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
40signed char readbuffer[READ*4+44]; /* out of the data segment, not the stack */
41
42int 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}
253