MIDI Channels and Controls

Work with per-channel state such as instrument, volume, and pitch behavior. More...

Properties
MPTKChannels	MidiPlayerTK.MidiStreamPlayer.MPTK_Channels [get]
	Description and list of MIDI channels associated with the synth. Each MIDI synth has 16 channels that carry all the relevant MIDI information.

Detailed Description

Work with per-channel state such as instrument, volume, and pitch behavior.

This chapter focuses on channel-level control during live playback.

Channel API

• MPTK_Channels
• MPTKChannels
• MPTKChannel

Related concept

• MPTKChannels and MPTKChannel Concepts

Properties

MPTK_Channels

MPTKChannels MidiPlayerTK.MidiStreamPlayer.MPTK_Channels

get

Description and list of MIDI channels associated with the synth. Each MIDI synth has 16 channels that carry all the relevant MIDI information.

• Current instrument / bank
• Volume
• Mute / Unmute (see Enable)
• Pitch bend ...

Channels distinguish instruments and provide independent control for each one. By sending MIDI messages on each channel, you can change instrument, volume, pitch, and other parameters. In Maestro MPTK, channels are indexed from 0 to 15. Channel 9 is reserved for drum sounds.

 
 
 
            HelperDemo.GUI_Horizontal(HelperDemo.Zone.BEGIN);
            GUILayout.Label("Channel   Preset Name                                   Preset / Bank",
                myStyle.TitleLabel3, GUILayout.Width(60 + 140 + 120 + 100 + 110));
            GUILayout.Label(" Count    Enabled       Volume",
                myStyle.TitleLabel3, GUILayout.Width(900));
            HelperDemo.GUI_Horizontal(HelperDemo.Zone.END);
 
            // Also available for MidiStreamPlayer, MidiInReader, MidiExternalPlayer.
            for (int channel = 0; channel < midiFilePlayer.MPTK_Channels.Length; channel++)
            {
                HelperDemo.GUI_Horizontal(HelperDemo.Zone.BEGIN);
 
                // Display channel number and log info
                if (GUILayout.Button($"   {channel:00}", myStyle.TitleLabel3, GUILayout.Width(60)))
                    Debug.Log(midiFilePlayer.MPTK_Channels[channel].ToString());

 
                // Display preset name
                GUILayout.Label(midiFilePlayer.MPTK_Channels[channel].PresetName ?? "not set", myStyle.TitleLabel3, GUILayout.Width(140));
 
                // Display preset and bank index
                int presetNum = midiFilePlayer.MPTK_Channels[channel].PresetNum;
                int bankNum = midiFilePlayer.MPTK_Channels[channel].BankNum;
                int presetForced = midiFilePlayer.MPTK_Channels[channel].ForcedPreset;
 
                // Check if preset is forced and build a string info
                string sPreset = presetForced == -1 ? $"{presetNum} / {bankNum}" : $"F{presetForced} / {bankNum}";
 
                // Slider to change the preset on this channel from -1 (disable forced) to 127.
                int forcePreset = (int)HelperDemo.GUI_Slider(sPreset, presetNum, -1f, 127f, alignCaptionRight: true, widthCaption: 120, widthSlider: 100, widthLabelValue: -1);
 
                if (forcePreset != presetNum)
                {
                    // Force a preset and a bank whatever the MIDI events from the MIDI file.
                    // set forcePreset to -1 to restore to the last preset and bank value known from the MIDI file.
                    // let forcebank to -1 to not force the bank.
                    // Before v2.10.1 midiFilePlayer.MPTK_ChannelForcedPresetSet(channel, forcePreset, forceBank);
                    midiFilePlayer.MPTK_Channels[channel].ForcedBank = forceBank;
                    midiFilePlayer.MPTK_Channels[channel].ForcedPreset = forcePreset;
 
                }
 
                // Display count note by channel
                GUILayout.Label($"{midiFilePlayer.MPTK_Channels[channel].NoteCount,-5}", myStyle.LabelRight, GUILayout.Width(100));

 
                // Toggle to enable or disable a channel
                GUILayout.Label("   ", myStyle.TitleLabel3, GUILayout.Width(20));
                bool state = GUILayout.Toggle(midiFilePlayer.MPTK_Channels[channel].Enable, "", GUILayout.MaxWidth(20));
                if (state != midiFilePlayer.MPTK_Channels[channel].Enable)
                {
                    midiFilePlayer.MPTK_Channels[channel].Enable = state;
                    Debug.LogFormat("Channel {0} state:{1}, preset:{2}", channel, state, midiFilePlayer.MPTK_Channels[channel].PresetName ?? "not set"); /*2.84*/
                }

 
                // Slider to change volume
                float currentVolume = midiFilePlayer.MPTK_Channels[channel].Volume;
                float volume = HelperDemo.GUI_Slider(null, currentVolume, 0f, 1f, alignCaptionRight: true, enableButton: false, widthCaption: -1, widthSlider: 100, widthLabelValue: 40);
                if (volume != currentVolume)
                    midiFilePlayer.MPTK_Channels[channel].Volume = volume;

 
                HelperDemo.GUI_Horizontal(HelperDemo.Zone.END);
            }