Getting (Linux) ALSA midi support to work with Hatari
=====================================================

If you don't have a real MIDI sequencer, use a software synthetizer.
For links to software referenced in this text, see end of the text.
Most of the distros should have in their repositories packages at
least for some of them though.

There are also some notes about midi networking.


Making MIDI soft-synthetizer to work with ALSA
-----------------------------------------------

Make Timidity into an ALSA output device with:
  timidity -Os -iA
(-O: output=alsa, -i: interface=alsa)

To make it use less CPU and be more responsive, use:
  timidity -Os -iA -B2,8 -EFreverb=0 -EFchorus=0
(-B: 2,8=set small buffers, -EFx=0: disable effects)

Make vkeybd (virtual midi keyboard app) into an ALSA input device with:
  vkeybd

View the resulting (software) ALSA input and output devices:
  aconnect -i -o

Then connect the vkeybd input to timidity output with:
  kaconnect
or if you don't have this UI program, just use 'aconnect' directly:
  aconnect <sender port> <receiver port>

Now you can use the virtual midi keyboard for testing the sound
synthesis.


Finally You can test how well midi files are played.
Check which ALSA port Timidity provides:
  aplaymidi -l

And use that port for playing a midi file:
  aplaymidi -p <port, e.g. 129:0> test.mid
(or use 'pmidi')

Note: Remember that you need to re-connect the (virtual) device
ports each time you restart them.


Using FluidSynth instead of Timidity
------------------------------------

Instead of Timidity, you also use other soft-synthetizers,
like FluidSynth:
  fluidsynth --audio-driver=alsa --midi-driver=alsa_seq soundfont.sf2

You could play a bit with other options to get more performance,
sound volume etc:
  --reverb=no --chorus=no -o synth.polyphony=16 --gain=0.6

And if you don't like the FluidSynth shell, use:
  --no-shell --server

FYI: Current (v1.0.7a) FluidSynth has buffer overruns, but they
will  be fixed in the next release (hopefully coming soon).


Making it all to work with Hatari
---------------------------------

Hatari requires midi hardware devices to work, it doesn't support
ALSA directly.  To get the software synth ALSA devices to appear
as HW midi devices, run following as *root*:
  modprobe snd-virmidi

When you you list your ALSA output devices with:
  aconnect -o
You should see in addition to Timidity also 4 virtual hardware
devices.

Then connect (either with aconnect or kaconnect) the first virtual
HW port to the same Timidity port where you connected the virtual
midi keyboard.

Now check which number your new virtual midi card got from ALSA:
  cat /proc/asound/cards

And give to Hatari the corresponding ALSA midi device.  In my case
VirMidi was Card 1 and as the port used above was first one, I give
Hatari the following midi device:
  hatari --midi /dev/snd/midiC1D0

Note: I also needed --nosound option because Hatari wanted exclusive
access to the PCM (sound) device and Timidity was already connected
to it.  This may not be the case if you've compiled Hatari with another
/ newer SDL_mixer library versions.


Sending the midi data over network
----------------------------------

If you direct the data to stdout, you can use e.g. ssh to pipe
it over network:
  hatari --midi /dev/stdout --log /dev/stderr |\
    ssh user@remote.site "cat>/dev/snd/midiC1D0"

Note that logging is re-directed to stderr so that it doesn't
mess the midi output.

Same can be done with socat so that the connections are bi-directional.
Once Hatari supports midi input, you can use socat like this to do
midi-networking between (emulated) Ataris:
  @remote.site:
    socat PIPE:redirect.pipe TCP4-LISTEN:www
    hatari --midi redirect.pipe --log stderr
  @local.site:
    socat PIPE:redirect.pipe TCP4:remote.site:www
    hatari --midi redirect.pipe --log stderr


Links
-----

Software:

Vkeybd:
  http://alsa.opensrc.org/Vkeybd

Patch (ALSA connecting) utilities:
  http://alsa.opensrc.org/AlsaMidiPatchbays    

FluidSynth:
  http://www.iiwu.org/fluidsynth/

Soundfonts:
  http://alsa.opensrc.org/SoundFontHandling

List of some soft-synthetizers:
  http://alsa.opensrc.org/SoftSynths

socat:
  http://www.dest-unreach.org/socat/

MidiMaze:
  http://en.wikipedia.org/wiki/MIDI_Maze


Overviews:

ALSA midi overview:
  http://alsa.opensrc.org/AlsaMidiOverview

Virtual midi hardware setup:
  http://www.tldp.org/HOWTO/MIDI-HOWTO-10.html

Timidity Howto:
  http://lau.linuxaudio.org/TiMidity-howto.html

Midi with ALSA (old):
  http://www.linuxfocus.org/English/September2002/article259.shtml

Midi on Linux:
  http://www.linuxjournal.com/article/7773