Introducing Wave Items

STx wave items are used to play and record soundfiles as well as generate signals and sequences of signals.

Playing Sound files

In order to play a sound file in STx, you need to load it into STx using the LOAD SOUNDFILE command. Once loaded, you can attach it to a WAVE item and play it back.

A macro which plays back a sound file.

[macro wave_item_play_example]
    //
    // ask user to select a soundfile from disk
    //
    #sf := butil 'FileDialog open ; Select a soundfile'
    if '$#sf' == '' exit
    //
    // load the soundfile in STx
    //
    load soundfile '$#sf' /Read
    if '$rc' > 0 em $rc ; LOAD SOUNDFILE failed ($emsg)
    readvar csfh #srate #nch #nsamples #code #type #mode
    //
    // create a wave item addressing the soundfile
    //
    #wave := new wave * 1_$#nsamples
    if '$#wave[?]' != 'wave' em -1 ; wave creation failed ($emsg)
    //
    // play the contents of the soundfile
    //
    $#wave play
    //
    // use message box to prevent script from ending
    //
    um 'Do you want to exit?'
    //
    // clean up
    //
    delete $#wave
exit

An alternative method is to use the XWAVE class:

[macro xwave_play_example]
    //
    // ask user to select a soundfile from disk
    //
    #sf := butil 'FileDialog open ; Select a soundfile'
    if '$#sf' == '' exit
    //
    // create XWAVE instance
    //
    #xwave := xwave '$#sf'
    if '$#xwave[?]' != 'instance' then
        em -1 ; Failed to create the xwave item.
    end
    //
    // play soundfile
    //
    $#xwave play
    //
    // clean up
    //
    $#xwave destroy
exit

Recording Sound files

A macro which records a signal to file.

[macro wave_item_record_example]
    //
    // create file to record to
    //
    #sf := bsf newdialog 44100 ; 2 ; PCM16
    if '$#sf' == '' exit
    //
    // load the soundfile in STx
    //
    bsf open $#sf
    bsf select $#sf
    readvar csfh #srate #nch #nsamples #code #type #mode
    //
    // create a wave item to record to
    //
    #wave := new wave * 0_44100
    if '$#wave[?]' != 'wave' em -1 ; wave creation failed ($emsg)
    //
    // record 1 second
    //
    $#wave record 44100
    if '$rc' > 0 em $rc ; RECORD failed ($emsg)
    //
    // use message box to prevent script from ending
    // before the signal has been recorded
    //
    um 'Stop recording?'
    $#wave stop
    //
    // clean up
    //
    delete $#wave
    bsf close $#sf
    if '$result' != '0' em $result ; closing soundfile failed
exit

Sequences

A 'sequence' is a virtual soundfile dynamically created in memory from a sequence definition. The sequence definition specifies the order and type of signals to sequence.

Sequence wave items are created using the option /Q.

Defining a Sequence

A sequence is defined using the wave item command SIGNAL. Defined signals can then be filtered using the filter commands (see Filtering a Sequence). When signal definitions and filtering have been done, the sequence is finalized using the END command. The sequence can then be accessed like any other wave item.

Introducing Wave Items

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