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13<h1>SND_CalcDecibel <IMG src="../image/NTR.gif" width="24" height="12" border="0" align=middle><IMG src="../image/TWL.gif" width="24" height="12" border="0" align=middle></h1>
14<h2>Syntax</h2>
15<dl>
16<dd><pre class="funcsynopsisinfo"><code>#include &lt;nitro/snd.h&gt;</code></pre></dd>
17<dd><pre class="funcprototype"><code class="funcprototype">s16 SND_CalcDecibel( int <var>scale</var> );</code><br></pre></dd>
18</dl>
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20      <h2>Arguments</h2>
21
22      <div class="variablelist">
23<table border="0">
24<col align="left" valign="top">
25<tbody>
26<tr>
27<td><em><strong><code>scale</code></strong></em></td>
28<td>The scale value. Takes a value between 0 and 127.</td>
29</tr>
30</tbody>
31</table>
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33
34    </div>
35<div class="refsection" lang="ja"><a name="IDAOMYT"></a>
36      <h2>Return Values</h2>
37
38      <p>Returns the decibel value that corresponds to the scale value. Value is in units of 0.1dB</p>
39    </div>
40<div class="refsection" lang="ja"><a name="IDAVMYT"></a>
41      <h2>Description</h2>
42      <p>
43Calculates the decibel value.
44</p>
45      <p>
46The calculation is performed using the following equation:
47</p>
48      <pre class="programlisting">20 x log10( <em><strong><code>scale</code></strong></em> / 127 ) x 10</pre>
49
50      <p>
51Because the unit is 0.1dB, the number is multiplied by 10 as the final step.
52</p>
53      <p>
54When <em><strong><code>scale</code></strong></em> is 0, it returns -32768.
55</p>
56    </div>
57<h2>See Also</h2>
58<p>None.</p>
59<h2>Revision History</h2>
60<p>2005/09/22 Added explanation of when the scale value is 0.<br>2004/07/20 Initial version.</p>
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