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Bring in flac, ogg, vorbis
author Chris Cannam
date Tue, 19 Mar 2013 17:37:49 +0000
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+<html>
+
+<head>
+<title>vorbisfile - Example Code</title>
+<link rel=stylesheet href="style.css" type="text/css">
+</head>
+
+<body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff">
+<table border=0 width=100%>
+<tr>
+<td><p class=tiny>Vorbisfile documentation</p></td>
+<td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td>
+</tr>
+</table>
+
+<h1>Example Code: seeking</h1>
+
+<p>
+The following is a run-through of the seeking example program supplied
+with vorbisfile - <a href="seeking_test_c.html">seeking_test.c</a>.  
+This program tests the vorbisfile <a href="ov_time_seek.html">ov_time_seek</a> function by seeking to random points within the file.
+
+<p>
+First, relevant headers, including vorbis-specific "codec.h" and "vorbisfile.h" have to be included.
+
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+	<td>
+<pre><b>
+#include &lt;stdlib.h>
+#include &lt;stdio.h>
+#include "vorbis/codec.h"
+#include "vorbis/vorbisfile.h"
+</b></pre>
+	</td>
+</tr>
+</table>
+
+<p>Inside main(), we declare our primary OggVorbis_File structure.  We also declare other helpful variables to track our progress within the file.
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+        <td>
+<pre><b>
+int main(){
+  OggVorbis_File ov;
+  int i;
+</b></pre>
+        </td>
+</tr>
+</table>
+
+<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.
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+        <td>
+<pre><b>
+#ifdef _WIN32 /* We need to set stdin to binary mode under Windows */
+  _setmode( _fileno( stdin ), _O_BINARY );
+#endif
+</b></pre>
+        </td>
+</tr>
+</table>
+
+<p><a href="ov_open_callbacks.html">ov_open()</a> must be
+called to initialize the <a href="OggVorbis_File.html">OggVorbis_File</a> structure with default values.  
+<a href="ov_open_callbacks.html">ov_open_callbacks()</a> also checks to ensure that we're reading Vorbis format and not something else.
+
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+        <td>
+<pre><b>
+  if(ov_open_callbacks(stdin,&ov,NULL,-1, OV_CALLBACKS_NOCLOSE)<0){
+    printf("Could not open input as an OggVorbis file.\n\n");
+    exit(1);
+  }
+
+</b></pre>
+        </td>
+</tr>
+</table>
+
+<p>
+First we check to make sure the stream is seekable using <a href="ov_seekable.html">ov_seekable</a>.
+
+<p>Then we seek to 100 random spots in the bitstream using <a href="ov_time_seek.html">ov_time_seek</a> with randomly generated values.
+
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+        <td>
+<pre><b>
+  
+  /* print details about each logical bitstream in the input */
+  if(ov_seekable(&ov)){
+    double length=ov_time_total(&ov,-1);
+    printf("testing seeking to random places in %g seconds....\n",length);
+    for(i=0;i<100;i++){
+      double val=(double)rand()/RAND_MAX*length;
+      ov_time_seek(&ov,val);
+      printf("\r\t%d [%gs]...     ",i,val);
+      fflush(stdout);
+    }
+    
+    printf("\r                                   \nOK.\n\n");
+  }else{
+    printf("Standard input was not seekable.\n");
+  }
+  
+</b></pre>
+        </td>
+</tr>
+</table>
+<p>
+When we're done seeking, we need to call <a href="ov_clear.html">ov_clear()</a> to release the bitstream.
+
+<br><br>
+<table border=0 width=100% color=black cellspacing=0 cellpadding=7>
+<tr bgcolor=#cccccc>
+        <td>
+<pre><b>
+  ov_clear(&ov);
+  return 0;
+}
+</b></pre>
+        </td>
+</tr>
+</table>
+
+<p>
+The full source for seeking_test.c can be found with the vorbis
+distribution in <a href="seeking_test_c.html">seeking_test.c</a>.
+
+<br><br>
+<hr noshade>
+<table border=0 width=100%>
+<tr valign=top>
+<td><p class=tiny>copyright &copy; 2000-2010 Xiph.Org</p></td>
+<td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/">Ogg Vorbis</a></p></td>
+</tr><tr>
+<td><p class=tiny>Vorbisfile documentation</p></td>
+<td align=right><p class=tiny>vorbisfile version 1.3.2 - 20101101</p></td>
+</tr>
+</table>
+
+</body>
+
+</html>