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Replace these with versions built using an older toolset (so as to avoid ABI compatibilities when linking on Ubuntu 14.04 for packaging purposes)
author Chris Cannam
date Fri, 07 Feb 2020 11:51:13 +0000
parents 05aa0afa9217
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Chris@1 1 <html>
Chris@1 2
Chris@1 3 <head>
Chris@1 4 <title>vorbisfile - Example Code</title>
Chris@1 5 <link rel=stylesheet href="style.css" type="text/css">
Chris@1 6 </head>
Chris@1 7
Chris@1 8 <body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff">
Chris@1 9 <table border=0 width=100%>
Chris@1 10 <tr>
Chris@1 11 <td><p class=tiny>Vorbisfile documentation</p></td>
Chris@1 12 <td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td>
Chris@1 13 </tr>
Chris@1 14 </table>
Chris@1 15
Chris@1 16 <h1>Chaining Example Code</h1>
Chris@1 17
Chris@1 18 <p>
Chris@1 19 The following is a run-through of the chaining example program supplied
Chris@1 20 with vorbisfile - <a href="chaining_example_c.html">chaining_example.c</a>.
Chris@1 21 This program demonstrates how to work with a chained bitstream.
Chris@1 22
Chris@1 23 <p>
Chris@1 24 First, relevant headers, including vorbis-specific "codec.h" and "vorbisfile.h" have to be included.
Chris@1 25
Chris@1 26 <br><br>
Chris@1 27 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 28 <tr bgcolor=#cccccc>
Chris@1 29 <td>
Chris@1 30 <pre><b>
Chris@1 31 #include "vorbis/codec.h"
Chris@1 32 #include "vorbis/vorbisfile.h"
Chris@1 33 #include "../lib/misc.h"
Chris@1 34 </b></pre>
Chris@1 35 </td>
Chris@1 36 </tr>
Chris@1 37 </table>
Chris@1 38
Chris@1 39 <p>Inside main(), we declare our primary OggVorbis_File structure. We also declare a other helpful variables to track our progress within the file.
Chris@1 40 <br><br>
Chris@1 41 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 42 <tr bgcolor=#cccccc>
Chris@1 43 <td>
Chris@1 44 <pre><b>
Chris@1 45 int main(){
Chris@1 46 OggVorbis_File ov;
Chris@1 47 int i;
Chris@1 48 </b></pre>
Chris@1 49 </td>
Chris@1 50 </tr>
Chris@1 51 </table>
Chris@1 52
Chris@1 53 <p>This example takes its input on stdin which is in 'text' mode by default under Windows; this will corrupt the input data unless set to binary mode. This applies only to Windows.
Chris@1 54 <br><br>
Chris@1 55 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 56 <tr bgcolor=#cccccc>
Chris@1 57 <td>
Chris@1 58 <pre><b>
Chris@1 59 #ifdef _WIN32 /* We need to set stdin to binary mode under Windows */
Chris@1 60 _setmode( _fileno( stdin ), _O_BINARY );
Chris@1 61 #endif
Chris@1 62 </b></pre>
Chris@1 63 </td>
Chris@1 64 </tr>
Chris@1 65 </table>
Chris@1 66
Chris@1 67 <p>We call <a href="ov_open_callbacks.html">ov_open_callbacks()</a> to
Chris@1 68 initialize the <a href="OggVorbis_File.html">OggVorbis_File</a>
Chris@1 69 structure. <a href="ov_open_callbacks.html">ov_open_callbacks()</a>
Chris@1 70 also checks to ensure that we're reading Vorbis format and not
Chris@1 71 something else. The OV_CALLBACKS_NOCLOSE callbacks instruct
Chris@1 72 libvorbisfile not to close stdin later during cleanup.<p>
Chris@1 73
Chris@1 74 <br><br>
Chris@1 75 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 76 <tr bgcolor=#cccccc>
Chris@1 77 <td>
Chris@1 78 <pre><b>
Chris@1 79 if(ov_open_callbacks(stdin,&ov,NULL,-1,OV_CALLBACKS_NOCLOSE)<0){
Chris@1 80 printf("Could not open input as an OggVorbis file.\n\n");
Chris@1 81 exit(1);
Chris@1 82 }
Chris@1 83
Chris@1 84 </b></pre>
Chris@1 85 </td>
Chris@1 86 </tr>
Chris@1 87 </table>
Chris@1 88
Chris@1 89 <p>
Chris@1 90 First we check to make sure the stream is seekable using <a href="ov_seekable.html">ov_seekable</a>.
Chris@1 91
Chris@1 92 <p>Then we're going to find the number of logical bitstreams in the physical bitstream using <a href="ov_streams.html">ov_streams</a>.
Chris@1 93
Chris@1 94 <p>We use <a href="ov_time_total.html">ov_time_total</a> to determine the total length of the physical bitstream. We specify that we want the entire bitstream by using the argument <tt>-1</tt>.
Chris@1 95
Chris@1 96 <br><br>
Chris@1 97 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 98 <tr bgcolor=#cccccc>
Chris@1 99 <td>
Chris@1 100 <pre><b>
Chris@1 101 if(ov_seekable(&amp;ov)){
Chris@1 102 printf("Input bitstream contained %ld logical bitstream section(s).\n",
Chris@1 103 ov_streams(&amp;ov));
Chris@1 104 printf("Total bitstream playing time: %ld seconds\n\n",
Chris@1 105 (long)ov_time_total(&amp;ov,-1));
Chris@1 106
Chris@1 107 }else{
Chris@1 108 printf("Standard input was not seekable.\n"
Chris@1 109 "First logical bitstream information:\n\n");
Chris@1 110 }
Chris@1 111
Chris@1 112 </b></pre>
Chris@1 113 </td>
Chris@1 114 </tr>
Chris@1 115 </table>
Chris@1 116
Chris@1 117 <p>Now we're going to iterate through each logical bitstream and print information about that bitstream.
Chris@1 118
Chris@1 119 <p>We use <a href="ov_info.html">ov_info</a> to pull out the <a href="../libvorbis/vorbis_info.html">vorbis_info</a> struct for each logical bitstream. This struct contains bitstream-specific info.
Chris@1 120
Chris@1 121 <p><a href="ov_serialnumber.html">ov_serialnumber</a> retrieves the unique serial number for the logical bistream. <a href="ov_raw_total.html">ov_raw_total</a> gives the total compressed bytes for the logical bitstream, and <a href="ov_time_total.html">ov_time_total</a> gives the total time in the logical bitstream.
Chris@1 122
Chris@1 123 <br><br>
Chris@1 124 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 125 <tr bgcolor=#cccccc>
Chris@1 126 <td>
Chris@1 127 <pre><b>
Chris@1 128 for(i=0;i&lt;ov_streams(&amp;ov);i++){
Chris@1 129 vorbis_info *vi=ov_info(&amp;ov,i);
Chris@1 130 printf("\tlogical bitstream section %d information:\n",i+1);
Chris@1 131 printf("\t\t%ldHz %d channels bitrate %ldkbps serial number=%ld\n",
Chris@1 132 vi-&gt;rate,vi-&gt;channels,ov_bitrate(&amp;ov,i)/1000,
Chris@1 133 ov_serialnumber(&amp;ov,i));
Chris@1 134 printf("\t\tcompressed length: %ld bytes ",(long)(ov_raw_total(&amp;ov,i)));
Chris@1 135 printf(" play time: %lds\n",(long)ov_time_total(&amp;ov,i));
Chris@1 136 }
Chris@1 137 </b></pre>
Chris@1 138 </td>
Chris@1 139 </tr>
Chris@1 140 </table>
Chris@1 141 <p>
Chris@1 142 When we're done with the entire physical bitstream, we need to call <a href="ov_clear.html">ov_clear()</a> to release the bitstream.
Chris@1 143
Chris@1 144 <br><br>
Chris@1 145 <table border=0 width=100% color=black cellspacing=0 cellpadding=7>
Chris@1 146 <tr bgcolor=#cccccc>
Chris@1 147 <td>
Chris@1 148 <pre><b>
Chris@1 149 ov_clear(&amp;ov);
Chris@1 150 return 0;
Chris@1 151 }
Chris@1 152 </b></pre>
Chris@1 153 </td>
Chris@1 154 </tr>
Chris@1 155 </table>
Chris@1 156
Chris@1 157 <p>
Chris@1 158 The full source for chaining_example.c can be found with the vorbis
Chris@1 159 distribution in <a href="chaining_example_c.html">chaining_example.c</a>.
Chris@1 160
Chris@1 161 <br><br>
Chris@1 162 <hr noshade>
Chris@1 163 <table border=0 width=100%>
Chris@1 164 <tr valign=top>
Chris@1 165 <td><p class=tiny>copyright &copy; 2000-2010 Xiph.Org</p></td>
Chris@1 166 <td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td>
Chris@1 167 </tr><tr>
Chris@1 168 <td><p class=tiny>Vorbisfile documentation</p></td>
Chris@1 169 <td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td>
Chris@1 170 </tr>
Chris@1 171 </table>
Chris@1 172
Chris@1 173 </body>
Chris@1 174
Chris@1 175 </html>