MIDI Input Element

Summary ¶

	MIDI Input
Info
Category:	Input Registration		AddIn:	Base Layer
Creator:	OkazoLab		Scope:	Parent event
Owns Snippets:	None		Usage:	Snippets

Properties ¶

Name	Description	Constraints	Type	On runtime change
Settings
MIDI Device	Defines a MIDI device that sends an input to this element	Design Time..	Int32
Buffer Size	Defines the size of the circular internal buffer that holds an MIDI input (notes and events) at runtime. When all MIDI input has to be recorded the value should be greater than the expected overall length of input in notes or events.	Design Time..	Int32
Triggering Mode	Defines whether the element is triggered by every MIDI event (including e.g. contoller buttons) or only by a new note	Design Time..	enMIDI..
Test MIDI Input	Brings a dialog window that monitors the input of the selected MIDI device for testing purpose	Design Time..	Boolean
Runtime Input
MIDI Notes	Returns a runtime array of all MIDI notes received since the onset of the parent event. The last array element corresponds to the newest note. The current length of the array can be obtained by the .Length field. The array resets with the each onset of the parent event	Status..	clMIDI..
Newest Note	Returns the newest note received from the MIDI device	Status..	clMIDI..
MIDI Events	Returns a runtime array of all received MIDI events since the onset of the parent event. The built-in type of array elements is clMIDIEvent (the array itself - clMIDIEvent[] ) The last element corresponds to the newest event. The array resets with the each onset of the parent event	Status..	clMIDI..
Newest MIDI Event	Returns the newest event received from the MIDI device	Status..	clMIDI..
Runtime Status
Triggering Time	Indicates the latest event time when the element was triggered (in ms elapsed since activation of the parent event)	Status..	clTime
Is Triggered	Indicates that the element has been triggered at least once since the onset of the parent event	Normal..	Boolean
Control
Is Enabled	If set to false the element is completely omitted when the experiment is run	Design Time..	Boolean
Title	Title of the element	Design Time..	String

¶

Description ¶

Demo video ¶

Examples ¶

Traditional note signs and corresponding element's note names and sound frequencies

Practical Use ¶

Technique 1: Logging all MIDI input over a period of time ¶

1. Add new MIDI input element into the event where you plan to record notes played by a participant
2. Select the input MIDI device via MIDI Device property. The device has to be connected to PC and turn on
3. Choose whether you want to record all low-level MIDI events or just MIDI notes
4. Add a proxy variable on the MIDI Notes property. After the parent event ends, the proxy variable will returns all played notes as an array of clMIDINote structs
5. Read the MIDI notes array and record it into Report or into a custom file, like in the following snippet:
   

    //
   
   for (int i=0;i<MIDINotes.Length;i++)
   
   {
   
   Report=Report+MIDINotes[i].Note+";"+MIDINotes[i].Octave+";"+MIDINotes[i].StartTime+";"+MIDINotes[i].Duration+"\n\r"; /// record the note info into Report
   
   }
   
   

   
   There is no need to clean up the array because the MIDI Notes property is automatically reset on the next onset on the parent event
   

Technique 2: Detecting a time of the first played note or pressed piano button ¶

1. Add new MIDI input element into the event where you plan to record a note played by a participant
2. Select the input MIDI device via MIDI Device property. The device has to be connected to PC and turn on
3. Choose whether you want to detect a note (after button release) or button press. In the latter case, change the Triggering Mode to "On MIDI event"
4. Add proxy variables on the Last Note or Last Event property Is Triggered property. You can use Is Triggered as the event end condition via conditional flow route.
5. Write a recording code to the Triggered snippet of the MIDI Input element. The code may look like this:
   

    // if you want to detect a note
   
   Report=Report+LastNote.Name+";"+LastNote.Octave+";"+LastNote.StartTime+";"+LastNote.Duration+"\n\r";
   
   

   
   or
   

    // if you want to detect an initial press of piano button
   
   if ((LastEvent.Name=="NoteOn")&&(LastEvent.Data2>0)) /// select only the 'button-down' events
   
   Report=Report+LastEvent.Name+";"+LastEvent.MIDIChannel+";"+LastEvent.Time+";"+LastNote.Data1+";"+LastNote.Data2+"\n\r";
   
   

   
   The code will be executed when an incoming note or piano button press is detected. Instruct participants to do not press several buttons simultaneously because, only the last one will be detected by the given technique.