void scan_cycle(alsa_rawmidi_t *midi)
{
int card = -1, err;
scan_t scan;
midi_port_t **ports;
//debug_log("scan: cleanup");
scan_cleanup(midi);
scan.midi = midi;
scan.iterator = &midi->scan.ports;
snd_rawmidi_info_alloca(&scan.info);
//debug_log("scan: rescan");
while ((err = snd_card_next(&card))>=0 && card>=0) {
char name[32];
snprintf(name, sizeof(name), "hw:%d", card);
if ((err = snd_ctl_open(&scan.ctl, name, SND_CTL_NONBLOCK))>=0) {
scan_card(&scan);
snd_ctl_close(scan.ctl);
} else
alsa_error("scan: snd_ctl_open", err);
}
// delayed open to workaround alsa<1.0.14 bug (can't open more than 1 subdevice if ctl is opened).
ports = &midi->scan.ports;
while (*ports) {
midi_port_t *port = *ports;
if (port->state == PORT_CREATED)
ports = scan_port_open(midi, ports);
else
ports = &port->next;
}
}
int is_output(snd_ctl_t *ctl, int card, int device, int sub) {
snd_rawmidi_info_t *info;
int status;
snd_rawmidi_info_alloca(&info);
snd_rawmidi_info_set_device(info, device);
snd_rawmidi_info_set_subdevice(info, sub);
snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_OUTPUT);
if ((status = snd_ctl_rawmidi_info(ctl, info)) < 0 && status != -ENXIO) {
return status;
} else if (status == 0) {
return 1;
}
return 0;
}
//list all the midi interfaces
void list_midi_interfaces(char* midi_dev, int bufsize)
{
register int err;
int cardNum;
char devices[5][14];
char user_midi[bufsize];
// Start with first card
cardNum = -1;
for (;;)
{
snd_ctl_t *cardHandle;
// Get next sound card's card number. When "cardNum" == -1, then ALSA
// fetches the first card
if ((err = snd_card_next(&cardNum)) < 0)
{
printf("Can't get the next card number: %s\n", snd_strerror(err));
break;
}
// No more cards? ALSA sets "cardNum" to -1 if so
if (cardNum < 0) break;
// Open this card's control interface. We specify only the card number -- not
// any device nor sub-device too
{
char str[64];
sprintf(str, "hw:%i", cardNum);
if ((err = snd_ctl_open(&cardHandle, str, 0)) < 0)
{
printf("Can't open card %i: %s\n", cardNum, snd_strerror(err));
continue;
}
}
{
int devNum;
// Start with the first MIDI device on this card
devNum = -1;
for (;;)
{
snd_rawmidi_info_t *rawMidiInfo;
register int subDevCount, i;
// Get the number of the next MIDI device on this card
if ((err = snd_ctl_rawmidi_next_device(cardHandle, &devNum)) < 0)
{
printf("Can't get next MIDI device number: %s\n", snd_strerror(err));
break;
}
// No more MIDI devices on this card? ALSA sets "devNum" to -1 if so.
// NOTE: It's possible that this sound card may have no MIDI devices on it
// at all, for example if it's only a digital audio card
if (devNum < 0) break;
// To get some info about the subdevices of this MIDI device (on the card), we need a
// snd_rawmidi_info_t, so let's allocate one on the stack
snd_rawmidi_info_alloca(&rawMidiInfo);
memset(rawMidiInfo, 0, snd_rawmidi_info_sizeof());
// Tell ALSA which device (number) we want info about
snd_rawmidi_info_set_device(rawMidiInfo, devNum);
// Get info on the MIDI outs of this device
snd_rawmidi_info_set_stream(rawMidiInfo, SND_RAWMIDI_STREAM_INPUT);
i = -1;
subDevCount = 1;
// More subdevices?
while (++i < subDevCount)
{
// Tell ALSA to fill in our snd_rawmidi_info_t with info on this subdevice
snd_rawmidi_info_set_subdevice(rawMidiInfo, i);
if ((err = snd_ctl_rawmidi_info(cardHandle, rawMidiInfo)) < 0)
{
printf("Can't get info for MIDI input subdevice hw:%i,%i,%i: %s\n", cardNum, devNum, i, snd_strerror(err));
continue;
}
// Print out how many subdevices (once only)
if (!i)
{
subDevCount = snd_rawmidi_info_get_subdevices_count(rawMidiInfo);
printf("\nFound %i MIDI input subdevices on card %i\n", subDevCount, cardNum);
}
// NOTE: If there's only one subdevice, then the subdevice number is immaterial,
// and can be omitted when you specify the hardware name
printf((subDevCount > 1 ? "[%i] - hw:%i,%i,%i\n" : "[%i] - hw:%i,%i\n"), i, cardNum, devNum, i);
sprintf(devices[i], (subDevCount > 1 ? "hw:%i,%i,%i\n":"hw:%i,%i\n"),cardNum, devNum, i);
}
}
}
// Close the card's control interface after we're done with it
snd_ctl_close(cardHandle);
}
snd_config_update_free_global();
printf("\nEnter the MIDI input to use (eg hw:1,0) > ");
scanf("%s",user_midi);
strncpy(midi_dev,user_midi,bufsize);
}
void list_subdevice_info(snd_ctl_t *ctl, int card, int device) {
snd_rawmidi_info_t *info;
const char *name;
const char *sub_name;
int subs, subs_in, subs_out;
int sub, in, out;
int status;
snd_rawmidi_info_alloca(&info);
snd_rawmidi_info_set_device(info, device);
snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_INPUT);
snd_ctl_rawmidi_info(ctl, info);
subs_in = snd_rawmidi_info_get_subdevices_count(info);
snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_OUTPUT);
snd_ctl_rawmidi_info(ctl, info);
subs_out = snd_rawmidi_info_get_subdevices_count(info);
subs = subs_in > subs_out ? subs_in : subs_out;
sub = 0;
in = out = 0;
if ((status = is_output(ctl, card, device, sub)) < 0) {
error("cannot get rawmidi information %d:%d: %s",
card, device, snd_strerror(status));
return;
} else if (status)
out = 1;
if (status == 0) {
if ((status = is_input(ctl, card, device, sub)) < 0) {
error("cannot get rawmidi information %d:%d: %s",
card, device, snd_strerror(status));
return;
}
} else if (status)
in = 1;
if (status == 0)
return;
name = snd_rawmidi_info_get_name(info);
sub_name = snd_rawmidi_info_get_subdevice_name(info);
if (sub_name[0] == '\0') {
if (subs == 1) {
printf("%c%c hw:%d,%d %s\n",
in ? 'I' : ' ',
out ? 'O' : ' ',
card, device, name);
} else
printf("%c%c hw:%d,%d %s (%d subdevices)\n",
in ? 'I' : ' ',
out ? 'O' : ' ',
card, device, name, subs);
} else {
sub = 0;
for (;;) {
printf("%c%c hw:%d,%d,%d %s\n",
in ? 'I' : ' ', out ? 'O' : ' ',
card, device, sub, sub_name);
if (++sub >= subs)
break;
in = is_input(ctl, card, device, sub);
out = is_output(ctl, card, device, sub);
snd_rawmidi_info_set_subdevice(info, sub);
if (out) {
snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_OUTPUT);
if ((status = snd_ctl_rawmidi_info(ctl, info)) < 0) {
error("cannot get rawmidi information %d:%d:%d: %s",
card, device, sub, snd_strerror(status));
break;
}
} else {
snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_INPUT);
if ((status = snd_ctl_rawmidi_info(ctl, info)) < 0) {
error("cannot get rawmidi information %d:%d:%d: %s",
card, device, sub, snd_strerror(status));
break;
}
}
sub_name = snd_rawmidi_info_get_subdevice_name(info);
}
}
}
