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<div id="projectname">libkate<span id="projectnumber"> 0.4.3</span>
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<div class="headertitle"><div class="title">Granule encoding </div></div>
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<div class="textblock"><p >Ogg leaves the encoding of granules up to a particular codec, only mandating that granules be non decreasing with time.</p>
<p >The Kate bitstream format uses a linear mapping between time and granule, described here.</p>
<p >A Kate granule position is composed of two different parts:</p><ul>
<li>a base granule, in the high bits</li>
<li>a granule offset, in the low bits</li>
</ul>
<pre class="fragment">+----------------+----------------+
| base | offset |
+----------------+----------------+
</pre><p >The number of bits these parts occupy is variable, and each stream may choose how many bits to dedicate to each. The <a class="el" href="structkate__info.html">kate_info</a> structure for a stream holds that information in the granule_shift field, so each part may be reconstructed from a granulepos.</p>
<p >The <a class="el" href="structkate__info.html">kate_info</a> structure for a stream also holds a rational fraction representing the time span of granule units.</p>
<p >The granule rate is defined by the two fields: </p><div class="fragment"><div class="line"><a class="code hl_variable" href="structkate__info.html#a7eb196702d96e5676b27838cadfd6acf">kate_info::gps_numerator</a></div>
<div class="line"><a class="code hl_variable" href="structkate__info.html#a00c2253966d5a22cc3e56f4f98dd4995">kate_info::gps_denominator</a></div>
<div class="ttc" id="astructkate__info_html_a00c2253966d5a22cc3e56f4f98dd4995"><div class="ttname"><a href="structkate__info.html#a00c2253966d5a22cc3e56f4f98dd4995">kate_info::gps_denominator</a></div><div class="ttdeci">kate_uint32_t gps_denominator</div><div class="ttdef"><b>Definition:</b> kate.h:287</div></div>
<div class="ttc" id="astructkate__info_html_a7eb196702d96e5676b27838cadfd6acf"><div class="ttname"><a href="structkate__info.html#a7eb196702d96e5676b27838cadfd6acf">kate_info::gps_numerator</a></div><div class="ttdeci">kate_uint32_t gps_numerator</div><div class="ttdef"><b>Definition:</b> kate.h:286</div></div>
</div><!-- fragment --><p >The number of bits reserved for the offset is defined by the field: </p><div class="fragment"><div class="line"><a class="code hl_variable" href="structkate__info.html#a1bf457732577344fa6d0f035d30d1e13">kate_info::granule_shift</a></div>
<div class="ttc" id="astructkate__info_html_a1bf457732577344fa6d0f035d30d1e13"><div class="ttname"><a href="structkate__info.html#a1bf457732577344fa6d0f035d30d1e13">kate_info::granule_shift</a></div><div class="ttdeci">unsigned char granule_shift</div><div class="ttdef"><b>Definition:</b> kate.h:283</div></div>
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