Host Events Specification

Table of contents

  1. Specification of the Information Required from the Host
  2. Specification of the Information Required from the Host
    1. Available Events
    2. Modifying event_communication_settings int settings.json

For this Stage of Deployment, You should modify the following file

settings.json

Specification of the Information Required from the Host

Prior to running the inference on a given model, all or some of the hosts play-head information, incoming MIDI messages, and possibly parameters controlled via a graphical interface must be reformatted according to a given models input requirements. ITP thread is responsible for this task.

In this thread, all necessary information is sequentially provided to carry out the tokenization (or representation) of the relevant symbolic information into a tensor-like format.

Specification of the Information Required from the Host

Depending on the task at hand, the type of information as well as the frequency at which they are required may vary. For instance, in the case of a model that only requires the onset of notes with their corresponding time-stamp, the ITP thread will only require the Note On MIDI Messages. On the other hand, for a model that requires the full MIDI messages as well as bar/beat, meter information, the ITP thread will require to receive extra information from the host (namely, the MIDI messages and the bar/beat information). NeuralMidiFx allows you to easily specify the subset of the information you need from the host.

Edit the event_communication_settings in the settings.json file to specify the information required from the host.

Available Events

In this context, an event is a piece of information that is sent to the ITP thread notifying it of a change in the host`s state or a new incoming MIDI message.

The available events are:

  • FirstBufferEvent –> The very first event sent by the host when the playhead starts. This event is useful to figure out when the host starts playing.
  • PlaybackStoppedEvent –> The event sent by the host as soon as the playhead stops. This event is useful to figure out when the host stops playing.
  • NewBufferEvent –> The event sent by the host at the beginning of every new buffer (if playhead is running). In case you have a specific model that requires to know the position of the playhead at any given time, use this event. (See Plugin Basics chapter if you are not familiar with the concept of buffer)
  • NewBarEvent –> The event sent by the host at the beginning of every new bar (if playhead is running). In case you use bar locations in your tokenization process, use this event.
  • NewTimeShiftEvent –> The event sent by the host every N quarter notes (if playhead is running). In case you use specific locations (such as every beat, every 16th note, etc.) in your tokenization process, use this event.
  • NoteOnEvent –> The event sent by the host when a note is played.
  • NoteOffEvent –> The event sent by the host when a note is released.
  • CCEvent –> The event sent by the host when a CC message is received.

Modifying event_communication_settings int settings.json

To modify the

Setting NameDescription
SendEventAtBeginningOfNewBuffers_FLAGSend the metadata over to ITP whenever a new buffer arrives
SendEventForNewBufferIfMetadataChanged_FLAGOnly send if the buffer status changes (i.e. tempo changes, meter changes. …)
SendNewBarEvents_FLAGNotify the beginning of a new bar.
SendTimeShiftEvents_FLAGEvent from host at specific ratios of quarter notes (specified by delta_TimeShiftEventRatioOfQuarterNote)
FilterNoteOnEvents_FLAGFilter Note On Events if not needed.
FilterNoteOffEvents_FLAGFilter Note Off Events if not needed.
FilterCCEvents_FLAGFilter CC Events if not needed.