// returns 0 if successful
int openPCMfromDeviceID(int deviceID, snd_pcm_t** handle, int isSource, int hardware) {
char buffer[200];
int ret;
initAlsaSupport();
getDeviceStringFromDeviceID(buffer, deviceID, !hardware, ALSA_PCM);
TRACE1("Opening ALSA device %s\n", buffer);
ret = snd_pcm_open(handle, buffer,
isSource?SND_PCM_STREAM_PLAYBACK:SND_PCM_STREAM_CAPTURE,
SND_PCM_NONBLOCK);
if (ret != 0) {
ERROR1("snd_pcm_open returned error code %d \n", ret);
*handle = NULL;
}
return ret;
}
/*
userData is assumed to be a pointer to ALSA_MIDIDeviceDescription.
ALSA_MIDIDeviceDescription->index has to be set to the index of the device
we want to get information of before this method is called the first time via
iterateRawmidiDevices(). On each call of this method,
ALSA_MIDIDeviceDescription->index is decremented. If it is equal to zero,
we have reached the desired device, so action is taken.
So after successful completion of iterateRawmidiDevices(),
ALSA_MIDIDeviceDescription->index is zero. If it isn't, this is an
indication of an error.
*/
static int deviceInfoIterator(UINT32 deviceID, snd_rawmidi_info_t *rawmidi_info,
snd_ctl_card_info_t *cardinfo, void *userData) {
char buffer[300];
ALSA_MIDIDeviceDescription* desc = (ALSA_MIDIDeviceDescription*)userData;
#ifdef ALSA_MIDI_USE_PLUGHW
int usePlugHw = 1;
#else
int usePlugHw = 0;
#endif
TRACE0("deviceInfoIterator\n");
initAlsaSupport();
if (desc->index == 0) {
// we found the device with correct index
desc->deviceID = deviceID;
buffer[0]=' '; buffer[1]='[';
// buffer[300] is enough to store the actual device string w/o overrun
getDeviceStringFromDeviceID(&buffer[2], deviceID, usePlugHw, ALSA_RAWMIDI);
strncat(buffer, "]", sizeof(buffer) - strlen(buffer) - 1);
strncpy(desc->name,
(cardinfo != NULL)
? snd_ctl_card_info_get_id(cardinfo)
: snd_rawmidi_info_get_id(rawmidi_info),
desc->strLen - strlen(buffer));
strncat(desc->name, buffer, desc->strLen - strlen(desc->name));
desc->description[0] = 0;
if (cardinfo != NULL) {
strncpy(desc->description, snd_ctl_card_info_get_name(cardinfo),
desc->strLen);
strncat(desc->description, ", ",
desc->strLen - strlen(desc->description));
}
strncat(desc->description, snd_rawmidi_info_get_id(rawmidi_info),
desc->strLen - strlen(desc->description));
strncat(desc->description, ", ", desc->strLen - strlen(desc->description));
strncat(desc->description, snd_rawmidi_info_get_name(rawmidi_info),
desc->strLen - strlen(desc->description));
TRACE2("Returning %s, %s\n", desc->name, desc->description);
return FALSE; // do not continue iteration
}
desc->index--;
return TRUE;
}
int deviceInfoIterator(UINT32 deviceID, snd_pcm_info_t* pcminfo,
snd_ctl_card_info_t* cardinfo, void* userData) {
char buffer[300];
ALSA_AudioDeviceDescription* desc = (ALSA_AudioDeviceDescription*)userData;
#ifdef ALSA_PCM_USE_PLUGHW
int usePlugHw = 1;
#else
int usePlugHw = 0;
#endif
initAlsaSupport();
if (desc->index == 0) {
// we found the device with correct index
*(desc->maxSimultaneousLines) = needEnumerateSubdevices(ALSA_PCM) ?
1 : snd_pcm_info_get_subdevices_count(pcminfo);
*desc->deviceID = deviceID;
buffer[0]=' '; buffer[1]='[';
// buffer[300] is enough to store the actual device string w/o overrun
getDeviceStringFromDeviceID(&buffer[2], deviceID, usePlugHw, ALSA_PCM);
strncat(buffer, "]", sizeof(buffer) - strlen(buffer) - 1);
strncpy(desc->name,
(cardinfo != NULL)
? snd_ctl_card_info_get_id(cardinfo)
: snd_pcm_info_get_id(pcminfo),
desc->strLen - strlen(buffer));
strncat(desc->name, buffer, desc->strLen - strlen(desc->name));
strncpy(desc->vendor, "ALSA (http://www.alsa-project.org)", desc->strLen);
strncpy(desc->description,
(cardinfo != NULL)
? snd_ctl_card_info_get_name(cardinfo)
: snd_pcm_info_get_name(pcminfo),
desc->strLen);
strncat(desc->description, ", ", desc->strLen - strlen(desc->description));
strncat(desc->description, snd_pcm_info_get_id(pcminfo), desc->strLen - strlen(desc->description));
strncat(desc->description, ", ", desc->strLen - strlen(desc->description));
strncat(desc->description, snd_pcm_info_get_name(pcminfo), desc->strLen - strlen(desc->description));
getALSAVersion(desc->version, desc->strLen);
TRACE4("Returning %s, %s, %s, %s\n", desc->name, desc->vendor, desc->description, desc->version);
return FALSE; // do not continue iteration
}
desc->index--;
return TRUE;
}
/*
direction has to be either SND_RAWMIDI_STREAM_INPUT or
SND_RAWMIDI_STREAM_OUTPUT.
Returns 0 on success. Otherwise, MIDI_OUT_OF_MEMORY, MIDI_INVALID_ARGUMENT
or a negative ALSA error code is returned.
*/
INT32 openMidiDevice(snd_rawmidi_stream_t direction, INT32 deviceIndex,
MidiDeviceHandle** handle) {
snd_rawmidi_t* native_handle;
snd_midi_event_t* event_parser = NULL;
int err;
UINT32 deviceID;
char devicename[100];
#ifdef ALSA_MIDI_USE_PLUGHW
int usePlugHw = 1;
#else
int usePlugHw = 0;
#endif
TRACE0("> openMidiDevice()\n");
(*handle) = (MidiDeviceHandle*) calloc(sizeof(MidiDeviceHandle), 1);
if (!(*handle)) {
ERROR0("ERROR: openDevice: out of memory\n");
return MIDI_OUT_OF_MEMORY;
}
// TODO: iterate to get dev ID from index
err = getMidiDeviceID(direction, deviceIndex, &deviceID);
TRACE1(" openMidiDevice(): deviceID: %d\n", (int) deviceID);
getDeviceStringFromDeviceID(devicename, deviceID,
usePlugHw, ALSA_RAWMIDI);
TRACE1(" openMidiDevice(): deviceString: %s\n", devicename);
// finally open the device
if (direction == SND_RAWMIDI_STREAM_INPUT) {
err = snd_rawmidi_open(&native_handle, NULL, devicename,
SND_RAWMIDI_NONBLOCK);
} else if (direction == SND_RAWMIDI_STREAM_OUTPUT) {
err = snd_rawmidi_open(NULL, &native_handle, devicename,
SND_RAWMIDI_NONBLOCK);
} else {
ERROR0(" ERROR: openMidiDevice(): direction is neither SND_RAWMIDI_STREAM_INPUT nor SND_RAWMIDI_STREAM_OUTPUT\n");
err = MIDI_INVALID_ARGUMENT;
}
if (err < 0) {
ERROR1("< ERROR: openMidiDevice(): snd_rawmidi_open() returned %d\n", err);
free(*handle);
(*handle) = NULL;
return err;
}
/* We opened with non-blocking behaviour to not get hung if the device
is used by a different process. Writing, however, should
be blocking. So we change it here. */
if (direction == SND_RAWMIDI_STREAM_OUTPUT) {
err = snd_rawmidi_nonblock(native_handle, 0);
if (err < 0) {
ERROR1(" ERROR: openMidiDevice(): snd_rawmidi_nonblock() returned %d\n", err);
snd_rawmidi_close(native_handle);
free(*handle);
(*handle) = NULL;
return err;
}
}
if (direction == SND_RAWMIDI_STREAM_INPUT) {
err = snd_midi_event_new(EVENT_PARSER_BUFSIZE, &event_parser);
if (err < 0) {
ERROR1(" ERROR: openMidiDevice(): snd_midi_event_new() returned %d\n", err);
snd_rawmidi_close(native_handle);
free(*handle);
(*handle) = NULL;
return err;
}
}
(*handle)->deviceHandle = (void*) native_handle;
(*handle)->startTime = getTimeInMicroseconds();
(*handle)->platformData = event_parser;
TRACE0("< openMidiDevice(): succeeded\n");
return err;
}
