release/src/router/libvorbis/examples/encoder_example.c

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007             *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: simple example encoder
  14  last mod: $Id: encoder_example.c 16037 2009-05-26 21:10:58Z xiphmont $
  15
  16  ********************************************************************/
  17
  18 /* takes a stereo 16bit 44.1kHz WAV file from stdin and encodes it into
  19    a Vorbis bitstream */
  20
  21 /* Note that this is POSIX, not ANSI, code */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <time.h>
  27 #include <math.h>
  28 #include <vorbis/vorbisenc.h>
  29
  30 #ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */
  31 #include <io.h>
  32 #include <fcntl.h>
  33 #endif
  34
  35 #if defined(__MACOS__) && defined(__MWERKS__)
  36 #include <console.h>      /* CodeWarrior's Mac "command-line" support */
  37 #endif
  38
  39 #define READ 1024
  40 signed char readbuffer[READ*4+44]; /* out of the data segment, not the stack */
  41
  42 int main(){
  43   ogg_stream_state os; /* take physical pages, weld into a logical
  44                           stream of packets */
  45   ogg_page         og; /* one Ogg bitstream page.  Vorbis packets are inside */
  46   ogg_packet       op; /* one raw packet of data for decode */
  47
  48   vorbis_info      vi; /* struct that stores all the static vorbis bitstream
  49                           settings */
  50   vorbis_comment   vc; /* struct that stores all the user comments */
  51
  52   vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */
  53   vorbis_block     vb; /* local working space for packet->PCM decode */
  54
  55   int eos=0,ret;
  56   int i, founddata;
  57
  58 #if defined(macintosh) && defined(__MWERKS__)
  59   int argc = 0;
  60   char **argv = NULL;
  61   argc = ccommand(&argv); /* get a "command line" from the Mac user */
  62                           /* this also lets the user set stdin and stdout */
  63 #endif
  64
  65   /* we cheat on the WAV header; we just bypass 44 bytes (simplest WAV
  66      header is 44 bytes) and assume that the data is 44.1khz, stereo, 16 bit
  67      little endian pcm samples. This is just an example, after all. */
  68
  69 #ifdef _WIN32 /* We need to set stdin/stdout to binary mode. Damn windows. */
  70   /* if we were reading/writing a file, it would also need to in
  71      binary mode, eg, fopen("file.wav","wb"); */
  72   /* Beware the evil ifdef. We avoid these where we can, but this one we
  73      cannot. Don't add any more, you'll probably go to hell if you do. */
  74   _setmode( _fileno( stdin ), _O_BINARY );
  75   _setmode( _fileno( stdout ), _O_BINARY );
  76 #endif
  77
  78
  79   /* we cheat on the WAV header; we just bypass the header and never
  80      verify that it matches 16bit/stereo/44.1kHz.  This is just an
  81      example, after all. */
  82
  83   readbuffer[0] = '\0';
  84   for (i=0, founddata=0; i<30 && ! feof(stdin) && ! ferror(stdin); i++)
  85   {
  86     fread(readbuffer,1,2,stdin);
  87
  88     if ( ! strncmp((char*)readbuffer, "da", 2) ){
  89       founddata = 1;
  90       fread(readbuffer,1,6,stdin);
  91       break;
  92     }
  93   }
  94
  95   /********** Encode setup ************/
  96
  97   vorbis_info_init(&vi);
  98
  99   /* choose an encoding mode.  A few possibilities commented out, one
 100      actually used: */
 101
 102   /*********************************************************************
 103    Encoding using a VBR quality mode.  The usable range is -.1
 104    (lowest quality, smallest file) to 1. (highest quality, largest file).
 105    Example quality mode .4: 44kHz stereo coupled, roughly 128kbps VBR
 106
 107    ret = vorbis_encode_init_vbr(&vi,2,44100,.4);
 108
 109    ---------------------------------------------------------------------
 110
 111    Encoding using an average bitrate mode (ABR).
 112    example: 44kHz stereo coupled, average 128kbps VBR
 113
 114    ret = vorbis_encode_init(&vi,2,44100,-1,128000,-1);
 115
 116    ---------------------------------------------------------------------
 117
 118    Encode using a quality mode, but select that quality mode by asking for
 119    an approximate bitrate.  This is not ABR, it is true VBR, but selected
 120    using the bitrate interface, and then turning bitrate management off:
 121
 122    ret = ( vorbis_encode_setup_managed(&vi,2,44100,-1,128000,-1) ||
 123            vorbis_encode_ctl(&vi,OV_ECTL_RATEMANAGE2_SET,NULL) ||
 124            vorbis_encode_setup_init(&vi));
 125
 126    *********************************************************************/
 127
 128   ret=vorbis_encode_init_vbr(&vi,2,44100,0.1);
 129
 130   /* do not continue if setup failed; this can happen if we ask for a
 131      mode that libVorbis does not support (eg, too low a bitrate, etc,
 132      will return 'OV_EIMPL') */
 133
 134   if(ret)exit(1);
 135
 136   /* add a comment */
 137   vorbis_comment_init(&vc);
 138   vorbis_comment_add_tag(&vc,"ENCODER","encoder_example.c");
 139
 140   /* set up the analysis state and auxiliary encoding storage */
 141   vorbis_analysis_init(&vd,&vi);
 142   vorbis_block_init(&vd,&vb);
 143
 144   /* set up our packet->stream encoder */
 145   /* pick a random serial number; that way we can more likely build
 146      chained streams just by concatenation */
 147   srand(time(NULL));
 148   ogg_stream_init(&os,rand());
 149
 150   /* Vorbis streams begin with three headers; the initial header (with
 151      most of the codec setup parameters) which is mandated by the Ogg
 152      bitstream spec.  The second header holds any comment fields.  The
 153      third header holds the bitstream codebook.  We merely need to
 154      make the headers, then pass them to libvorbis one at a time;
 155      libvorbis handles the additional Ogg bitstream constraints */
 156
 157   {
 158     ogg_packet header;
 159     ogg_packet header_comm;
 160     ogg_packet header_code;
 161
 162     vorbis_analysis_headerout(&vd,&vc,&header,&header_comm,&header_code);
 163     ogg_stream_packetin(&os,&header); /* automatically placed in its own
 164                                          page */
 165     ogg_stream_packetin(&os,&header_comm);
 166     ogg_stream_packetin(&os,&header_code);
 167
 168     /* This ensures the actual
 169      * audio data will start on a new page, as per spec
 170      */
 171     while(!eos){
 172       int result=ogg_stream_flush(&os,&og);
 173       if(result==0)break;
 174       fwrite(og.header,1,og.header_len,stdout);
 175       fwrite(og.body,1,og.body_len,stdout);
 176     }
 177
 178   }
 179
 180   while(!eos){
 181     long i;
 182     long bytes=fread(readbuffer,1,READ*4,stdin); /* stereo hardwired here */
 183
 184     if(bytes==0){
 185       /* end of file.  this can be done implicitly in the mainline,
 186          but it's easier to see here in non-clever fashion.
 187          Tell the library we're at end of stream so that it can handle
 188          the last frame and mark end of stream in the output properly */
 189       vorbis_analysis_wrote(&vd,0);
 190
 191     }else{
 192       /* data to encode */
 193
 194       /* expose the buffer to submit data */
 195       float **buffer=vorbis_analysis_buffer(&vd,READ);
 196
 197       /* uninterleave samples */
 198       for(i=0;i<bytes/4;i++){
 199         buffer[0][i]=((readbuffer[i*4+1]<<8)|
 200                       (0x00ff&(int)readbuffer[i*4]))/32768.f;
 201         buffer[1][i]=((readbuffer[i*4+3]<<8)|
 202                       (0x00ff&(int)readbuffer[i*4+2]))/32768.f;
 203       }
 204
 205       /* tell the library how much we actually submitted */
 206       vorbis_analysis_wrote(&vd,i);
 207     }
 208
 209     /* vorbis does some data preanalysis, then divvies up blocks for
 210        more involved (potentially parallel) processing.  Get a single
 211        block for encoding now */
 212     while(vorbis_analysis_blockout(&vd,&vb)==1){
 213
 214       /* analysis, assume we want to use bitrate management */
 215       vorbis_analysis(&vb,NULL);
 216       vorbis_bitrate_addblock(&vb);
 217
 218       while(vorbis_bitrate_flushpacket(&vd,&op)){
 219
 220         /* weld the packet into the bitstream */
 221         ogg_stream_packetin(&os,&op);
 222
 223         /* write out pages (if any) */
 224         while(!eos){
 225           int result=ogg_stream_pageout(&os,&og);
 226           if(result==0)break;
 227           fwrite(og.header,1,og.header_len,stdout);
 228           fwrite(og.body,1,og.body_len,stdout);
 229
 230           /* this could be set above, but for illustrative purposes, I do
 231              it here (to show that vorbis does know where the stream ends) */
 232
 233           if(ogg_page_eos(&og))eos=1;
 234         }
 235       }
 236     }
 237   }
 238
 239   /* clean up and exit.  vorbis_info_clear() must be called last */
 240
 241   ogg_stream_clear(&os);
 242   vorbis_block_clear(&vb);
 243   vorbis_dsp_clear(&vd);
 244   vorbis_comment_clear(&vc);
 245   vorbis_info_clear(&vi);
 246
 247   /* ogg_page and ogg_packet structs always point to storage in
 248      libvorbis.  They're never freed or manipulated directly */
 249
 250   fprintf(stderr,"Done.\n");
 251   return(0);
 252 }