Portmidi test program that works

miditest.c

#include "portmidi.h"
#include <iostream>

void writeDevice(PmDeviceID id) {
        std::cout << "Device #" << id << ":\n";
        const PmDeviceInfo* device = Pm_GetDeviceInfo(id);
        std::cout << "\tstructVersion: " << device->structVersion << "\n";
        std::cout << "\tinterf: " << device->interf << "\n";
        std::cout << "\tname: " << device->name << "\n";
        std::cout << "\tinput: " << device->input << "\n";
        std::cout << "\toutput: " << device->output << "\n";
        std::cout << "\topened: " << device->opened << "\n";
        std::cout << std::endl;
}

int main() {
        Pm_Initialize();
        int numDev = Pm_CountDevices();
        std::cout << "There are " << numDev << " devices" << std::endl;
        for (int i = 0; i < numDev; i++) {
                writeDevice(i);
        }
        std::cout << "Default in: " << Pm_GetDefaultInputDeviceID() << "\n";
        std::cout << "Default out: " << Pm_GetDefaultOutputDeviceID() << std::endl;
        Pm_Terminate();
        return 0;
}

Output on my pi:

There are 4 devices
Device #0:
        structVersion: 1994328172
        interf: ALSA
        name: Midi Through Port-0
        input: 0
        output: 1
        opened: 0

Device #1:
        structVersion: 0
        interf: ALSA
        name: Midi Through Port-0
        input: 1
        output: 0
        opened: 0

Device #2:
        structVersion: 0
        interf: ALSA
        name: TiMidity (BK) port 0
        input: 0
        output: 1
        opened: 0

Device #3:
        structVersion: 0
        interf: ALSA
        name: TiMidity (freepats) port 0
        input: 0
        output: 1
        opened: 0

Default in: 1
Default out: 0