Fluid MIDI

Requirements

• Fluid MIDI currently only supports 64-bit Windows and Mac OS for both editor and player
• SoundFont and MIDI files can only be loaded as streaming assets

Quick Start

1. Import SoundFont and MIDI files

Add all your SoundFont and MIDI files to the StreamingAssets folder. See the Unity documentation on streaming assets for more information.

2. Select host GameObjects

MIDI player components must be hosted in GameObjects. Create new ones or select existing ones. One possible setup could be to have one GameObject for the synthesizer and another GameObject for the songs. You can also just have them all in the same GameObject.

3. Create Synthesizer

The Synthesizer component loads a SoundFont, which is used by songs. Add a Synthesizer to your GameObject.

If a SoundFont is detected in your streaming assets, the Synthesizer will automatically be configured to use it. Otherwise, select the SoundFont you want to use.

4. Create SongPlayer

The SongPlayer component controls MIDI file loading and playback. Add a SongPlayer to your GameObject.

If a Synthesizer component is detected, the SongPlayer will be automatically configured to use it. Otherwise, select a Synthesizer for your SongPlayer. Next, select a song. This must be a MIDI file located in your streaming assets. If you want the song to start playing when the SongPlayer is started, select “Play On Start”.

5. Configure Audio Mixer

Song audio is output through an Audio Mixer effect. If you do not have an Audio Mixer, you can add one using the “Assets” menu by selecting “Create > Audio Mixer”

Next, select the Audio Mixer and uncheck “Auto Mixer Suspend” in the inspector.

Next, open the “Audio Mixer” panel, select the mixer, click the “Add” button, and select the “FluidSynth” effect.

6. Configure AudioSource

An AudioSource must be configured to “prime” the Audio Mixer. Add an AudioSource to any GameObject and ensure that it is set to “Play On Awake” and outputs to the Audio Mixer that contains the “FluidSynth” effect.

7. Play the Scene

If everything is configured correctly, you should now hear music playing when you start the scene. If you do not hear anything, view the console to see if any errors have been logged.

Reference

Synthesizer

A Synthesizer does not play any music on its own. It simply hosts a SoundFont, which can be used by a SongPlayer. When a Synthesizer is enabled, it will load the SoundFont, so it will be immediately ready for use. Otherwise, the SoundFont will be loaded on demand for each SongPlayer.

Inspector

• Sound Font - The SoundFont file to use for this Synthesizer. Must be a streaming asset.

Scripting

Synthesizer extends MonoBehaviour.

SongPlayer

A SongPlayer is the main component that controls song loading and playback. You should have a different SongPlayer for each song. When a SongPlayer is enabled, it will load the song, so it is ready to play. When a SongPlayer is disabled, no song is loaded, so there may be a delay before playback can start.

Inspector

• Synthesizer - Reference to a Synthesizer in the scene. The SongPlayer will use the SoundFont from this Synthesizer.
• Song - MIDI file for this SongPlayer. Must be a streaming asset.
• Play On Start - Play the song when the SongPlayer is started
• Unload On Stop - Disable this SongPlayer when the song finishes playing or is stopped. This effectively unloads the song from memory.
  • Delay - Seconds to wait before unloading the song. This can be useful to let some notes finish playing.
• Loop - Start playing the song again when it reaches the end
  • Start Ticks - The time at which to start playing again
• End Ticks - Specify a different end time. Consider the song complete when it reaches these ticks.
• Gain - Adjust the volume of the song
• Tempo - Adjust the song tempo by the specified multiplier
• Channels - Enabled MIDI channels for the song. Instruments on each channel will depend on the song, but channel 10 is reserved for percussion. Disabled channels will not produce sound.

Scripting

SongPlayer extends MonoBehaviour.

Property	Description
int Ticks	Current playback ticks. Useful for synchronizing game events to music.
float Gain	Get or set the song gain. Shound be a value between 0 and 100, with 0.2 as the default.
float Tempo	Get or set the song tempo multiplier. Should be value between 0.001 and 1000, with 1 as the default.
bool IsReady	True if the song has been loaded and playback can begin with minimal latency.
bool IsPlaying	True if the song is playing. A paused song is still considered to be playing.
bool IsPaused	True if the song is paused. A paused song is still considered to be playing.
bool IsDone	True if the song is finished playing, either becaue it was stopped or reached the end.

Method	Description
static void PauseAll()	Pauses all playing songs.
static void ResumeAll()	Resumes all paused songs.
static void StopAll()	Stops all playing songs.
void Play()	Plays the song. If the SongPlayer is not enabled, this method will enable it and load the song. Playback always begins from the start of the song.
void Stop()	Stops the song. If it was paused, it can no longer be resumed.
void Pause()	Pauses the song if it is playing.
void Resume()	Resumes the song if it is paused.
bool Seek(int ticks)	Moves the platyback position to the specified ticks. The song must be playing for this to work. Returns true if successful. A seek may fail if it is requested before a previous seek has completed.
bool IsChannelEnabled(int channel)	Returns true if the specified MIDI channel is enabled. Channel should be between 1 and 16, inclusive.
void EnableChannels(params int[] channels)	Enables the specified MIDI channels. Channels should be between 1 and 16, inclusive.
void DisableChannels(params int[] channels)	Disables the specified MIDI channels. Disabled channels do not produce sounds. Channels should be between 1 and 16, inclusive.

Troubleshooting

I can’t select a SoundFont in the Synthesizer or a MIDI file in the SongPlayer

• Make sure your SoundFont and MIDI files are located in the StreamingAssets folder. See the Unity documentation for more information on streaming assets.
• SoundFont and MIDI files are checked for validity before adding, so ensure the files are not corrupt

I don’t hear any music when I play my scene

• If you expect playback to happen without any scripting, ensure “Play On Start” is selected on the SongPlayer
• Make sure you have an Audio Mixer configured with the ‘FluidSynth’ effect added
• Make sure “Auto Mixer Suspend” is not checked on your Audio Mixer
• Ensure that the GameObject hosting the SongPlayer is active

I hear music in the editor but not in the player

• Ensure that you have an AudioSource configured with “Play on Awake” and output set to the Audio Mixer that has the “FluidSynth” effect

Song does not play after pausing

• You must call Resume() to resume playing a paused song.

Support

Please send questions or comments to support@thunkmonkey.com