Midi Driver

Android midi driver using Sonivox EAS library

I have added an event queue as per the comment by akdmia. I have only tested this with this app, not with an extended event stream. The app just has a couple of buttons that play a couple of piano notes when touched. I've added two more buttons that play and stop a midi file using the MediaPlayer to check that there is no interaction problem. Added a listener for sending initial midi messages when the midi driver has started. This project may be compiled as a library by changing the setting in project.properties to android.library=true. You will either need to delete the MainActivity.java file or be evil and compile it with the about setting set to false before compiling it as a library. The compiler is clever enough not to recompile the sources.

To use this driver you need to:

• Get and install the Android NDK toolkit.
• Get the documentation and include files from https://github.com/android/platform_external_sonivox.
• Get a copy of the libsonivox.so library from an Android device or an emulator (in system/lib) and put it with the other libraries in the platforms/android-14/arch-arm/usr/lib folder of the NDK.
• Add it to your ~/jni/Android.mk file along with any other libraries.

Or you can just copy the libmidi.so file from here, but it has

Java_org_billthefarmer_mididriver_MidiDriver

embedded in the native method names.

The windows NDK toolkit doesn't appear to use anything other than standard windows shell commands and it's own tools, so you don't need Cygwin, despite what the docs say.

Methods

void start()  Start the driver. Call from onResume().

void stop()  Stop the driver. Call from onPause();

void addOnMidiStartListener(OnMidiStartListener l);

void queueEvent(byte[]) Send a midi message

Native Methods

int init()  Return buffer size in shorts, or 0 on failure.

int[] config()  Return a four element array of ints with part of
the EAS onfig:

  config[0] = pLibConfig->maxVoices;
  config[1] = pLibConfig->numChannels;
  config[2] = pLibConfig->sampleRate;
  config[3] = pLibConfig->mixBufferSize;

int render(short buffer[]) Renders a buffer's worth of audio from
the Sonivox synthesizer into the buffer provided. The buffer
should be an array of shorts of the size returned by init(). Returns
0 on failure, number of shorts rendered on success.

boolean write(byte buffer[])  Writes midi data to the Sonivox
synthesizer. The length of the array should be the exact length of
the message or messages. Returns true on success, false on
failure.

boolean shutdown()  Shut down the synthesizer. Returns true on
success, false on failure.