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252 lines
8.7 KiB
C
252 lines
8.7 KiB
C
/********************************************************************
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* *
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* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
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* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
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* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
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* *
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* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007 *
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* by the Xiph.Org Foundation http://www.xiph.org/ *
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* *
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********************************************************************
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function: simple example encoder
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last mod: $Id: encoder_example.c 16946 2010-03-03 16:12:40Z xiphmont $
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********************************************************************/
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/* takes a stereo 16bit 44.1kHz WAV file from stdin and encodes it into
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a Vorbis bitstream */
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/* Note that this is POSIX, not ANSI, code */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <math.h>
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#include <vorbis/vorbisenc.h>
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#ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */
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#include <io.h>
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#include <fcntl.h>
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#endif
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#if defined(__MACOS__) && defined(__MWERKS__)
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#include <console.h> /* CodeWarrior's Mac "command-line" support */
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#endif
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#define READ 1024
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signed char readbuffer[READ*4+44]; /* out of the data segment, not the stack */
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int main(){
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ogg_stream_state os; /* take physical pages, weld into a logical
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stream of packets */
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ogg_page og; /* one Ogg bitstream page. Vorbis packets are inside */
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ogg_packet op; /* one raw packet of data for decode */
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vorbis_info vi; /* struct that stores all the static vorbis bitstream
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settings */
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vorbis_comment vc; /* struct that stores all the user comments */
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vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */
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vorbis_block vb; /* local working space for packet->PCM decode */
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int eos=0,ret;
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int i, founddata;
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#if defined(macintosh) && defined(__MWERKS__)
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int argc = 0;
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char **argv = NULL;
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argc = ccommand(&argv); /* get a "command line" from the Mac user */
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/* this also lets the user set stdin and stdout */
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#endif
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/* we cheat on the WAV header; we just bypass 44 bytes (simplest WAV
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header is 44 bytes) and assume that the data is 44.1khz, stereo, 16 bit
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little endian pcm samples. This is just an example, after all. */
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#ifdef _WIN32 /* We need to set stdin/stdout to binary mode. Damn windows. */
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/* if we were reading/writing a file, it would also need to in
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binary mode, eg, fopen("file.wav","wb"); */
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/* Beware the evil ifdef. We avoid these where we can, but this one we
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cannot. Don't add any more, you'll probably go to hell if you do. */
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_setmode( _fileno( stdin ), _O_BINARY );
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_setmode( _fileno( stdout ), _O_BINARY );
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#endif
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/* we cheat on the WAV header; we just bypass the header and never
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verify that it matches 16bit/stereo/44.1kHz. This is just an
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example, after all. */
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readbuffer[0] = '\0';
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for (i=0, founddata=0; i<30 && ! feof(stdin) && ! ferror(stdin); i++)
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{
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fread(readbuffer,1,2,stdin);
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if ( ! strncmp((char*)readbuffer, "da", 2) ){
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founddata = 1;
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fread(readbuffer,1,6,stdin);
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break;
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}
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}
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/********** Encode setup ************/
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vorbis_info_init(&vi);
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/* choose an encoding mode. A few possibilities commented out, one
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actually used: */
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/*********************************************************************
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Encoding using a VBR quality mode. The usable range is -.1
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(lowest quality, smallest file) to 1. (highest quality, largest file).
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Example quality mode .4: 44kHz stereo coupled, roughly 128kbps VBR
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ret = vorbis_encode_init_vbr(&vi,2,44100,.4);
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---------------------------------------------------------------------
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Encoding using an average bitrate mode (ABR).
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example: 44kHz stereo coupled, average 128kbps VBR
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ret = vorbis_encode_init(&vi,2,44100,-1,128000,-1);
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---------------------------------------------------------------------
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Encode using a quality mode, but select that quality mode by asking for
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an approximate bitrate. This is not ABR, it is true VBR, but selected
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using the bitrate interface, and then turning bitrate management off:
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ret = ( vorbis_encode_setup_managed(&vi,2,44100,-1,128000,-1) ||
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vorbis_encode_ctl(&vi,OV_ECTL_RATEMANAGE2_SET,NULL) ||
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vorbis_encode_setup_init(&vi));
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*********************************************************************/
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ret=vorbis_encode_init_vbr(&vi,2,44100,0.1);
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/* do not continue if setup failed; this can happen if we ask for a
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mode that libVorbis does not support (eg, too low a bitrate, etc,
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will return 'OV_EIMPL') */
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if(ret)exit(1);
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/* add a comment */
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vorbis_comment_init(&vc);
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vorbis_comment_add_tag(&vc,"ENCODER","encoder_example.c");
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/* set up the analysis state and auxiliary encoding storage */
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vorbis_analysis_init(&vd,&vi);
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vorbis_block_init(&vd,&vb);
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/* set up our packet->stream encoder */
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/* pick a random serial number; that way we can more likely build
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chained streams just by concatenation */
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srand(time(NULL));
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ogg_stream_init(&os,rand());
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/* Vorbis streams begin with three headers; the initial header (with
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most of the codec setup parameters) which is mandated by the Ogg
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bitstream spec. The second header holds any comment fields. The
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third header holds the bitstream codebook. We merely need to
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make the headers, then pass them to libvorbis one at a time;
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libvorbis handles the additional Ogg bitstream constraints */
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{
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ogg_packet header;
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ogg_packet header_comm;
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ogg_packet header_code;
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vorbis_analysis_headerout(&vd,&vc,&header,&header_comm,&header_code);
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ogg_stream_packetin(&os,&header); /* automatically placed in its own
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page */
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ogg_stream_packetin(&os,&header_comm);
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ogg_stream_packetin(&os,&header_code);
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/* This ensures the actual
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* audio data will start on a new page, as per spec
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*/
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while(!eos){
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int result=ogg_stream_flush(&os,&og);
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if(result==0)break;
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fwrite(og.header,1,og.header_len,stdout);
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fwrite(og.body,1,og.body_len,stdout);
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}
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}
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while(!eos){
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long i;
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long bytes=fread(readbuffer,1,READ*4,stdin); /* stereo hardwired here */
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if(bytes==0){
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/* end of file. this can be done implicitly in the mainline,
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but it's easier to see here in non-clever fashion.
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Tell the library we're at end of stream so that it can handle
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the last frame and mark end of stream in the output properly */
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vorbis_analysis_wrote(&vd,0);
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}else{
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/* data to encode */
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/* expose the buffer to submit data */
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float **buffer=vorbis_analysis_buffer(&vd,READ);
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/* uninterleave samples */
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for(i=0;i<bytes/4;i++){
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buffer[0][i]=((readbuffer[i*4+1]<<8)|
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(0x00ff&(int)readbuffer[i*4]))/32768.f;
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buffer[1][i]=((readbuffer[i*4+3]<<8)|
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(0x00ff&(int)readbuffer[i*4+2]))/32768.f;
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}
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/* tell the library how much we actually submitted */
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vorbis_analysis_wrote(&vd,i);
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}
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/* vorbis does some data preanalysis, then divvies up blocks for
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more involved (potentially parallel) processing. Get a single
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block for encoding now */
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while(vorbis_analysis_blockout(&vd,&vb)==1){
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/* analysis, assume we want to use bitrate management */
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vorbis_analysis(&vb,NULL);
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vorbis_bitrate_addblock(&vb);
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while(vorbis_bitrate_flushpacket(&vd,&op)){
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/* weld the packet into the bitstream */
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ogg_stream_packetin(&os,&op);
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/* write out pages (if any) */
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while(!eos){
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int result=ogg_stream_pageout(&os,&og);
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if(result==0)break;
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fwrite(og.header,1,og.header_len,stdout);
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fwrite(og.body,1,og.body_len,stdout);
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/* this could be set above, but for illustrative purposes, I do
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it here (to show that vorbis does know where the stream ends) */
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if(ogg_page_eos(&og))eos=1;
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}
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}
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}
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}
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/* clean up and exit. vorbis_info_clear() must be called last */
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ogg_stream_clear(&os);
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vorbis_block_clear(&vb);
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vorbis_dsp_clear(&vd);
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vorbis_comment_clear(&vc);
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vorbis_info_clear(&vi);
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/* ogg_page and ogg_packet structs always point to storage in
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libvorbis. They're never freed or manipulated directly */
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fprintf(stderr,"Done.\n");
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return(0);
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}
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