBIS,
0,
ogg_write_header,
ogg_write_packet,
ogg_write_trailer,
};
int ogg_init(void) {
av_register_output_format(&ogg_oformat) ;
return 0 ;
}
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