Dual Port midi file support

Hi! Late 90s midi sound modules like the Yamaha MU2000 and Roland SC-88 have two midi inputs for a total of 32 channels and higher bandwith both for complex songs and more accurate timing.

I'm not familiar with the MIDI file format but http://www.music.mcgill.ca/~ich/classes/mumt306/StandardMIDIfileformat.html seems to suggest the first 16 channels will be on track 1 of a midi file and the other 16 channels typically on track 2.

I have my SC-88 defined in audio midi setup as a two port device but QMidi will only let me chose port A or port B, not both at once.

This feature and a simply piano roll view are the only things I can think of that is missing from QMidi :)

http://miditrail.osdn.jp/MacOSX/MANUAL.en.html is a great alternative for visualising midi files and has the multi port support I'm talking about but it has no support at all for playlists, libraries or karaoke.

Hi!

Can you send me some sample 32channels MIDI files?
Thank you

There’s no such thing as a 32 channel SMF. By definition, each MIDI port can only send 16 channels. While it is possible to store multiple concurrent 16 channel tracks in a DAW (and route each to a separate MIDI port) you cannot save this as an SMF, only as the save format of the DAW. If you tried to, the DAW would ‘flatten’ the file down to 16 channels, mixing together the Ch1 information for both ports to one track.

MIDI 1.0 was invented before multi port interfaces, and no one thought that we would need a file format that supported more than 16 channels!

However, MIDI 2.0 is a totally new kettle of fish, but to my knowledge, no new SMF format has been standardized, and certainly no legacy modules will be able to understand it.

I think the only way QMIDI may be able to pull this off using MIDI 1.0 would be the ability to play two ‘normal’ SMF’s at the same time sent to two different ports.

Just noticing this a couple years later .

There definitely is such a thing as a 32 channel SMF! With type-1 SMF, this is done using track/port assignment meta events.
It is also possible to assign more than 32 channels, should the target device support it, such as the MU128 and later or SC-8820/50 devices. These utilize the serial to-host connection or USB to access the full range of internal ports. Some of the official demo midi files for Yamaha's MU devices use all 4 ports, but this is otherwise fairly rare, to my knowledge.

It seems like there have been multiple methods used to assign the ports, here is a little write-up on the topic:
http://midi.teragonaudio.com/tech/midifile/obsolete.htm
http://midi.teragonaudio.com/tech/midifile/port.htm

It would be very cool to have support for multi-port midi files in QMidi! Personally, I have quite a few of these, and have created some myself, but the options for playing them are pretty limited on a mac. Would be happy to share some example files if it would be helpful.

This web-based player supports 4-port playback:
https://shingo45endo.github.io/remiana/midi-file-player/

Yes it's possible (see https://sweet-midi-player.en.softonic.com/mac)
No, I'm not planning to add this feature at this time, but you can add you +1 to this forum thread 😊