ffmpeg/libavformat/ogg.c

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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"
#define DECODER_BUFFER_SIZE 4096
typedef struct OggContext {
/* output */
ogg_stream_state os ;
int header_handled ;
ogg_int64_t base_packet_no ;
ogg_int64_t base_granule_pos ;
/* input */
ogg_sync_state oy ;
} OggContext ;
#ifdef CONFIG_ENCODERS
static int ogg_write_header(AVFormatContext *avfcontext)
{
OggContext *context = avfcontext->priv_data;
AVCodecContext *avccontext ;
vorbis_info vi ;
vorbis_dsp_state vd ;
vorbis_comment vc ;
vorbis_block vb ;
ogg_packet header, header_comm, header_code ;
int n ;
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", LIBAVFORMAT_IDENT) ;
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_block_clear(&vb) ;
vorbis_dsp_clear(&vd) ;
vorbis_info_clear(&vi) ;
vorbis_comment_clear(&vc) ;
/* end of vorbis specific code */
context->header_handled = 0 ;
context->base_packet_no = 0 ;
}
return 0 ;
}
static int ogg_write_packet(AVFormatContext *avfcontext,
int stream_index,
const uint8_t *buf, int size, int64_t 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_handled) {
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_handled = 1 ;
}
while(l < size) {
op = (ogg_packet*)(buf + l) ;
op->packet = (uint8_t*) 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 ;
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 ;
}
static 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,
} ;
#endif //CONFIG_ENCODERS
static int next_packet(AVFormatContext *avfcontext, ogg_packet *op) {
OggContext *context = avfcontext->priv_data ;
ogg_page og ;
char *buf ;
while(ogg_stream_packetout(&context->os, op) != 1) {
/* while no pages are available, read in more data to the sync */
while(ogg_sync_pageout(&context->oy, &og) != 1) {
buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;
if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)
return 1 ;
ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ;
}
/* got a page. Feed it into the stream and get the packet */
if(ogg_stream_pagein(&context->os, &og) != 0)
return 1 ;
}
return 0 ;
}
static int ogg_read_header(AVFormatContext *avfcontext, AVFormatParameters *ap)
{
OggContext *context = avfcontext->priv_data;
char *buf ;
ogg_page og ;
AVStream *ast ;
ogg_sync_init(&context->oy) ;
buf = ogg_sync_buffer(&context->oy, DECODER_BUFFER_SIZE) ;
if(get_buffer(&avfcontext->pb, buf, DECODER_BUFFER_SIZE) <= 0)
return -EIO ;
ogg_sync_wrote(&context->oy, DECODER_BUFFER_SIZE) ;
ogg_sync_pageout(&context->oy, &og) ;
ogg_stream_init(&context->os, ogg_page_serialno(&og)) ;
ogg_stream_pagein(&context->os, &og) ;
/* currently only one vorbis stream supported */
ast = av_new_stream(avfcontext, 0) ;
if(!ast)
return AVERROR_NOMEM ;
ast->codec.codec_type = CODEC_TYPE_AUDIO ;
ast->codec.codec_id = CODEC_ID_VORBIS ;
return 0 ;
}
static int ogg_read_packet(AVFormatContext *avfcontext, AVPacket *pkt) {
ogg_packet op ;
if(next_packet(avfcontext, &op))
return -EIO ;
if(av_new_packet(pkt, sizeof(ogg_packet) + op.bytes) < 0)
return -EIO ;
pkt->stream_index = 0 ;
memcpy(pkt->data, &op, sizeof(ogg_packet)) ;
memcpy(pkt->data + sizeof(ogg_packet), op.packet, op.bytes) ;
return sizeof(ogg_packet) + op.bytes ;
}
static int ogg_read_close(AVFormatContext *avfcontext) {
OggContext *context = avfcontext->priv_data ;
ogg_stream_clear(&context->os) ;
ogg_sync_clear(&context->oy) ;
return 0 ;
}
static AVInputFormat ogg_iformat = {
"ogg",
"Ogg Vorbis",
sizeof(OggContext),
NULL,
ogg_read_header,
ogg_read_packet,
ogg_read_close,
.extensions = "ogg",
} ;
int ogg_init(void) {
#ifdef CONFIG_ENCODERS
av_register_output_format(&ogg_oformat) ;
#endif
av_register_input_format(&ogg_iformat);
return 0 ;
}