zynaddsubfx

ZynAddSubFX open source synthesizer
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envelope.txt (4424B)

      1 Envelopes
      2 ---------
      3 
      4 Introduction
      5 ~~~~~~~~~~~~
      6 Envelopes control how the amplitude, the frequency, or the
      7 filter changes over time.
      8 
      9 Amplitude Envelopes
     10 ~~~~~~~~~~~~~~~~~~~
     11 
     12 These envelopes controls the amplitude of the sound.
     13 In ZynAddSubFX, amplitude envelopes can be linear or logarithmic. 
     14 In the next image, it is shown the differences between these envelopes. 
     15 
     16 image::images/envelope1.png[Alt text]
     17 
     18 The amplitude envelope is divided into:
     19 
     20 * *Attack*: Begins at the Note On. The volume starts from 0 to the maximum.
     21 In ZynAddSubFX, the attack is always linear.
     22 * *Decay*: The volume drops from the maximum value to a level called "Sustain level"
     23 * *Sustain*: The volume remains constant until the key is depressed (Note Off).
     24 After this, the last stage take place.
     25 * *Release*: The volume drops to zero
     26 
     27 
     28 Frequency Envelopes
     29 ~~~~~~~~~~~~~~~~~~~
     30 
     31 These envelopes controls the frequency (more exactly, the pitch) of
     32 the oscillators.
     33 The following picture draws the stages of these envelopes.
     34 
     35 image::images/envelope2.png[Alt text]
     36 
     37 The dotted line represents the real pitch of the sound without the
     38 envelope.
     39 
     40 The frequency envelopes are divided into 3 stages:
     41 
     42 * *Attack*: Begins at the Note On. The frequency starts from a certain value and
     43 glides to the real frequency of the note.
     44 * *Sustain*: The frequency is the same on over the sustain period 
     45 * *Release*: This stage begins on Note Off and glides the frequency of the note
     46 to a certain
     47 value
     48 
     49 Filter Envelopes
     50 ~~~~~~~~~~~~~~~~
     51 These envelopes controls the cutoff frequency of the filters and are divided
     52 into
     53 
     54 image:images/envelope3.png[Alt Text]
     55 
     56 * *Attack*: Begins at the Note On. The cutoff frequency starts from a certain value and glides to another value
     57 * *Decay*: The cutoff frequency continues to glide to the real cutoff frequency value of the filter (dotted line)
     58 * *Sustain*: the cutoff frequency is the same on over the sustain period (dotted line)
     59 * *Release*: this stage begins on Note Off and glides the filter cutoff frequency of the note to a certain value 
     60 
     61 Freemode Envelopes
     62 ~~~~~~~~~~~~~~~~~~
     63 
     64 For all envelope there is a mode that allows the user to set an arbitrary number of stages and control points. This mode is called Freemode.
     65 
     66 image:images/envelope4.png[Alt Text]
     67 
     68 Only stage that always remains defined is the Sustain, where the envelopes freezes until a Note Off event.
     69 
     70 User Interface
     71 ~~~~~~~~~~~~~~
     72 All the envelope types has some common controls:
     73 
     74 * *E*: Shows a window that you can view the real envelope shape or convert to free mode to edit it
     75 * *Stretch*: How the envelope is stretched according the note.
     76 On the higher notes the envelopes are shorter than lower notes.
     77 In the leftmost value, the stretch is zero.
     78 The rightmost use a stretch of 200%; this means that the envelope is stretched about 4 times/octave.
     79 * *frcR*: Forced release.
     80 This means that if this option is turned on, the release will go to the final value, even if the sustain stage is not reached. Usually, this must be set.
     81 
     82 
     83 The parameters for Amplitude Envelopes for ZynAddSubFX are:
     84 
     85 image:images/uienvelope3.jpg[Alt Text]
     86 
     87 * *A.dt*: Attack duration
     88 * *D.dt*: Decay duration
     89 * *S.Val*: Sustain value
     90 * *R.dt*: Release time
     91 * *L*: If this option is set, the envelope is linear, otherwise, it will be
     92 logarithmic
     93 
     94 
     95 For Frequency Envelopes the interface has the following parameters:
     96 
     97 image:images/uienvelope2.jpg[Alt Text]
     98 
     99 * *A.val*: Attack value
    100 * *A.dt*: Attack duration
    101 * *R.dt*: Release time
    102 * *R.val*: Release value
    103 
    104 
    105 Filter Envelopes has the parameters:
    106 
    107 image:images/uienvelope1.jpg[Alt Text]
    108 
    109 * *A.val*: Attack value
    110 * *A.dt*: Attack duration
    111 * *D.val*: Decay value
    112 * *D.dt*: Decay time
    113 * *R.dt*: Release time
    114 * *R.val*: Release value
    115 
    116 The Freemode envelopes has a separate window to set the parameters and controls:
    117 
    118 image:images/uienvelope0.jpg[]
    119 
    120 *  *Control points*: You can move the points using the mouse.
    121 In the right on the windows, it is shown the total duration of the envelope.
    122 If the mouse button will be pressed on a control point, it will be shown the
    123 duration of the stage where the point is.
    124 * *FreeMode*: this button activates or deactivates the freemode mode.
    125 * *Add Point*: Adds the point next to the current selected point.
    126 You can select a point by clicking on it.
    127 * *Delete point*: Removes the point from the envelope.
    128 * *Sust.*: Set the sustain point. It is shown using the yellow line.
    129 * *Str.*: Envelope stretch
    130 
    131