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Some Music Libraries for Kotlin
with some .NET -> Kotlin migration stories
atsushieno
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Some Music Libraries for Kotlin
Dotnet Users Migration Path (DUMP) to Kotlin
atsushieno
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ktmidi
Versatile MIDI processing library
Provides access to MIDI 1.0 and/or UMP (MIDI 2.0) devices
Can create virtual devices (not doable in javax.sound.midi)
Supports MIDI 2.0 UMP (a handful of libraries do)
and MIDI-CI sessions (only JUCE in C++ and ktmidi in Kotlin do)
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MIDI? Is it still popular?
MIDI 2.0: 2020 2023 updates
- 7 bits => 32 bits
- 16 channels => 16 channels x 16 groups
- bidirectional like HTTP/3
Not for composition outputs, but it is used everywhere.
- MIDI keyboards
- within many cross-platform instrument plugins (implementation details)
- in many audio plugin APIs: AudioUnit, CLAP (MIDI2 since around 2022)
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Managed language for DAWs?
Yes, Java is used
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platform MIDI access: there are many backends
● ALSA
● WinMM
○ Windows MIDI Services in the future
● CoreMIDI
● rtmidi, libremidi, portmidi...
● Android MIDI API (android.media.midi)
● Web MIDI API
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surviving native interop hell (did I ...?)
managed-midi (~2018)
● P/Invoke (winmm, alsa, portmidi, rtmidi)
● Managed API
○ UWP
○ xamarin-macios
○ xamarin-android
simple-ish overall (no WebMIDI atm)
Someday we get some universal solution w/ cinterop...? 🥹
● Kotlin/JVM
○ LibreMidiAccess (LibreMidi) - panama
○ AlsaMidiAccess - javacpp
○ AndroidMidiAccess
○ JvmMidiAccess (javax.sound.midi)
● Kotlin/Native
○ CoreMidiAccess (cinterop)
○ RtMidiNativeAccess (cinterop)
● Kotlin/JS
○ JzzMidiAccess - Jazz-Soft/JZZ (npm)
● Kotlin/Wasm
○ WebMidiAccess - (webmidi)
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Text to Music files
I had a compiler tool for my own language (variant of Music Macro Language)
text => MIDI 2.0 song => DAW project file (using Tracktion_Engine OSS)
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Text to Music files
Text to MIDI
- antlr-kotlin to parse its syntax (in C# it was jay)
- generates standard MIDI file (SMF), or SMF2-alike
- embeddable to any Kotlin app
MIDI to some XML-based DAW project files
- ended up building my own .NET XML API ports
(XmlReader, XmlWriter, XLinq)
- XmlSerializer... no reflection in Kotlin, so codegen w/ KSP
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make it compile from VSCodium extension
The compiler package is up on npm using npm-publish
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compose-audio-controls
maybe
the coolest one
mine 🤣
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ImageStripKnob
Pick any image strip from 2400+ knobs from KnobGallery
(based on image strip)
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ImageStripKnob
Compact yet mobile-friendly
- sizes: align with Android UI Accessibility Guidelines
- drag to move your finger away horizontally without value changes
- adjust value vertically
- hold to switch to fine-tuning mode
No value
change Value change
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DiatonicKeyboard
Aligns with Android Accessibility Guideline
drag to naturally play next note, or pitch bend
horizontally or
vertically
(per-note)
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Demo, if time permits
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Repos
https://github.com/atsushieno/ktmidi/ - MIDI library
https://github.com/atsushieno/mugene-ng - text to MIDI compiler
https://github.com/atsushieno/augene-ng - ... to DAW XML project compiler
https://github.com/atsushieno/missing-dot - .NET XML API ports
https://github.com/atsushieno/compose-audio-controls/ - audio controls in KMP
https://github.com/atsushieno/kmdsp/ - visual MIDI player in KMP