1<html> 2 3<head> 4<title>libvorbisenc - function - vorbis_encode_ctl</title> 5<link rel=stylesheet href="style.css" type="text/css"> 6</head> 7 8<body bgcolor=white text=black link="#5555ff" alink="#5555ff" vlink="#5555ff"> 9<table border=0 width=100%> 10<tr> 11<td><p class=tiny>libvorbisenc documentation</p></td> 12<td align=right><p class=tiny>libvorbisenc release 1.1 - 20040709</p></td> 13</tr> 14</table> 15 16<h1>vorbis_encode_ctl</h1> 17 18<p><i>declared in "vorbis/vorbisenc.h";</i></p> 19 20<p>This function implements a generic interface to miscellaneous 21encoder settings similar to the clasasic UNIX 'ioctl()' system call. 22Applications may use vorbis_encode_ctl() to query or set bitrate 23management or quality mode details by using one of several 24<i>request</i> arguments detailed below. Vorbis_encode_ctl() must be 25called after one of <a 26href="vorbis_encode_setup_managed.html">vorbis_encode_setup_managed()</a> 27or <a 28href="vorbis_encode_setup_vbr.html">vorbis_encode_setup_vbr()</a>. 29When used to modify settings, vorbis_encode_ctl() must be called 30before <a 31href="vorbis_encode_setup_init.html">vorbis_encode_setup_init()</a>. 32 33<p> 34<br><br> 35<table border=0 color=black cellspacing=0 cellpadding=7> 36<tr bgcolor=#cccccc> 37 <td> 38<pre><b> 39extern int vorbis_encode_ctl(vorbis_info *vi,int request,void *arg); 40 41</b></pre> 42 </td> 43</tr> 44</table> 45 46<h3>Parameters</h3> 47<dl> 48<dt><i>vi</i></dt> 49<dd>Pointer to an initialized <a href="vorbis_info.html">vorbis_info</a> struct.</dd><p> 50<dt><i>request</i></dt> 51<dd>Specifies the desired action; possible request fields are detailed below.</dd><p> 52<dt><i>arg</i></dt> 53<dd>void * pointing to a data structure matching the request argument.</dd><p> 54</dl><p> 55 56<h3>Requests</h3> 57<dl> 58 59<dt><i>OV_ECTL_RATEMANAGE2_GET</i></dt> 60 61<dd><b>Argument: <a href="ovectl_ratemanage2_arg.html">struct 62ovectl_ratemanage2_arg *</a></b><br> Used to query the current 63encoder bitrate management setting. Also used to initialize fields of 64an ovectl_ratemanage2_arg structure for use with 65OV_ECTL_RATEMANAGE2_SET.</dd><p> 66 67<dt><i>OV_ECTL_RATEMANAGE2_SET</i></dt> 68<dd><b>Argument: <a href="ovectl_ratemanage2_arg.html">struct 69ovectl_ratemanage2_arg *</a></b><br> Used to set the current 70encoder bitrate management settings to the values listed in the 71ovectl_ratemanage2_arg. Passing a NULL pointer will disable bitrate 72management. 73</dd><p> 74 75<dt><i>OV_ECTL_LOWPASS_GET</i></dt> 76<dd><b>Argument: double *</b><br> Returns the current encoder hard-lowpass 77setting (kHz) in the double pointed to by arg. 78</dd><p> 79 80<dt><i>OV_ECTL_LOWPASS_SET</i></dt> 81<dd><b>Argument: double *</b><br> Sets the encoder hard-lowpass to the value 82(kHz) pointed to by arg. Valid lowpass settings range from 2 to 99. 83</dd><p> 84 85<dt><i>OV_ECTL_IBLOCK_GET</i></dt> 86<dd><b>Argument: double *</b><br> Returns the current encoder impulse 87block setting in the double pointed to by arg.</dd><p> 88 89<dt><i>OV_ECTL_IBLOCK_SET</i></dt> <dd><b>Argument: double *</b><br> Sets 90the impulse block bias to the the value pointed to by arg; valid range 91is -15.0 to 0.0 [default]. A negative impulse block bias will direct 92to encoder to use more bits when incoding short blocks that contain 93strong impulses, thus improving the accuracy of impulse encoding.</dd><p> 94 95<dt><i>OV_ECTL_COUPLING_GET</i></dt> 96<dd><b>Argument: int *</b><br> 97Returns the current encoder coupling enabled/disabled 98setting in the int pointed to by arg. 99</dd><p> 100 101<dt><i>OV_ECTL_COUPLING_SET</i></dt> 102<dd><b>Argument: int *</b><br> 103Enables/disables channel coupling in multichannel encoding according to arg. 104*arg of zero disables all channel coupling, nonzero allows the encoder to use 105coupling if a coupled mode is available for the input. At present, coupling 106is available for stereo and 5.1 input modes. 107</dd><p> 108 109<dt><i>OV_ECTL_RATEMANAGE_GET [deprecated]</i></dt> 110<dd> 111 112<b>Argument: <a href="ovectl_ratemanage_arg.html">struct 113ovectl_ratemanage_arg *</a></b><br> Old interface to querying bitrate 114management settings; deprecated after move to bit-reservoir style 115management in 1.1 rendered this interface partially obsolete. Please 116use OV_ECTL_RATEMANGE2_GET instead. 117 118</dd><p> 119 120<dt><i>OV_ECTL_RATEMANAGE_SET [deprecated]</i></dt> 121<dd> 122<b>Argument: <a href="ovectl_ratemanage_arg.html">struct 123ovectl_ratemanage_arg *</a></b><br> Old interface to modifying bitrate 124management settings; deprecated after move to bit-reservoir style 125management in 1.1 rendered this interface partially obsolete. Please 126use OV_ECTL_RATEMANGE2_SET instead. 127</dd><p> 128 129<dt><i>OV_ECTL_RATEMANAGE_AVG [deprecated]</i></dt> 130<dd> 131<b>Argument: <a href="ovectl_ratemanage_arg.html">struct 132ovectl_ratemanage_arg *</a></b><br> Old interface to setting 133average-bitrate encoding mode; deprecated after move to bit-reservoir 134style management in 1.1 rendered this interface partially obsolete. 135Please use OV_ECTL_RATEMANGE2_SET instead. 136</dd><p> 137 138<dt><i>OV_ECTL_RATEMANAGE_HARD [deprecated]</i></dt> 139<dd> 140<b>Argument: <a href="ovectl_ratemanage_arg.html">struct 141ovectl_ratemanage_arg *</a></b><br> Old interface to setting 142bounded-bitrate encoding modes; deprecated after move to bit-reservoir 143style management in 1.1 rendered this interface partially obsolete. 144Please use OV_ECTL_RATEMANGE2_SET instead. 145</dd><p> 146 147 148</dl> 149 150 151<h3>Return Values</h3> vorbis_encode_ctl() returns zero on success, 152placing any further return information (such as the result of a query) 153into the storage pointed to by <i>*arg</i>. On error, 154vorbis_encode_ctl() may return one of the following error codes: 155 156<dl> 157 158<dt>OV_EINVAL</dt><dd>Invalid argument, or an attempt to modify a 159setting after calling <a 160href="vorbis_encode_setup_init.html">vorbis_encode_setup_init()</a>.</dd><p> 161 162<dt>OV_EIMPL</dt><dd>Unimplemented or unknown request</dd><p> 163 164</dl> 165 166<p> 167 168<br><br> 169<hr noshade> 170<table border=0 width=100%> 171<tr valign=top> 172<td><p class=tiny>copyright © 2004 xiph.org</p></td> 173<td align=right><p class=tiny><a href="http://www.xiph.org/ogg/vorbis/index.html">Ogg Vorbis</a><br><a href="mailto:team@vorbis.org">team@vorbis.org</a></p></td> 174</tr><tr> 175<td><p class=tiny>libvorbisenc documentation</p></td> 176<td align=right><p class=tiny>libvorbisenc release 1.1 - 20040709</p></td> 177</tr> 178</table> 179 180 181</body> 182 183</html> 184