opcodes/specdiff.xml


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65

<refentry id="specdiff">
<indexterm id="IndexSpecdiff"><primary>specdiff</primary></indexterm>
  <refentryinfo><title>Spectral Processing:Non-Standard</title></refentryinfo>
  <refmeta>
    <refentrytitle>specdiff</refentrytitle>
  </refmeta>

  <refnamediv>
    <refname>specdiff</refname>
    <refpurpose>
      Finds the positive difference values between consecutive spectral frames.
    </refpurpose>
  </refnamediv>
 
  <refsect1>
    <title>Description</title>
    <para>
      Finds the positive difference values between consecutive spectral frames.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Syntax</title>
    <synopsis>wsig <command>specdiff</command> wsigin</synopsis>
  </refsect1>
 
  <refsect1>
    <title>Performance</title>
    <para>
      <emphasis>wsig</emphasis> -- the output spectrum.
    </para>

    <para>
      <emphasis>wsigin</emphasis> -- the input spectra.
    </para>

    <para>
      Finds the positive difference values between consecutive spectral frames. At each new frame of <emphasis>wsigin</emphasis>, each magnitude value is compared with its predecessor, and the positive changes written to the output spectrum. This unit is useful as an energy onset detector.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Examples</title>
    <para>
      <informalexample>
        <programlisting>
  wsig2    <emphasis role="opc">specdiff</emphasis>    wsig1         <emphasis role="comment">; sense onsets</emphasis> 
  wsig3    <emphasis role="opc">specfilt</emphasis>    wsig2, 2      <emphasis role="comment">; absorb slowly</emphasis>
           <emphasis role="opc">specdisp</emphasis>    wsig2, 0.1    <emphasis role="comment">; &amp; display both spectra</emphasis>
           <emphasis role="opc">specdisp</emphasis>    wsig3, 0.1</programlisting>
      </informalexample>
    </para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <link linkend="specaddm"><citetitle>specaddm</citetitle></link>,
      <link linkend="specfilt"><citetitle>specfilt</citetitle></link>,
      <link linkend="spechist"><citetitle>spechist</citetitle></link>,
      <link linkend="specscal"><citetitle>specscal</citetitle></link>
    </para>
  </refsect1>
</refentry>