Programmer Guide/Macro Library/BSeq: Difference between revisions

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The class <code>BSeq</code> can create and play sequences and provides an interface to the [[Programmer_Guide/Shell_Items/Wave/SET_WAVE#sequence wave-item]] functions.  
The class <code>BSeq</code> can create and play sequences and provides an interface to the [[Programmer_Guide/Shell_Items/Wave/SET_WAVE#sequence wave-item]] functions.  


==Create a new Instance of BSeq==
==Create an Instance of BSeq==
;Usage:  
;Usage:  
:<code>bseq [ <var>attr</var>=<var>value</var> ; ... ]</code>
:<code>bseq [ <var>attr</var>=<var>value</var> ; ... ]</code>
Line 11: Line 11:
:;<var>attr</var>=<var>value</var>, ...: initial values for sequence attributes (see member function [[/Set_Attributes|Set]])
:;<var>attr</var>=<var>value</var>, ...: initial values for sequence attributes (see member function [[/Set_Attributes|Set]])
;Result: An instance of BSeq or an empty string
;Result: An instance of BSeq or an empty string
;Description: Create and initialize a sequence instance and assign sequence attributes. To assign the attribute(s) the member function [[/#Set_Attributes|Set]] is called.
;Description: Create and initialize a sequence instance and assign sequence attributes. To assign the attribute(s) the member function [[/#Set_Attributes|Set]] is called. In the descriptions of the member functions the first argument <var>bseq_instance</var> is an instance of the class BSeq created by this function.


==Set Attributes==
==Set Attributes==
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:* <code>table</code> &rarr; get signal definition table
:* <code>table</code> &rarr; get signal definition table


===Signal===
==Define Sequence Signals==
 
===Add Signal===
;Usage: <code><var>bseq_instance</var> signal <var>ch ; base ; time ; sigtype ; sigpars</var></code>
;Usage: <code><var>bseq_instance</var> signal <var>ch ; base ; time ; sigtype ; sigpars</var></code>
:;<var>ch</var>: sequence channel number (1, 2, ..), '''0''' or '''*''' for all channels
:;<var>ch</var>: sequence channel number (1, 2, ..), '''0''' or '''*''' for all channels
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| A triangle function with a duration of <var>d</var> seconds, an amplitude <var>a</var>, a frequency <var>f</var> Hz and a duty cycle <var>q</var> (0 &lt; <var>q</var> &lt; 1).
| A triangle function with a duration of <var>d</var> seconds, an amplitude <var>a</var>, a frequency <var>f</var> Hz and a duty cycle <var>q</var> (0 &lt; <var>q</var> &lt; 1).
|-
|-
| '''tone''' || <var>d ; a ; f ; p ; n ; da ; df</var> || A sine wave or a harmonic tone with a duration of <var>d</var> seconds, an amplitude <var>a</var>, a frequency <var>f</var> Hz and a phase <var>p</var> rad. If the number of harmonics <var>n</var> is greater than one, the values <var>da</var> (def.=1) and <var>df</var> (def.=<var>f</var>) are used to compute the amplitude and frequency of component ''i'' (= 1..<var>n</var>):<br/>ai = <var>a</var> . <var>da</var><sup>''i-1''</sup>; fi = <var>df</var> +</code> <var>f</var> . (''i''-1)
| '''tone''' || <var>d ; a ; f ; p ; n ; da ; df</var> || A sine wave or a harmonic tone with a duration of <var>d</var> seconds, an amplitude <var>a</var>, a frequency <var>f</var> Hz and a phase <var>p</var> rad. If the number of harmonics <var>n</var> is greater than one, the values <var>da</var> (def.=1) and <var>df</var> (def.=<var>f</var>) are used to compute the amplitude and frequency of component ''i'' (= 1..<var>n</var>):<br/>a''i'' = <var>a</var> . <var>da</var><sup>''i-1''</sup>; f''i'' = <var>df</var> + <var>f</var> . (''i''-1)
|-  
|-  
| '''segment''' || <var>aset ; aseg ; ach ; a</var>  
| '''segment''' || <var>aset ; aseg ; ach ; a</var>  
Line 71: Line 73:
|}
|}


;Notes:
* Gaps are filled with zero (pause). This means, all regions of a sequence, where no signal is assigned are implicit set to pause.
* Signals which are overlapping in time are mixed (added).
* The member functions [[/#Assign_Envelope|envelope]], [[/#Assign_Envelope|filter]], [[/#Assign_Frq-Modulation|fmod]] and [[/#Assign_Amp-Modulation|amod]] can be used to apply special processing to a defined signal.


===Delete Signal===
;Usage: <code><var>bseq_instance</var> delete <var>pos</var></code>
.;<var>pos</var>: the index of the signal; '''*''' for the last defined signal
;Result: always '''0'''
;Description: Delete the specified signal defintion from the sequence.


===Assign Envelope===
;Usage: <code><var>bseq_instance</var> envelope <var>pos ; type ; t1 a1 t2 a2 ...</code>
:;<var>pos</var>: the signal index; '''*''' for last defined signal
:;<var>type</var>: the type of envelope. The types '''none''' (no envelope), '''linear''' and '''cosine''' are supported
:;<var>tX aX</var>: the envelope points; each point is defined by a time <var>tX</var> (in seconds) and an amplitude factor <var>aX</var>.
;Result: '''0''' for success and a non-zero value if failed
;Description: Define an envelope function for the signal <var>pos</var>. An envelope is defined by the function <var>type</var> and a set of points, each one defined with a time and an amplitude value (<var>tX</var> and <var>aX</var>). The time values can be specified as an offset from the beginning (<var>tX</var> &gt; <code>0</code>) or from the end (<var>tX</var> &lt <code>0</code>). If no point at the begin/end of the signal is defined a begin/end  point with amplitude '''0''' is automatically added (&rarr; the signal starts/ends with zero amplitude).<br/>If the argument <var>type</var> is set to '''none''' the envelope function for the signal <var>pos</var> is cleared.


===Assign Filter===
;Usage: <code><var>bseq_instance</var> filter <var>pos ; type ; f1 ; f2 ; inv ; order ; damp ; ripple</var></code>
:;<var>pos</var>: the signal index; '''*''' for last defined signal
:;<var>type</var>: the type of filter. The filter types '''none''' (no filter), '''elliptic''', '''butterworth''' and '''chebychev''' are supported
:;<var>f1, f2: the frequency band in Hz
:;<var>inv</var>: if set to '''yes''' (or '''1''') the frequency response is inverted, otherwise ('''no''' or '''0''') not.
:;<var>order</var>: the filter order; this must be must an integer greater than '''1''' (default=5)
:;<var>damp</var>: the stopband damping in dB; <var>damp</var> &ge; 10 (default=60)
;<var>ripple</var>: the passband ripple in dB; 0 &lt; <var>ripple</var> &le; 10 (default=1)
;Result: '''0''' for success and a non-zero value if failed
;Description: Define a filter for the signal <var>pos</var>. The filter applied to the signal is an IIR filter of the specified type. The arguments <var>f1</var>, <var>f2</var> and <var>inv</var> define the passband/stopband of the filter (see below). The parameters <var>order</var>, <var>damp</var> and <var>ripple</var> define the damping, the passband linearity and the slopes.).<br/>If the argument <var>type</var> is set to '''none''' the filter for the signal <var>pos</var> is cleared.


Filter types (with: ''fmax'' = half sampling rate):
:* <var>f1</var> = 0, <var>f2</var> > 0, <var>inv</var> = 0 &rarr; lowpass
:* <var>f1</var> > 0, <var>f2</var> = ''fmax'', <var>inv</var> = 0 &rarr; highpass
:* 0 < <var>f1</var> < <var>f2</var> < ''fmax'', <var>inv</var> = 0 &rarr; bandpass
:* 0 < <var>f1</var> < <var>f2</var> < ''fmax'', <var>inv</var> = 1 &rarr; bandstop (notch)


===Assign Frq-Modulation===
;Usage:
:<code><var>bseq_instance</var> fmod <var>pos</var> ; none</code>
:<code><var>bseq_instance</var> fmod <var>pos</var> ; sine ; <var>rate ; bw ; p</var></code>
:<code><var>bseq_instance</var> fmod <var>pos</var> ; rectangle|triangle ; <var>rate ; bw ; dc</var></code>
:<code><var>bseq_instance</var> fmod <var>pos</var> ; sweep ; <var>w ; k</var></code>
;:<var>rate, bw</var>: modulation rate and bandwidth in Hz
;:<var>p</var>: starting phase of '''sine''' modulation in rad (default=0)
;:<var>dc</var>: duty cycle factor '''rectangle''' and '''triangle''' modulation (0 < <var>dc</var> < 1, default=0.5)
;:<var>w, k</var>: width (<var>w</var>, in Hz) and exponent (<var>k</var>, &ge; 0) for '''sweep''' function
;Result: '''0''' for success and a non-zero value if failed
;Description: Define a frequency modulation or a sweep function for the signal <var>pos</var>. Modulating frequency makes only sense for periodic signal generators (e.g. rectangle, triangle or tone).<br/>If the keyword '''none''' is used, the frq-modulation for the signal <var>pos</var> is cleared.


:Computation of frequency modulation:
::f(t) = ''f'' + <var>bw</var>/2 . m(t)
::* ''f'': the frequency assigned to the signal generator (carrier)
::* <var>bw</<var>: the modulation bandwidth in Hz (> 0)
::* m(t): the modulation function (depends on selected function type, <var>rate</var> and <var>p|dc</var>)
::* f(t): modulated frequency at time t


:Computation of sweep function:
::linear sweep if <var>k</var> = 0: f(t) = ''f'' + <var>w</var> . t / ''d''
::exponential sweep if <var>k</var> > 0: f(t) = f + <var>w</var> . (t / ''d'')<sup><var>k</var></sup>
::* ''f'': the frequency assigned to the signal generator (carrier)
::* ''d'': the duration assigned to the signal generator
::* <var>w</<var>: the sweep width (in Hz, &ne; 0)
::* <var>k</<var>: the sweep exponent (&ge; 0)
::* f(t): sweep frequency at time t


 
===Assign Amp-Modulation===
 
====BSeq Member Functions====
 
The <code>BSeq</code> class has the following member functions. See CObj Member Functions for a list of functions implemented in the parent class.
 
===AMod===
 
Define/undefine an amplitude modulation function for the signal pos. The amplitude modulation is computed as follows:
 
y(t) = ((1 – fac/2) + m(t).fac/2) . x(t)
 
with:
 
{|
|-
|y(t)
|modulated sequence signal
|-
|x(t)
|sequence signal
|-
|m(t)
|modulation function, depends on type, rate and dc or phase
|-
|fac
|modulation factor (0 <= fac <= 1)
|}
 
=====Usage:=====
 
<code>inst AMod <var>pos</var> ; <var>type</var> ; <var>rate</var> ; <var>factor</var> ; <var>dc</var>|<var>phase</var></code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:The signal index (* for the last defined signal).
 
;<var>type</var>
 
:The type of modulation function. The following types are supported:
 
:<code>none</code>|<code>rectangular</code>|<code>triangle</code>|<code>sine</code>
 
;<var>rate</var>
 
:The modulation rate in Hz.
 
;<var>factor</var>
 
:The modulation factor.
 
;<var>dc</var>
 
:The duty cycle (if the <var>type</var> is <code>rectangular</code> or <code>triangle</code>).
 
;<var>phase</var>
 
:The starting phase (if the <var>type</var> is <code>sine</code>).
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed
 
=====Parameters:=====
 
;<var>attr</var>
 
:The name of the sequence attribute.
 
;<var>value</var>
 
:The value of the sequence attribute.
 
=====Result:=====
 
0 for success and 1 for error
 
Note that you can create an instance of the <code>BSeq</code> class with the following syntax:
 
<code>#inst := BSeq</code>
 
===Copy===
 
Copies the sequence signal to the specified target. To perform the copy function the class [[Programmer Guide/Class Library/BSignal|BSIGNAL]] is used.
 
=====Usage:=====
 
<code><var>inst</var> Copy <var>mode</var> ; <var>sch</var> ; <var>tset</var> ; <var>tseg</var> ; <var>tch</var> ; <var>tmode</var> ; <var>tname</var></code>
 
=====Parameters:=====
 
;<var>mode</var>
 
:This parameter is currently not used, but is reserved for future expansions.
 
;<var>sch</var>
 
:The sequence channel list (see <code>CreateWave</code>).
 
;<var>tset</var>
 
:The target audio set.
 
;<var>tseg</var>
 
:The target segment reference, id or expression.
 
;<var>tch</var>
 
:The target channel.
 
;<var>tmode</var>
 
:The target mode. The following values are supported:
 
:<code>insert</code>|<code>replace</code>|<code>mix</code>
 
;<var>tname</var>
 
:The name for the copied signal.
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
===CreateSegments===
 
Creates audio segments (<code>ASeg</code> elements) for all defined signals and stores them in the specified DataSet element. Also a segment named <code>Signal.All</code> for the whole sequence signal is created. The segment names are chosen automatically.
 
=====Usage:=====
 
<code><var>inst</var> CreateSegments <var>ref</var></code>
 
=====Parameters:=====
 
;<var>ref</var>
 
:The reference to a DataSet element of type <code>ASequence</code>.
 
=====Result:=====
 
The number of created segments.
 
===CreateWave===
 
Creates the sequence wave item and prepares it for use. If create succeeds the wave item is returned and can be used for signal processing. Otherwise the error information is written to the log. window and an empty string is returned. If a channel list argument is specified only the requested channels are created. If the definition contains signals of type segment, the sound files are opened automatically before the wave item is created. The returned wave item must be deleted with the member function <code>DeleteWave</code> and not with the command '<code>delete waveitem</code>'!
 
=====Usage:=====
 
<code><var>inst</var> CreateWave [ <var>sch</var> ]</code>
 
=====Parameters:=====
 
;<var>sch</var>
 
:The sequence channel list (blank separated list of channel indices).
 
=====Result:=====
 
The name of the created sequence wave item or empty string if creation fails.
 
===Delete===
 
Delete the signal pos from the sequence.
 
=====Usage:=====
 
<code><var>inst</var> Delete <var>pos</var></code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:The signal index (<code>*</code> for the last defined signal).
 
=====Result:=====
 
Always <code>0</code>.
 
===DeleteWave===
 
Deletes the sequence wave item created with <code>CreateWave</code> and closes all sound files opened during creation.
 
=====Result:=====
 
Always <code>0</code>.
 
===Destruct===
 
Remove sequence and sequence wave item (if created).
 
=====Result:=====
 
none
 
===DialogEdit===
 
Displays a dialog to add, modify and delete signal definitions.
 
=====Result:=====
 
none
 
===DialogSetup===
 
Displays a dialog to change the sequence attributes.
 
=====Result:=====
 
<code>0</code> for OK and <code>1</code> for cancel.
 
===Envelope===
 
Define/undefine an envelope function for the signal <var>pos</var>. An envelope is defined by the function <var>type</var> and a set of points, each one defined with a time and an amplitude value (<var>tX</var> and <var>aX</var>). The time values can be specified as an offset from the beginning (<var>tX</var> > <code>0</code>) or from the end (<var>tX</var> < <code>0</code>). If an amplitude is defined, the signal starts and ends with a zero amplitude.
 
=====Usage:=====
 
<code><var>inst</var> Envelope <var>pos</var> ; <var>type</var> ; <var>t1</var> <var>a1</var> <var>t2</var> <var>a2</var> ...</code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:The signal index (<code>*</code> for last defined signal).
 
;<var>type</var>
 
:The type of envelope. The following values are supported:
 
:<code>none</code>|<code>linear</code>|<code>cosine</code>
 
;<var>tX,aX</var>
 
:The envelope points (<var>tX</var> = time in seconds, <var>aX</var> = linear amplitude).
 
=====result:=====
 
0 for success and a non-zero value if failed
 
===Filter===
 
Define or undefine a filter for the signal <var>pos</var>. The filter applied to the signal is an IIR filter of the specified type. The arguments <var>f1</var>, <var>f2</var> and <var>inv</var> define the frequency band and filter type:
 
f1 = 0, f2 > 0, inv = 0 // lowpass
f1 > 0, f2 = samplingrate / 2, inv = 0 // highpass
0 < f1 < f2 < samplingrate / 2, inv = 0 // bandpass
0 < f1 < f2 < samplingrate / 2, inv = 1 // bandstop
 
The parameters <var>order</var>, <var>damp</var> and <var>ripple</var> are used for the coefficient computation.
 
=====Usage:=====
 
<code><var>inst</var> Filter <var>pos</var> ; <var>type</var> ; <var>f1</var> ; <var>f2</var> ; <var>inv</var> ; <var>order</var> ; <var>damp</var> ; <var>ripple</var></code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:The signal index (<code>*</code> for the last defined signal).
 
;<var>type</var>
 
:The type of filter. The following values are supported:
 
:<code>none</code>|<code>elliptic</code>|<code>butterworth</code>|<code>chebychev</code>
 
;<var>f1,f2</var>
 
:The frequency band.
 
;<var>inv</var>
 
:Invert - <code>yes</code>|<code>no</code>, <code>0</code>|<code>1</code>
 
;<var>order</var>
 
:The filter order must be an integer greater than <code>1</code>. The default is <code>5</code>.
 
;<var>damp</var>
 
:The stopband damping in dB must be a number less than <code>-9</code> or greater than <code>9</code>. The default is <code>60</code>.
 
;<var>ripple</var>
 
:The passband ripple in dB must be a number between <code>-10</code> and <code>10</code>. The default is <code>1</code>.
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
===FMod===
 
Define or undefine a frequency modulation function for the signal <var>pos</var>. A frequency modulation can only be defined for signal generators which generates a periodic signal (e.g. rectangle, triangle or tone). The frequency modulation is computed as follows:
 
f(t) = f + bw/2.m(t)
 
with:
 
{|
|-
|fc
|the fundamental frequency of the generator (carrier)
|-
|f(t)
|modulated frequency
|-
|m(t)
|modulation function, depends on type, rate and dc or phase
|-
|bw
|modulation bandwidth in Hz (>0)
|}
 
=====Usage:=====
 
<code>inst FMod <var>pos</var> ; <var>type</var> ; <var>rate</var> ; <var>bw</var> ; <var>dc</var> ; <var>phase</var></code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:The signal index (<code>*</code> for the last defined signal).
 
;<var>type</var>
 
:The type of modulation function. The following values are supported:
 
:<code>none</code>|<code>rectangle</code>|<code>triangle</code>|<code>sine</code>
 
;<var>rate</var>
 
:The modulation rate in Hz.
 
;<var>bw</var>
 
:The modulation bandwidth in Hz.
 
;<var>dc</var>
 
:The duty cycle (if <var>type</var> is <code>rectangle</code> or <code>triangle</code>).
 
;<var>phase</var>
 
:The starting phase (if <var>type</var> is <code>sine</code>).
 
=====Result:=====
 
0 for success and a non-zero value if failed
 
Define or undefine an frequency sweep function for the signal <var>pos</var>. A sweep can only defined for signal generators which generates a periodic signal (e.g. rectangle, triangle or tone). The sweep is computed as follows:
 
for exp = 0: f(t) = f + width . t / d
for exp > 0: f(t) = f + width . (t / d)exp
 
with:
 
{|
|-
|fc
|fundamental frequency of the generator (carrier)
|-
|f(t)
|modulated frequency
|-
|width
|sweep width in Hz (any number)
|-
|exp
|sweep function exponent
|-
|d
|signal duration
|}
 
=====Usage:=====
 
<code>inst FMod <var>pos</var> ; SWEEP ; <var>width</var> ; <var>exp</var></code>
 
=====Parameters:=====
 
;<var>pos</var>
 
:See above
 
;<var>width</var>
 
:The sweep width in Hz (positive and negative values are allowed).
 
;<var>exp</var>
 
:The sweep function exponent (>= 0).
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
 
===Load===
 
Loads the signal definitions from child element ASequenceSignals of the specified DataSet element. The signal definition table is cleared before the element is loaded.
 
=====Usage:=====
 
<code><var>inst</var> Load <var>ref</var></code>
 
=====Parameters:=====
 
;<var>ref</var>
 
:The reference to a DataSet element containing a sequence signal definition element with tag <code>ASequenceSignals</code>.
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
===Play===
 
Plays the sequence. The class <code>PlayWave</code> is used for playback.
 
=====Usage:=====
 
<code><var>inst</var> Play <var>dialog</var> [; <var>sch</var> ]</code>
 
=====Parameters:=====
 
;<var>dialog</var>
 
:Display a play dialog or play without a dialog. The following values are supported:
 
:<code>0</code> - do not display a dialog
 
:<code>1</code> - display a dialog
 
;<var>sch</var>
 
:The sequence channel list (see CreateWave).
 
=====Result:=====
 
0 for success and a non-zero value if failed
 
===Save===
 
Stores the signal definitions in the child element <code>ASequenceSignals</code> of the specified DataSet element.
 
=====Usage:=====
 
<code><var>inst</var> Save <var>ref</var></code>
 
=====Parameters:=====
 
;<var>ref</var>
 
:The reference to a DataSet element.
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
 
 
===Test===
 
Test the sequence definition. Returns 0 if the definitions are valid and the sequence wave item can be created. For a description of the channel index arguments see function CreateWave.
 
=====Usage:=====
 
<code><var>inst</var> Test [ <var>sch</var> ]</code>
 
=====Parameters:=====
 
;<var>sch</var>
 
:The sequence channel list (see <code>CreateWave</code>).
 
=====Result:=====
 
<code>0</code> for success and a non-zero value if failed.
 
====Examples====
 
<pre>
//{{3.8 3219}{2007.08.14  15.05.47} - automatically created version information - do not change or delete this line}
///////////////////////////////////////////////////////////////////////////////
//
//  Macro:          bseq_examples
//  Description:    Playback a sine tone at 1000Hz using the BSeq class.
//  Parameters:    none
//  Return:        0 on success
//  Author:        Jonnie White
//  History:        2007-08-14  created
//  File:          bseq_examples.sts
//
///////////////////////////////////////////////////////////////////////////////
[Macro bseq_example]
 
// create a BSeq instance
#bseq := BSeq
if '$#bseq[?]' != 'instance' em -1 ; $#mac::Error - failed to create a BSeq instance
// define a 100s sine tone at 1000Hz
$#bseq Signal * ; begin ; 0 ; tone ; 100 ; 1 ; 1000 ; 0
if '$result' != 0 em $result ; $#mac::Error - sequence Signal call failed
// play the tone using the playback dialog
$#bseq play 1
if '$result' != 0 em $result ; $#mac::Error - playback failed
// destroy the instance
$#bseq destroy
 
exit 1 int 0
</pre>

Revision as of 12:38, 6 March 2018

File: BSeq.STX, linked to library STX.LIB
See also: Sequences

The class BSeq can create and play sequences and provides an interface to the Programmer_Guide/Shell_Items/Wave/SET_WAVE#sequence wave-item functions.

Create an Instance of BSeq

Usage
bseq [ attr=value ; ... ]
cobj new bseq [ attr=value ; ... ]
attr=value, ...
initial values for sequence attributes (see member function Set)
Result
An instance of BSeq or an empty string
Description
Create and initialize a sequence instance and assign sequence attributes. To assign the attribute(s) the member function Set is called. In the descriptions of the member functions the first argument bseq_instance is an instance of the class BSeq created by this function.

Set Attributes

Usage
bseq_instance set attr=val [ ; ... ]
attr=val
Assign the value val to the attribute attr (see description below)
Result
always 0
Description
Assign sequence attributes. An attribute value is assigned only if it is valid. For some attributes automatic corrections are applied. Multiple attribute assignments separated by semi-colons can be specified. Attribute names and value keywords can be abbreviated.
Supported attributes
  • channel=n → set the number of channels (1 ≤ n ≤ 256)
  • envelope=type,ton,toff → set global envelope type (none, linear or cosine) and the on/off time (in ms, ≥ 0).
  • factor=a → set global amplitude factor (a ≠ 0)
  • srate=frq → set sampling rate in Hz (> 0).

Get Attribute

Usage
bseq_instance get attr
attr
name of the attribute to retrieve (see description below)
Result
value of specified attribute or an empty string
Description
Retrieve a sequence attribute.
Supported attributes
  • channel → get number of channels
  • envelope → get global envelope definition (type,ton,toff)
  • factor → get global amplitude factor
  • srate → get sampling rate
  • signals → get number of signal definitions
  • table → get signal definition table

Define Sequence Signals

Add Signal

Usage
bseq_instance signal ch ; base ; time ; sigtype ; sigpars
ch
sequence channel number (1, 2, ..), 0 or * for all channels
base
defines the base (origin) for the signal begin time; possible values are absolut, begin and end
time
the offset time to the selected base (origin) in seconds
sigtype ; sigpars
set the type and parameters of the new signal (see below)
Result
0 for success and a non-zero value if failed
Description
Define a new sequence signal and add it to the sequence definition. If ch is set to 0 or * the new signal is added to each sequence channel, otherwise it is added only to the specified channel. The timebase base selects how the time value time is used. If it is set to absolute, time is an absolute time (0 = begin of the signal). If base is set to begin or end, time is an offset to the beginning or end of the previous signal. The signal itself is defined by sigtype and sigpars.
sigtype sigpars signal
pause d A zero signal (pause) with a duration of d seconds.
value d ; v A constant signal (dc) with a duration of d seconds and an amplitude v.
noise d ; a A linear distributed noise with a duration of d seconds and an amplitude a.
rectangle d ; a ; f ; q A rectangle function with a duration of d seconds, an amplitude a, a frequency f Hz and a duty cycle q (0 < q < 1).
rectangle d ; a ; f ; q A triangle function with a duration of d seconds, an amplitude a, a frequency f Hz and a duty cycle q (0 < q < 1).
tone d ; a ; f ; p ; n ; da ; df A sine wave or a harmonic tone with a duration of d seconds, an amplitude a, a frequency f Hz and a phase p rad. If the number of harmonics n is greater than one, the values da (def.=1) and df (def.=f) are used to compute the amplitude and frequency of component i (= 1..n):
ai = a . dai-1; fi = df + f . (i-1)
segment aset ; aseg ; ach ; a Adds the signal of segment aseg and channel ach of audio set aset to the sequence. If ach is set to 0 or * all channels are added to the sequence (1 -> ch, 2 -> ch+1, ...). The value a is used as amplification factor.
Notes
  • Gaps are filled with zero (pause). This means, all regions of a sequence, where no signal is assigned are implicit set to pause.
  • Signals which are overlapping in time are mixed (added).
  • The member functions envelope, filter, fmod and amod can be used to apply special processing to a defined signal.

Delete Signal

Usage
bseq_instance delete pos

.;pos: the index of the signal; * for the last defined signal

Result
always 0
Description
Delete the specified signal defintion from the sequence.

Assign Envelope

Usage
bseq_instance envelope pos ; type ; t1 a1 t2 a2 ...
pos
the signal index; * for last defined signal
type
the type of envelope. The types none (no envelope), linear and cosine are supported
tX aX
the envelope points; each point is defined by a time tX (in seconds) and an amplitude factor aX.
Result
0 for success and a non-zero value if failed
Description
Define an envelope function for the signal pos. An envelope is defined by the function type and a set of points, each one defined with a time and an amplitude value (tX and aX). The time values can be specified as an offset from the beginning (tX > 0) or from the end (tX &lt 0). If no point at the begin/end of the signal is defined a begin/end point with amplitude 0 is automatically added (→ the signal starts/ends with zero amplitude).
If the argument type is set to none the envelope function for the signal pos is cleared.

Assign Filter

Usage
bseq_instance filter pos ; type ; f1 ; f2 ; inv ; order ; damp ; ripple
pos
the signal index; * for last defined signal
type
the type of filter. The filter types none (no filter), elliptic, butterworth and chebychev are supported
f1, f2: the frequency band in Hz
inv
if set to yes (or 1) the frequency response is inverted, otherwise (no or 0) not.
order
the filter order; this must be must an integer greater than 1 (default=5)
damp
the stopband damping in dB; damp ≥ 10 (default=60)
ripple
the passband ripple in dB; 0 < ripple ≤ 10 (default=1)
Result
0 for success and a non-zero value if failed
Description
Define a filter for the signal pos. The filter applied to the signal is an IIR filter of the specified type. The arguments f1, f2 and inv define the passband/stopband of the filter (see below). The parameters order, damp and ripple define the damping, the passband linearity and the slopes.).
If the argument type is set to none the filter for the signal pos is cleared.

Filter types (with: fmax = half sampling rate):

  • f1 = 0, f2 > 0, inv = 0 → lowpass
  • f1 > 0, f2 = fmax, inv = 0 → highpass
  • 0 < f1 < f2 < fmax, inv = 0 → bandpass
  • 0 < f1 < f2 < fmax, inv = 1 → bandstop (notch)

Assign Frq-Modulation

Usage
bseq_instance fmod pos ; none
bseq_instance fmod pos ; sine ; rate ; bw ; p
bseq_instance fmod pos ; rectangle|triangle ; rate ; bw ; dc
bseq_instance fmod pos ; sweep ; w ; k
rate, bw
modulation rate and bandwidth in Hz
p: starting phase of sine modulation in rad (default=0)
dc: duty cycle factor rectangle and triangle modulation (0 < dc < 1, default=0.5)
w, k: width (w, in Hz) and exponent (k, ≥ 0) for sweep function
Result
0 for success and a non-zero value if failed
Description
Define a frequency modulation or a sweep function for the signal pos. Modulating frequency makes only sense for periodic signal generators (e.g. rectangle, triangle or tone).
If the keyword none is used, the frq-modulation for the signal pos is cleared.
Computation of frequency modulation:
f(t) = f + bw/2 . m(t)
  • f: the frequency assigned to the signal generator (carrier)
  • bw</: the modulation bandwidth in Hz (> 0)
  • m(t): the modulation function (depends on selected function type, rate and p|dc)
  • f(t): modulated frequency at time t
Computation of sweep function:
linear sweep if k = 0: f(t) = f + w . t / d
exponential sweep if k > 0: f(t) = f + w . (t / d)k
  • f: the frequency assigned to the signal generator (carrier)
  • d: the duration assigned to the signal generator
  • w</: the sweep width (in Hz, ≠ 0)
  • k</: the sweep exponent (≥ 0)
  • f(t): sweep frequency at time t

Assign Amp-Modulation

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