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 16946 2010-03-03 16:12:40Z 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 } 253
