Multi port file support?

[BLumia]

Currently, TinyMidiLoader doesn't recognize MIDI port Meta Event, and TinySoundFont also don't have related support as well, which can cause incorrect playback in some MIDI file which uses such meta event.

Some example MIDI files that can be used to test:

• GK1.zip (will notice missing percussion)
• multi_port_collection.zip

Add parsing for that meta event in tml.h is (or might be) simple...

		switch (meta_type)
		{
			case TML_PORT:
				if (buflen != 1) { TML_WARN("Invalid length for Port meta event"); return -1; }
				evt->type = TML_PORT;
				evt->key = metadata[0]; // simply store it somewhere for later use..?
				break;
                        // ...

...but I can't find midi port-related support in tsf.h is that means this will be hard to implement in tsf?

Additional Context

I previously tested some other players to check if they support this meta event, the result:

• Timidity++: works fine
• QMidiPlayer (which is also based on fluidsynth): works fine
• Drumstick MIDI File Player (with fluidsynth selected): have the same issue
• vgmtrans (based on bassmidi, using built-in preview before extract the MIDI and SoundFont file): works fine
• XMPlay with MIDI plugin (based on bassmidi): works fine

There was a related discussion in FluidSynth as well, see FluidSynth/fluidsynth#1352 and FluidSynth/fluidsynth#1361.

[schellingb]

I think an implementation can do that perfectly fine on its own without TSF needing any additional support for it.
Like you said, TML would need the change you suggested to make it keep the events. Then the playback code can do whatever it needs to do to support it. TSF is not strictly tied to MIDI limitations, it can have as many channels as you want. So you could have your emulated port 0 be channels 0 to 15 and port 1 be channels 16 to 31 and so on. Just make sure the 10th channel always gets flag_mididrums set when calling tsf_channel_set_presetnumber.

[BLumia]

Sorry for the late reply. I agree! I submitted a PR to add TML_PORT to tml.h (#121). And I'll try implement related support in my own program :)