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1337 lines
38 KiB
1337 lines
38 KiB
<!-- <?xml version="1.0" ?>
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<!DOCTYPE chapter PUBLIC "-//KDE//DTD DocBook XML V4.2-Based Variant V1.1//EN" "dtd/kdex.dtd">
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To validate or process this file as a standalone document, uncomment
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this prolog. Be sure to comment it out again when you are done -->
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<chapter id="arts-modules">
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<title>&arts; modules</title>
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<sect1 id="modules-introduction">
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<title>Introduction</title>
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<para>
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This chapter describes all of the standard &arts; modules. One of the
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most powerful features of &arts;, modules can be connected together into
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structures to implement new functions such as effects and instruments.
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</para>
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<para>
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Modules are broken down into two categories. Synthesis modules are used
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for implementing the <quote>plumbing</quote> that manipulates multimedia
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data streams to implement new effects, instruments, mixers, and
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applications. Visual modules allow you to provide a graphical user
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interface to control the sound structures that are built up with the
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synthesis modules.
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</para>
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</sect1>
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<sect1 id="synth-modules-reference">
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<title>Synthesis Modules Reference</title>
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<para>
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</para>
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<sect2 id="mcat-synth-arithmetic-mixing">
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<title>Arithmetic + Mixing</title>
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<para>
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</para>
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<sect3 id="mref-synth-add-sect">
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<title>Synth_ADD</title>
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<anchor id="mref-synth-add" />
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/Synth_ADD.png" format="PNG"/></imageobject>
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<textobject><phrase>Synth_ADD</phrase></textobject>
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</mediaobject>
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<para>
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This adds two signals.
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</para>
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</sect3>
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<sect3 id="mref-synth-mul-sect">
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<title>Synth_MUL</title>
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<anchor id="mref-synth-mul"/>
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/Synth_MUL.png" format="PNG"/></imageobject>
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<textobject><phrase>Synth_MUL</phrase></textobject>
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</mediaobject>
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<para>
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This multiplies a signal by a factor. You can use this to scale signals
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down (0 < factor < 1) or up (factor > 1) or invert signals
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(factor < 0). Note that the factor may be a signal and don't has to
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be constant (⪚ envelope or real signal).
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</para>
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</sect3>
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<sect3 id="mref-synth-div-sect">
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<title>Synth_DIV</title>
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<anchor id="mref-synth-div"/>
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/Synth_DIV.png" format="PNG"/></imageobject>
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<textobject><phrase>Synth_DIV</phrase></textobject>
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</mediaobject>
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<para>
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This divides a signal by a factor. You can use this to do divide one signal
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by another one. Or set invalue1 to 1 and you will get the
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reciprocal of the invalue2 as outvalue. Take care that invalue2 never
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reaches 0 or you will get problems with divisions by zero.
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</para>
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</sect3>
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<sect3 id="mref-synth-multi-add-sect">
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<title>Synth_MULTI_ADD</title>
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<anchor id="mref-synth-multi-add" />
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/Synth_MULTI_ADD.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_MULTI_ADD</phrase></textobject>
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</mediaobject>
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<para>
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This adds an arbitrary number of signals. If you need to sum up the
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waveforms produces by four different oscillators, you for instance can
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connect all their outputs to one Synth_MULTI_ADD
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module. This is more efficient than using three Synth_ADD
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modules.
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</para>
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</sect3>
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<sect3 id="mref-synth-xfade-sect">
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<title>Synth_XFADE</title>
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<anchor id="mref-synth-xfade" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_XFADE.png" format="PNG"/>
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</imageobject>
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<textobject><phrase>Synth_XFADE</phrase></textobject>
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</mediaobject>
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<para>
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This crossfades two signals. If the percentage input is -1, only the
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left signal is heard, if it is 1, only the right signal is heard. When
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it is 0, both signals a heard with the same volume.
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</para>
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<para>
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This allows you to ensure that your signal stays in a well defined
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range. If you had two signals that were between -1 and 1 before
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crossfading, they will be in the same range after crossfading.
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</para>
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</sect3>
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<sect3 id="mref-synth-autopanner-sect">
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<title>Synth_AUTOPANNER</title>
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<anchor id="mref-synth-autopanner" />
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<para>
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The opposite of a crossfader. This takes a mono signal and splits it
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into a stereo signal: It is used to automatically pan the input signal
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between the left and the right output. This makes mixes more lively. A
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standard application would be a guitar or lead sound.
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</para>
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<para>
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Connect a <acronym>LFO</acronym>, a sine or saw wave for example to
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inlfo. and select a frequency between 0.1 and 5Hz for a traditional
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effect or even more for Special <acronym>FX</acronym>.
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</para>
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</sect3>
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</sect2>
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<sect2 id="mcat-synth-busses">
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<title>Busses</title>
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<sect3 id="mref-synth-bus-uplink-sect">
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<title>Synth_BUS_UPLINK</title>
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<anchor id="mref-synth-bus-uplink" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_BUS_UPLINK.png"
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format="PNG"/>
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</imageobject>
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<textobject><phrase>Synth_BUS_UPLINK</phrase></textobject>
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</mediaobject>
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<para>
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An uplink to a bus. Give signals to left and right, and the name of the
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bus where the data should go on the <quote>bus</quote> port. The
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combined signal from all uplinks with this name will appear on every
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downlink on that <quote>bus</quote>.
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</para>
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</sect3>
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<sect3 id="mref-synth-bus-downlink-sect">
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<title>Synth_BUS_DOWNLINK</title>
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<anchor id="mref-synth-bus-downlink" />
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<mediaobject>
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<imageobject>
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<imagedata fileref="images/Synth_BUS_DOWNLINK.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_BUS_DOWNLINK</phrase></textobject>
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</mediaobject>
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<para>
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Gets (the sum of) all data that is put to a certain bus (with the name
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you specify at the <quote>bus</quote> port).
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</para>
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</sect3>
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</sect2>
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<!-- TODO AFTER KDE2.1: move freeverb into delays, and rename category to
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Delays & reverbs -->
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<sect2 id="mcat-synth-delays">
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<title>Delays</title>
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<para>
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</para>
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<sect3 id="mref-synth-delay-sect">
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<title>Synth_DELAY</title>
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<anchor id="mref-synth-delay" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_DELAY.png"
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format="PNG"/></imageobject></mediaobject>
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<para>
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This delays the input signal for an amount of time. The time
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specification must be between 0 and maxdelay for a delay between 0 and
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maxdelay seconds.
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</para>
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<para>
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This kind of delay <emphasis>may not be used</emphasis> in feedback
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structures. This is because it's a variable delay. You can modify it's
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length while it is running, and even set it down to zero. But since in a
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feedback structure the own output is needed to calculate the next
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samples, a delay whose value could drop to zero during synthesis could
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lead to a stall situation.
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</para>
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<para>
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Use CDELAYs in that setup, perhaps combine a small constant delay (of
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0.001 seconds) with a flexible delay.
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</para>
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<para>
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You can also combine a CDELAY and a DELAY to achieve a variable length
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delay with a minimum value in a feedback loop. Just make sure that you
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have a CDELAY involved.
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</para>
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</sect3>
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<sect3 id="mref-synth-cdelay-sect">
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<title>Synth_CDELAY</title>
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<anchor id="mref-synth-cdelay" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_CDELAY.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_CDELAY</phrase></textobject>
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</mediaobject>
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<para>
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This delays the input signal for an amount of time. The time
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specification must be greater than 0 for a delay of 0 seconds or more.
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The delay is constant during the calculation, that means it
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can't be modified.
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</para>
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<para>
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This saves computing time as no interpolation is done, and is useful for
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recursive structures. See description above (Synth_DELAY).
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</para>
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</sect3>
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</sect2>
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<sect2 id="mcat-synth-envelopes">
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<title>Envelopes</title>
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<para>
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</para>
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<sect3 id="mref-synth-envelope-adsr-sect">
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<title>Synth_ENVELOPE_ADSR</title>
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<anchor id="mref-synth-envelope-adsr" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_ENVELOPE_ADSR.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_ENVELOPE_ADSR</phrase></textobject>
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</mediaobject>
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<para>
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This is a classic <acronym>ADSR</acronym> envelope which means you
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specify:
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</para>
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<variablelist>
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<varlistentry>
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<term>active</term>
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<listitem>
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<para>
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Whether the note is being pressed right now by the user.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>invalue</term>
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<listitem>
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<para>
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The input signal.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>attack</term>
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<listitem>
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<para>
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The time that should pass between the user presses the note and the signal
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reaching it's maximum amplitude (in seconds).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>decay</term>
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<listitem>
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<para>
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The time that should pass between the the signal reaching it's maximum
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amplitude and the signal going back to some constant level (in seconds).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>sustain</term>
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<listitem>
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<para>
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The constant level the signal is held at afterwards, until the user
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releases the note.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>release</term>
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<listitem>
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<para>
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The time that should pass after the user has released the note until the
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signal is scaled down to zero (in seconds).
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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<para>
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You'll get the scaled signal at outvalue. If the <acronym>ASDR</acronym>
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envelope is finished, it will set done to 1. You can use this to provide
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the <quote>done</quote> output of an instrument (which will make the
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instrument structure be deleted by the &MIDI; router object once the
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release phase is over).
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</para>
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</sect3>
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<sect3 id="mref-synth-pscale-sect">
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<title>Synth_PSCALE</title>
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<anchor id="mref-synth-pscale" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_PSCALE.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_PSCALE</phrase></textobject>
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</mediaobject>
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<para>
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The Synth_PSCALE module will scale the audio stream that is
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directed through it from a volume 0 (silent) to 1 (original loudness)
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back to 0 (silent). According to the position (get the position from
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Synth_SEQUENCE). The position where the peak should occur can be
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given as pos.
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</para>
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<para>
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Example: Setting top to 0.1 means that after 10% of the note has
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been played, the volume has reached its maximum, and starts decaying
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afterwards.
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</para>
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</sect3>
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</sect2>
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<sect2 id="mcat-synth-effects">
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<title>Effects</title>
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<sect3 id="mref-synth-freeverb-sect">
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<title>Synth_FREEVERB</title>
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<anchor id="mref-synth-freeverb" />
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<mediaobject>
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<imageobject><imagedata fileref="images/Synth_FREEVERB.png"
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format="PNG"/></imageobject>
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<textobject><phrase>Synth_FREEVERB</phrase></textobject>
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</mediaobject>
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<para>
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This is a reverb effect. In the current implementation, it is thought to
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pass a stereo signal through the reverb, and it will -add- it's reverb
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effect to the signal.
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</para>
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<note>
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<para>
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This means that it can be used inside an StereoEffectStack as well.
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</para>
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</note>
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<para>
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The input signal should be connected to (inleft, inright), the output
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signal will be (outleft, outright).
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</para>
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<para>
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The parameters which you can configure are:
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</para>
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<variablelist>
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<varlistentry>
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<term>roomsize</term>
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<listitem>
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<para>
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The size of the room which the reverb simulates (range: 0..1, where 1 is
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the largest possible room).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>damp</term>
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<listitem>
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<para>
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This specifies a filter which will make the simulated room absorb high
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frequencies (range 0..1, where 1 means absorb high frequencies quite
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aggressive).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term>wet</term>
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<listitem>
|
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<para>
|
|
The amount of reverb-signal (that is, the amount of the signal that
|
|
should be modified by the filters, resulting in a <quote>wet</quote>,
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that is <quote>reverb sound</quote>.
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|
</para>
|
|
</listitem>
|
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</varlistentry>
|
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<varlistentry>
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<term>dry</term>
|
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<listitem>
|
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<para>
|
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The amount of pure signal passed through, resulting in an echo (or
|
|
combined delay) rather than reverb effect (range: 0..1).
|
|
</para>
|
|
<!-- TODO: do some measurements to show that this documentation -is- correct,
|
|
I am not sure if it is echo, or really pure (non-delayed), or multiple delay
|
|
or whatever -->
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>width</term>
|
|
<listitem>
|
|
<para>
|
|
The amount of stereo-magic the reverb algorithm adds to the reverb
|
|
effect, making the reverb sound wider in the stereo panorama (range:
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|
0..1).
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|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
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<varlistentry>
|
|
<term>mode</term>
|
|
<listitem>
|
|
<para>
|
|
[ TODO: I think if mode is 1, the reverb holds the current image of the
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|
sound, whereas 0 is normal operation ]
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-tremolo-sect">
|
|
<title>Synth_TREMOLO</title>
|
|
<anchor id="mref-synth-tremolo" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_TREMOLO.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_TREMOLO</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
The tremolo module modulates the amplitude according to a
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|
<acronym>LFO</acronym>-Wave. Traditionally you would use a sine wave
|
|
but why limit yourself? What you get is a very intense effect that cuts
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|
through most arrangements because of its high dynamic range. The
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|
tremolo effect is still one of guitarists favorite effects although
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|
it's not as popular as in the 1960's.
|
|
</para>
|
|
|
|
<para>
|
|
[ TODO: currently this is implemented as invalue + abs(inlfo) - maybe it
|
|
would make more sense to implement it as invalue * (1+inlfo*depth),
|
|
where depth would be a parameter between 0..1 - decide this after &kde;2.1
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|
; if you have a comment, send a mail to the &arts; list ;). ]
|
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</para>
|
|
|
|
</sect3>
|
|
<sect3 id="mref-synth-fx-cflanger-sect">
|
|
<title>Synth_FX_CFLANGER</title>
|
|
<anchor id="mref-synth-fx-cflanger" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_FX_CFLANGER.png" format="PNG" /></imageobject>
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|
<textobject><phrase>Synth_FX_CFLANGER</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
A flanger is a time-varying delay effect. To make development of complex
|
|
flanger effects simpler, this module is provided, which contains the
|
|
core of a one-channel flanger.
|
|
</para>
|
|
|
|
<para>It has the following ports:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>invalue</term>
|
|
<listitem>
|
|
<para>
|
|
The signal which you want to process.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>lfo</term>
|
|
<listitem>
|
|
<para>
|
|
Preferably a sine wave which modulates the delay time inside the
|
|
flanger (-1 .. 1).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>mintime</term>
|
|
<listitem>
|
|
<para>
|
|
The minimum value for the delay inside the flanger in milliseconds.
|
|
Suggested values: try something like 1 ms. Please use values < 1000
|
|
ms.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>maxtime</term>
|
|
<listitem>
|
|
<para>
|
|
The minimum value for the delay inside the flanger in milliseconds.
|
|
Suggested values: try something like 5 ms. Please use values < 1000
|
|
ms.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>outvalue</term>
|
|
<listitem>
|
|
<para>
|
|
The output signal. It is important that you mix that with the
|
|
original (unflanged) signal to get the desired effect.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<tip>
|
|
<para>
|
|
You can use this as a basis for a chorus effect.
|
|
</para>
|
|
</tip>
|
|
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-filters">
|
|
<title>Filters</title>
|
|
|
|
<sect3 id="mref-synth-pitch-shift-sect">
|
|
<title>Synth_PITCH_SHIFT</title>
|
|
<anchor id="mref-synth-pitch-shift" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_PITCH_SHIFT.png" format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_PITCH_SHIFT</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This pitch shifting effect changes the frequency of the input signal
|
|
without affecting the speed. An application for this is for instance
|
|
changing the pitch of your voice while you record (and replay) it in
|
|
realtime.
|
|
</para>
|
|
|
|
<para>
|
|
The <emphasis>speed</emphasis> parameter is the relative speed with
|
|
which the signal will be replayed. So a speed of two would make it sound
|
|
twice as high (&ie; an input frequency of 440 Hz would result in an
|
|
output frequency of 880 Hz).
|
|
</para>
|
|
|
|
<para>
|
|
The <emphasis>frequency</emphasis> parameter is used internally to
|
|
switch between different grains of the signal. It is tunable, and
|
|
depending on your choice, the pitch shifting will sound more or less
|
|
realistic for your use case. A good value to start with is something
|
|
like 5 or 10.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-shelve-cutoff-sect">
|
|
<title>Synth_SHELVE_CUTOFF</title>
|
|
<anchor id="mref-synth-shelve-cutoff" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_SHELVE_CUTOFF.png" format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_SHELVE_CUTOFF</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Filters out all frequencies over the cutoff frequency.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-brickwall-limiter-sect">
|
|
<title>Synth_BRICKWALL_LIMITER</title>
|
|
<anchor id="mref-synth-brickwall-limiter" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_BRICKWALL_LIMITER.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_BRICKWALL_LIMITER</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This modules clips a signal to make it fit into the range of [-1;1]. It
|
|
doesn't do anything to prevent the distortion that happens when clipping
|
|
loud signals. You can use this as effect (for instance to create a
|
|
slightly clipped sine wave). However, it's probably a good idea to run
|
|
the signal through a lowpass filter afterwards if you do so, to make it
|
|
sound less aggressive.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-std-equalizer-sect">
|
|
<title>Synth_STD_EQUALIZER</title>
|
|
<anchor id="mref-synth-std-equalizer" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_STD_EQUALIZER.png" format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_STD_EQUALIZER</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This is a nice parametric equalizer building block. It's parameters are:
|
|
</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term>invalue, outvalue</term>
|
|
<listitem>
|
|
<para>
|
|
The signal that gets filtered by the equalizer.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>low</term>
|
|
<listitem>
|
|
<para>
|
|
How low frequencies should be changed. The value is in dB, while 0 means
|
|
don't change low frequencies, -6 would mean take them out by 6dB, and +6
|
|
mean boost them by 6dB.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>mid</term>
|
|
<listitem>
|
|
<para>
|
|
How middle frequencies should be changed by the equalizer in dB (see
|
|
low).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>high</term>
|
|
<listitem>
|
|
<para>
|
|
How high frequencies should be changed by the equalizer in dB (see low).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>frequency</term>
|
|
<listitem>
|
|
<para>
|
|
This is the center frequency of the equalizer in Hz, the mid frequencies
|
|
are around that spectrum, the low and high frequencies below and above.
|
|
Note that the frequency may not be higher than half the sampling rate,
|
|
usually that is 22050 Hz, and not lower than 1 Hz.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>q</term>
|
|
<listitem>
|
|
<para>
|
|
This influences how broad the mid spectrum is. It must be be a positive
|
|
number > 0. A value of one is reasonable, higher values of q mean a
|
|
narrower spectrum of middle frequencies. Lower values than one mean a
|
|
broader spectrum.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-rc-sect">
|
|
<title>Synth_RC</title>
|
|
<anchor id="mref-synth-rc" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_RC.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_RC</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
A damped resonator filter filtering all frequencies around some peak
|
|
value. There is no useful way of specifying middle frequency (that
|
|
won't be cut), since the input are two strange constants f and b. The
|
|
code is very old, from the first days of the synthesizer, and will
|
|
probably replaced by a new filter which will have a frequency and a
|
|
resonance value as parameters.
|
|
</para>
|
|
|
|
<para>
|
|
Try something like b=5, f=5 or b=10, f=10 or b=15, f=15 though.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-moog-vcf-sect">
|
|
<title>Synth_MOOG_VCF</title>
|
|
<anchor id="mref-synth-moog-vcf" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_MOOG_VCF.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_MOOG_VCF</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Filters out all frequencies over the cutoff frequency (it's a 24db 4pole
|
|
filter, which filters -24db per octave above the cutoff frequency), but
|
|
offers an additional parameter for tuning the filter resonance, while 0
|
|
means no resonance and 4 means self oscillation.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-midi-sequencing">
|
|
<title>Midi + Sequencing</title>
|
|
|
|
<sect3 id="mref-synth-midi-test-sect">
|
|
<title>Synth_MIDI_TEST</title>
|
|
<anchor id="mref-synth-midi-test" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_MIDI_TEST.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_MIDI_TEST</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This modules loads an instrument structure from a file, and registers
|
|
itself as midi output with the &arts; &MIDI; manager. Notes sent to this
|
|
output will result in instrument voices being created.
|
|
</para>
|
|
|
|
<note>
|
|
<para>
|
|
You can setup something like this more convenient in &artscontrol; than
|
|
manually in &arts-builder;.
|
|
</para>
|
|
</note>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-sequence-sect">
|
|
<title>Synth_SEQUENCE</title>
|
|
<anchor id="mref-synth-sequence" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_SEQUENCE.png"
|
|
format="PNG" /></imageobject></mediaobject>
|
|
|
|
<para>
|
|
Will play a sequence of notes over and over again. The notes are given
|
|
in tracker notation, and are separated by semicolons. An example is
|
|
<literal>A-3;C-4;E-4;C-4;</literal>. The speed is given as seconds per
|
|
note, so if you want to get 120 bpm, you will probably specify 0.5
|
|
seconds/note, as 60 seconds/0.5 seconds per note=120 bpm.
|
|
</para>
|
|
|
|
<para>
|
|
You can give each note an length relative to the speed by using a colon
|
|
after the note and then then
|
|
length. <literal>A-3:2;C-4:0.5;D-4:0.5;E-4;</literal> demonstrates
|
|
this. As you see, midi composing programs tend to offer more comfort ;)
|
|
</para>
|
|
|
|
<para>
|
|
The Synth_SEQUENCE gives additional information about the
|
|
position of the note it is playing right now, while 0 means just started
|
|
and 1 means finished. This information you can use with
|
|
Synth_PSCALE (see below).
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-sequence-freq-sect">
|
|
<title>Synth_SEQUENCE_FREQ</title>
|
|
<anchor id="mref-synth-sequence-freq" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_SEQUENCE_FREQ.png"
|
|
format="PNG" /></imageobject></mediaobject>
|
|
|
|
<para>
|
|
This module works just like Synth_SEQUENCE with the only difference that
|
|
you don't write notenames but frequencies.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-samples">
|
|
<title>Samples</title>
|
|
|
|
<sect3 id="mref-synth-play-wav-sect">
|
|
<title>Synth_PLAY_WAV</title>
|
|
<anchor id="mref-synth-play-wav" />
|
|
|
|
<mediaobject>
|
|
<imageobject><imagedata fileref="images/Synth_PLAY_WAV.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_PLAY_WAV</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This will play a <literal role="extension">wav</literal> file. It will
|
|
only be present if you have libaudiofile on your computer. The wave file
|
|
will start as soon as the module gets created.
|
|
</para>
|
|
|
|
<para>
|
|
It will stop as soon as it's over, then finished will be set to 1. The
|
|
speed parameter can be used to replay the file faster or slower, where
|
|
1.0 is the normal (recorded) speed.
|
|
</para>
|
|
<!-- TODO: KDE2.2: check that this really works together in instruments with
|
|
the done parameter things ;) -->
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-soundio">
|
|
<title>Sound IO</title>
|
|
|
|
<sect3 id="mref-synth-play-sect">
|
|
<title>Synth_PLAY</title>
|
|
<anchor id="mref-synth-play" />
|
|
|
|
<mediaobject>
|
|
<imageobject><imagedata fileref="images/Synth_PLAY.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_PLAY</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<important>
|
|
<para>
|
|
You will normally not need this module, unless you are writing
|
|
standalone applications. Inside &artsd;, there normally is already a
|
|
Synth_PLAY module, and creating another one will not work.
|
|
</para>
|
|
</important>
|
|
|
|
<para>
|
|
The Synth_PLAY-module will output your audio signal to the
|
|
soundcard. The left and right channels should contain the
|
|
<emphasis>normalized</emphasis> input for the channels. If your input
|
|
is not between -1 and 1, you get clipping.
|
|
</para>
|
|
|
|
<para>
|
|
As already mentioned, there may only be one Synth_PLAY module
|
|
used, as this one directly accesses your soundcard. Use busses if you
|
|
want to mix more than one audio stream together before playing. Use the
|
|
Synth_AMAN_PLAY module to get something like an output
|
|
inside &artsd;.
|
|
</para>
|
|
|
|
<para>
|
|
Note that Synth_PLAY also does the timing of the whole
|
|
structure. This means: no Synth_PLAY = no source for timing = no
|
|
sound. So you absolutely need (exactly) one Synth_PLAY object.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-record-sect">
|
|
<title>Synth_RECORD</title>
|
|
<anchor id="mref-synth-record" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_RECORD.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_RECORD</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<important>
|
|
<para>You will normally not need this module, unless you are writing
|
|
standalone applications. Inside artsd, there normally is already a
|
|
Synth_RECORD module, and creating another one will not work.
|
|
</para>
|
|
</important>
|
|
|
|
<para>
|
|
The Synth_RECORD-module will record a signal from the soundcard.
|
|
The left and right channels will contain the input for the channels
|
|
(between -1 and 1).
|
|
</para>
|
|
|
|
<para>
|
|
As already mentioned, there may only be one Synth_RECORD module
|
|
used, as this one directly accesses your soundcard. Use busses if you
|
|
want to use the recorded audio stream in more than one place. Use the
|
|
Synth_AMAN_RECORD module to get something like an input
|
|
inside artsd. For this to work, &artsd; must run <emphasis>with full
|
|
duplex enabled </emphasis>.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-aman-play-sect">
|
|
<title>Synth_AMAN_PLAY</title>
|
|
<anchor id="mref-synth-aman-play" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_AMAN_PLAY.png"
|
|
format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_AMAN_PLAY</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
The Synth_AMAN_PLAY-module will output your audio signal.
|
|
It is nice (but not necessary) if you output a normalized signal
|
|
(between -1 and 1).
|
|
</para>
|
|
|
|
<para>
|
|
This module will use the audio manager to assign where the signal will
|
|
be played. The audio manager can be controlled through &artscontrol;. To
|
|
make it more intuitive to use, it is good to give the signal you play a
|
|
name. This can be achieved through setting
|
|
<emphasis>title</emphasis>. Another feature of the audio manager is to
|
|
be able to remember where you played a signal the last time. To do so it
|
|
needs to be able to distinguish signals. That is why you should assign
|
|
something unique to <emphasis>autoRestoreID</emphasis>, too.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-aman-record-sect">
|
|
<title>Synth_AMAN_RECORD</title>
|
|
<anchor id="mref-synth-aman-record" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_AMAN_RECORD.png" format="PNG"/></imageobject>
|
|
<textobject><phrase>Synth_AMAN_RECORD</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
The Synth_AMAN_RECORD-module will record an audio signal
|
|
from an external source (&ie;. line in/microphone) within &artsd;. The
|
|
output will be a normalized signal (between -1 and 1).
|
|
</para>
|
|
|
|
<para>
|
|
This module will use the audio manager to assign where the signal will
|
|
be played. The audio manager can be controlled through artscontrol. To
|
|
make it more intuitive to use, it is good to give the signal you record
|
|
a name. This can be achieved through setting
|
|
<emphasis>title</emphasis>. Another feature of the audio manager is to
|
|
be able to remember where you recorded a signal the last time. To do so
|
|
it needs to be able to distinguish signals. That is why you should
|
|
assign something unique to <emphasis>autoRestoreID</emphasis>, too.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-capture-sect">
|
|
<title>Synth_CAPTURE</title>
|
|
<anchor id="mref-synth-capture" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_CAPTURE.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_CAPTURE</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
The Synth_CAPTURE-module will write an audio signal to a wave
|
|
file on your hard disc. The file will always be called
|
|
<filename>/tmp/mcop-<replaceable>usename</replaceable>/capture.wav</filename>
|
|
</para>
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-tests">
|
|
<title>Tests</title>
|
|
|
|
<sect3 id="mref-synth-nil-sect">
|
|
<title>Synth_NIL</title>
|
|
<anchor id="mref-synth-nil" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_NIL.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_NIL</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This just does nothing. It is only useful for test situations.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-debug-sect">
|
|
<title>Synth_DEBUG</title>
|
|
<anchor id="mref-synth-debug" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_DEBUG.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_DEBUG</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
You can use this for debugging. It will print out the value of the
|
|
signal at invalue in regular intervals (ca. 1 second), combined with the
|
|
comment you have specified. That way you can find out if some signals
|
|
stay in certain ranges, or if they are there at all.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-midi-debug-sect">
|
|
<title>Synth_MIDI_DEBUG</title>
|
|
<anchor id="mref-synth-midi-debug" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_MIDI_DEBUG.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_MIDI_DEBUG</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
You can use this to debug how your &MIDI; events are actually arriving
|
|
in &arts;.
|
|
</para>
|
|
|
|
<para>
|
|
When a MIDI_DEBUG is running &artsserver; will print out a lines
|
|
like:
|
|
</para>
|
|
|
|
<screen><computeroutput>201 100753.837585 on 0 42 127</computeroutput></screen>
|
|
|
|
<screen><computeroutput>202 101323.128355 off 0 42</computeroutput></screen>
|
|
|
|
<para>
|
|
While the first line would be telling you that 100753ms (that is 100
|
|
seconds) after the MIDI_DEBUG started, a &MIDI; on event arrived
|
|
on channel 0. This midi on event had the velocity (volume) of 127, the
|
|
loudest possible. The next line shows the midi release event. [ TODO:
|
|
this does not work currently, make it work, and do it via &MIDI; manager
|
|
].
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-data-sect">
|
|
<title>Synth_DATA</title>
|
|
<anchor id="mref-synth-data" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_DATA.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_DATA</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This creates a signal with a constant number.
|
|
</para>
|
|
<!-- TODO: this doesn't really belong in test, does it? -->
|
|
</sect3>
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-osc-mod">
|
|
<title>Oscillation & Modulation</title>
|
|
|
|
<sect3 id="mref-synth-frequency-sect">
|
|
<title>Synth_FREQUENCY</title>
|
|
<anchor id="mref-synth-frequency" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_FREQUENCY.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_FREQUENCY</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
All oscillators in &arts; don't require a frequency as input, but a
|
|
position in the wave. The position should be between 0 and 1, which maps
|
|
for a standard Synth_WAVE_SIN object to the range
|
|
0..2*pi. To generate oscillating values from a frequency, a
|
|
Synth_FREQUENCY modules is used.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-fm-source-sect">
|
|
<title>Synth_FM_SOURCE</title>
|
|
<anchor id="mref-synth-fm-source" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_FM_SOURCE.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_FM_SOURCE</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
This is used for frequency modulation. Put your frequency to the
|
|
frequency input and put another signal on the modulator input. Then set
|
|
modlevel to something, say 0.3. The frequency will be modulated with
|
|
modulator then. Just try it. Works nice when you put a feedback in
|
|
there, that means take a combination of the delayed output signal from
|
|
the Synth_FM_SOURCE (you need to put it to some oscillator
|
|
as it only takes the role of Synth_FREQUENCY) and some other
|
|
signal to get good results.
|
|
</para>
|
|
|
|
<para>
|
|
Works nicely in combination with Synth_WAVE_SIN
|
|
oscillators.
|
|
</para>
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="mcat-synth-waveforms">
|
|
<title>Wave Forms</title>
|
|
|
|
<sect3 id="mref-synth-wave-sin-sect">
|
|
<title>Synth_WAVE_SIN</title>
|
|
<anchor id="mref-synth-wave-sin" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_WAVE_SIN.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_WAVE_SIN</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Sinus oscillator. Put a pos signal from Synth_FREQUENCY or
|
|
Synth_FM_SOURCE at the input. And get a sinus wave as
|
|
output. The pos signal specifies the position in the wave, the range
|
|
0..1 is mapped to 0..2*pi internally.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-wave-tri-sect">
|
|
<title>Synth_WAVE_TRI</title>
|
|
<anchor id="mref-synth-wave-tri" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_WAVE_TRI.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_WAVE_TRI</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Triangle oscillator. Put a pos signal from Synth_FREQUENCY or
|
|
Synth_FM_SOURCE at the input. And get a triangle wave as
|
|
output. The pos signal specifies the position in the wave, the range
|
|
0..1 is mapped to 0..2*pi internally. Be careful. The input signal
|
|
<emphasis>must</emphasis> be in the range 0..1 for the output signal to
|
|
produce good results.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-noise-sect">
|
|
<title>Synth_NOISE</title>
|
|
<anchor id="mref-synth-noise" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_NOISE.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_NOISE</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Noise generator. This generates a random signal between -1 and 1.
|
|
</para>
|
|
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-wave-square-sect">
|
|
<title>Synth_WAVE_SQUARE</title>
|
|
<anchor id="mref-synth-wave-square" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_WAVE_SQUARE.png" format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_WAVE_SQUARE</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Square oscillator. Put a pos signal from Synth_FREQUENCY or
|
|
Synth_FM_SOURCE at the input. And get a square wave as
|
|
output. The pos signal specifies the position in the wave, the range
|
|
0..1 is mapped to 0..2*pi internally. Be careful. The input signal
|
|
<emphasis>must</emphasis> be in the range 0..1 for the output signal to
|
|
produce good results.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-wave-softsaw-sect">
|
|
<title>Synth_WAVE_SOFTSAW</title>
|
|
<anchor id="mref-synth-wave-softsaw" />
|
|
|
|
<mediaobject><imageobject><imagedata
|
|
fileref="images/Synth_WAVE_SOFTSAW.png" format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_WAVE_SOFTSAW</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Softened saw wave, similar in look like the Synth_WAVE_TRI
|
|
oscillator. Put a pos signal from Synth_FREQUENCY or
|
|
Synth_FM_SOURCE at the input. You'll get a softened saw
|
|
wave as output. The pos signal specifies the position in the wave, the
|
|
range 0..1 is mapped to 0..2*pi internally. Be careful. The input signal
|
|
<emphasis>must</emphasis> be in the range 0..1 for the output signal to
|
|
produce good results.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="mref-synth-wave-pulse-sect">
|
|
<title>Synth_WAVE_PULSE</title>
|
|
<anchor id="mref-synth-wave-pulse" />
|
|
|
|
<mediaobject><imageobject><imagedata fileref="images/Synth_WAVE_PULSE.png"
|
|
format="PNG" /></imageobject>
|
|
<textobject><phrase>Synth_WAVE_PULSE</phrase></textobject>
|
|
</mediaobject>
|
|
|
|
<para>
|
|
Pulse oscillator - this module is similar in spirit like the rectangular
|
|
oscillator (Synth_WAVE_RECT), but it provides a configurable up/down
|
|
ratio, through the <emphasis>dutycycle</emphasis> parameter. Put a pos
|
|
signal from Synth_FREQUENCY or Synth_FM_SOURCE at
|
|
the input. Get a pulse wave as output. The pos signal specifies the
|
|
position in the wave, the range 0..1 is mapped to 0..2*pi internally. Be
|
|
careful. The input signal <emphasis>must</emphasis> be in the range 0..1
|
|
for the output signal to produce good results.
|
|
</para>
|
|
</sect3>
|
|
</sect2>
|
|
<sect2 id="mcat-synth-misc">
|
|
<title>Miscellaneous</title>
|
|
|
|
<sect3 id="mref-synth-compressor-sect">
|
|
<title>Synth_COMPRESSOR</title>
|
|
<anchor id="mref-synth-compressor" />
|
|
|
|
<mediaobject>
|
|
<imageobject><imagedata fileref="images/Synth_COMPRESSOR.png"
|
|
format="PNG"/></imageobject></mediaobject>
|
|
|
|
<para>
|
|
This module reduces the dynamic range of the signal. For example
|
|
compressors are useful in compensating for the wide variations in
|
|
loudness of somebody talking into a microphone.
|
|
</para>
|
|
|
|
<para>
|
|
As soon as the input level exceeds a certain level (the threshold)
|
|
the signal gets compressed. It simply multiplies everything above
|
|
the threshold with the ratio, which should be a number between 0 and
|
|
1. Finally the whole signal is multiplied by the output factor.
|
|
</para>
|
|
|
|
<para>
|
|
The attack and release arguments delay the start and end of the
|
|
compression. Use this if you, for example, still want to hear the
|
|
loud beginning of a basedrum. The argument is in milliseconds and an
|
|
attack or release of 0ms is possible but may result in a slight noise.
|
|
</para>
|
|
|
|
</sect3>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="visual-modules-reference">
|
|
<title>Visual Modules Reference</title>
|
|
|
|
<para>
|
|
TODO when visual modules are more "finished".
|
|
</para>
|
|
</sect1>
|
|
|
|
</chapter>
|