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 21 encoder settings similar to the clasasic UNIX 'ioctl()' system call. 22 Applications may use vorbis_encode_ctl() to query or set bitrate 23 management or quality mode details by using one of several 24 <i>request</i> arguments detailed below. Vorbis_encode_ctl() must be 25 called after one of <a 26 href="vorbis_encode_setup_managed.html">vorbis_encode_setup_managed()</a> 27 or <a 28 href="vorbis_encode_setup_vbr.html">vorbis_encode_setup_vbr()</a>. 29 When used to modify settings, vorbis_encode_ctl() must be called 30 before <a 31 href="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> 39 extern 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 62 ovectl_ratemanage2_arg *</a></b><br> Used to query the current 63 encoder bitrate management setting. Also used to initialize fields of 64 an ovectl_ratemanage2_arg structure for use with 65 OV_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 69 ovectl_ratemanage2_arg *</a></b><br> Used to set the current 70 encoder bitrate management settings to the values listed in the 71 ovectl_ratemanage2_arg. Passing a NULL pointer will disable bitrate 72 management. 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 77 setting (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 87 block 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 90 the impulse block bias to the the value pointed to by arg; valid range 91 is -15.0 to 0.0 [default]. A negative impulse block bias will direct 92 to encoder to use more bits when incoding short blocks that contain 93 strong 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> 97 Returns the current encoder coupling enabled/disabled 98 setting 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> 103 Enables/disables channel coupling in multichannel encoding according to arg. 104 *arg of zero disables all channel coupling, nonzero allows the encoder to use 105 coupling if a coupled mode is available for the input. At present, coupling 106 is 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 113 ovectl_ratemanage_arg *</a></b><br> Old interface to querying bitrate 114 management settings; deprecated after move to bit-reservoir style 115 management in 1.1 rendered this interface partially obsolete. Please 116 use 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 123 ovectl_ratemanage_arg *</a></b><br> Old interface to modifying bitrate 124 management settings; deprecated after move to bit-reservoir style 125 management in 1.1 rendered this interface partially obsolete. Please 126 use 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 132 ovectl_ratemanage_arg *</a></b><br> Old interface to setting 133 average-bitrate encoding mode; deprecated after move to bit-reservoir 134 style management in 1.1 rendered this interface partially obsolete. 135 Please 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 141 ovectl_ratemanage_arg *</a></b><br> Old interface to setting 142 bounded-bitrate encoding modes; deprecated after move to bit-reservoir 143 style management in 1.1 rendered this interface partially obsolete. 144 Please 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, 152 placing any further return information (such as the result of a query) 153 into the storage pointed to by <i>*arg</i>. On error, 154 vorbis_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 159 setting after calling <a 160 href="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 (a] vorbis.org">team (a] 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
