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Diffstat (limited to '3rdparty/portmidi/pm_linux/pmlinuxalsa.c')
-rw-r--r--3rdparty/portmidi/pm_linux/pmlinuxalsa.c779
1 files changed, 779 insertions, 0 deletions
diff --git a/3rdparty/portmidi/pm_linux/pmlinuxalsa.c b/3rdparty/portmidi/pm_linux/pmlinuxalsa.c
new file mode 100644
index 00000000000..8e85cfe8650
--- /dev/null
+++ b/3rdparty/portmidi/pm_linux/pmlinuxalsa.c
@@ -0,0 +1,779 @@
+/*
+ * pmlinuxalsa.c -- system specific definitions
+ *
+ * written by:
+ * Roger Dannenberg (port to Alsa 0.9.x)
+ * Clemens Ladisch (provided code examples and invaluable consulting)
+ * Jason Cohen, Rico Colon, Matt Filippone (Alsa 0.5.x implementation)
+ */
+
+#include "stdlib.h"
+#include "portmidi.h"
+#include "pmutil.h"
+#include "pminternal.h"
+#include "pmlinuxalsa.h"
+#include "string.h"
+#include "porttime.h"
+#include "pmlinux.h"
+
+#include <alsa/asoundlib.h>
+
+/* I used many print statements to debug this code. I left them in the
+ * source, and you can turn them on by changing false to true below:
+ */
+#define VERBOSE_ON 0
+#define VERBOSE if (VERBOSE_ON)
+
+#define MIDI_SYSEX 0xf0
+#define MIDI_EOX 0xf7
+
+#if SND_LIB_MAJOR == 0 && SND_LIB_MINOR < 9
+#error needs ALSA 0.9.0 or later
+#endif
+
+/* to store client/port in the device descriptor */
+#define MAKE_DESCRIPTOR(client, port) ((void*)(((client) << 8) | (port)))
+#define GET_DESCRIPTOR_CLIENT(info) ((((int)(info)) >> 8) & 0xff)
+#define GET_DESCRIPTOR_PORT(info) (((int)(info)) & 0xff)
+
+#define BYTE unsigned char
+
+extern pm_fns_node pm_linuxalsa_in_dictionary;
+extern pm_fns_node pm_linuxalsa_out_dictionary;
+
+static snd_seq_t *seq = NULL; // all input comes here,
+ // output queue allocated on seq
+static int queue, queue_used; /* one for all ports, reference counted */
+
+typedef struct alsa_descriptor_struct {
+ int client;
+ int port;
+ int this_port;
+ int in_sysex;
+ snd_midi_event_t *parser;
+ int error; /* host error code */
+} alsa_descriptor_node, *alsa_descriptor_type;
+
+
+/* get_alsa_error_text -- copy error text to potentially short string */
+/**/
+static void get_alsa_error_text(char *msg, int len, int err)
+{
+ int errlen = strlen(snd_strerror(err));
+ if (errlen < len) {
+ strcpy(msg, snd_strerror(err));
+ } else if (len > 20) {
+ sprintf(msg, "Alsa error %d", err);
+ } else if (len > 4) {
+ strcpy(msg, "Alsa");
+ } else {
+ msg[0] = 0;
+ }
+}
+
+
+/* queue is shared by both input and output, reference counted */
+static PmError alsa_use_queue(void)
+{
+ if (queue_used == 0) {
+ snd_seq_queue_tempo_t *tempo;
+
+ queue = snd_seq_alloc_queue(seq);
+ if (queue < 0) {
+ pm_hosterror = queue;
+ return pmHostError;
+ }
+ snd_seq_queue_tempo_alloca(&tempo);
+ snd_seq_queue_tempo_set_tempo(tempo, 480000);
+ snd_seq_queue_tempo_set_ppq(tempo, 480);
+ pm_hosterror = snd_seq_set_queue_tempo(seq, queue, tempo);
+ if (pm_hosterror < 0)
+ return pmHostError;
+
+ snd_seq_start_queue(seq, queue, NULL);
+ snd_seq_drain_output(seq);
+ }
+ ++queue_used;
+ return pmNoError;
+}
+
+
+static void alsa_unuse_queue(void)
+{
+ if (--queue_used == 0) {
+ snd_seq_stop_queue(seq, queue, NULL);
+ snd_seq_drain_output(seq);
+ snd_seq_free_queue(seq, queue);
+ VERBOSE printf("queue freed\n");
+ }
+}
+
+
+/* midi_message_length -- how many bytes in a message? */
+static int midi_message_length(PmMessage message)
+{
+ message &= 0xff;
+ if (message < 0x80) {
+ return 0;
+ } else if (message < 0xf0) {
+ static const int length[] = {3, 3, 3, 3, 2, 2, 3};
+ return length[(message - 0x80) >> 4];
+ } else {
+ static const int length[] = {
+ -1, 2, 3, 2, 0, 0, 1, -1, 1, 0, 1, 1, 1, 0, 1, 1};
+ return length[message - 0xf0];
+ }
+}
+
+
+static PmError alsa_out_open(PmInternal *midi, void *driverInfo)
+{
+ void *client_port = descriptors[midi->device_id].descriptor;
+ alsa_descriptor_type desc = (alsa_descriptor_type)
+ pm_alloc(sizeof(alsa_descriptor_node));
+ snd_seq_port_info_t *info;
+ int err;
+
+ if (!desc) return pmInsufficientMemory;
+
+ snd_seq_port_info_alloca(&info);
+ snd_seq_port_info_set_port(info, midi->device_id);
+ snd_seq_port_info_set_capability(info, SND_SEQ_PORT_CAP_WRITE |
+ SND_SEQ_PORT_CAP_READ);
+ snd_seq_port_info_set_type(info, SND_SEQ_PORT_TYPE_MIDI_GENERIC |
+ SND_SEQ_PORT_TYPE_APPLICATION);
+ snd_seq_port_info_set_port_specified(info, 1);
+ err = snd_seq_create_port(seq, info);
+ if (err < 0) goto free_desc;
+
+ /* fill in fields of desc, which is passed to pm_write routines */
+ midi->descriptor = desc;
+ desc->client = GET_DESCRIPTOR_CLIENT(client_port);
+ desc->port = GET_DESCRIPTOR_PORT(client_port);
+ desc->this_port = midi->device_id;
+ desc->in_sysex = 0;
+
+ desc->error = 0;
+
+ err = snd_midi_event_new(PM_DEFAULT_SYSEX_BUFFER_SIZE, &desc->parser);
+ if (err < 0) goto free_this_port;
+
+ if (midi->latency > 0) { /* must delay output using a queue */
+ err = alsa_use_queue();
+ if (err < 0) goto free_parser;
+
+ err = snd_seq_connect_to(seq, desc->this_port, desc->client, desc->port);
+ if (err < 0) goto unuse_queue; /* clean up and return on error */
+ } else {
+ err = snd_seq_connect_to(seq, desc->this_port, desc->client, desc->port);
+ if (err < 0) goto free_parser; /* clean up and return on error */
+ }
+ return pmNoError;
+
+ unuse_queue:
+ alsa_unuse_queue();
+ free_parser:
+ snd_midi_event_free(desc->parser);
+ free_this_port:
+ snd_seq_delete_port(seq, desc->this_port);
+ free_desc:
+ pm_free(desc);
+ pm_hosterror = err;
+ if (err < 0) {
+ get_alsa_error_text(pm_hosterror_text, PM_HOST_ERROR_MSG_LEN, err);
+ }
+ return pmHostError;
+}
+
+
+static PmError alsa_write_byte(PmInternal *midi, unsigned char byte,
+ PmTimestamp timestamp)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ snd_seq_event_t ev;
+ int err;
+
+ snd_seq_ev_clear(&ev);
+ if (snd_midi_event_encode_byte(desc->parser, byte, &ev) == 1) {
+ snd_seq_ev_set_dest(&ev, desc->client, desc->port);
+ snd_seq_ev_set_source(&ev, desc->this_port);
+ if (midi->latency > 0) {
+ /* compute relative time of event = timestamp - now + latency */
+ PmTimestamp now = (midi->time_proc ?
+ midi->time_proc(midi->time_info) :
+ Pt_Time(NULL));
+ int when = timestamp;
+ /* if timestamp is zero, send immediately */
+ /* otherwise compute time delay and use delay if positive */
+ if (when == 0) when = now;
+ when = (when - now) + midi->latency;
+ if (when < 0) when = 0;
+ VERBOSE printf("timestamp %d now %d latency %d, ",
+ (int) timestamp, (int) now, midi->latency);
+ VERBOSE printf("scheduling event after %d\n", when);
+ /* message is sent in relative ticks, where 1 tick = 1 ms */
+ snd_seq_ev_schedule_tick(&ev, queue, 1, when);
+ /* NOTE: for cases where the user does not supply a time function,
+ we could optimize the code by not starting Pt_Time and using
+ the alsa tick time instead. I didn't do this because it would
+ entail changing the queue management to start the queue tick
+ count when PortMidi is initialized and keep it running until
+ PortMidi is terminated. (This should be simple, but it's not
+ how the code works now.) -RBD */
+ } else { /* send event out without queueing */
+ VERBOSE printf("direct\n");
+ /* ev.queue = SND_SEQ_QUEUE_DIRECT;
+ ev.dest.client = SND_SEQ_ADDRESS_SUBSCRIBERS; */
+ snd_seq_ev_set_direct(&ev);
+ }
+ VERBOSE printf("sending event\n");
+ err = snd_seq_event_output(seq, &ev);
+ if (err < 0) {
+ desc->error = err;
+ return pmHostError;
+ }
+ }
+ return pmNoError;
+}
+
+
+static PmError alsa_out_close(PmInternal *midi)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ if (!desc) return pmBadPtr;
+
+ if (pm_hosterror = snd_seq_disconnect_to(seq, desc->this_port,
+ desc->client, desc->port)) {
+ // if there's an error, try to delete the port anyway, but don't
+ // change the pm_hosterror value so we retain the first error
+ snd_seq_delete_port(seq, desc->this_port);
+ } else { // if there's no error, delete the port and retain any error
+ pm_hosterror = snd_seq_delete_port(seq, desc->this_port);
+ }
+ if (midi->latency > 0) alsa_unuse_queue();
+ snd_midi_event_free(desc->parser);
+ midi->descriptor = NULL; /* destroy the pointer to signify "closed" */
+ pm_free(desc);
+ if (pm_hosterror) {
+ get_alsa_error_text(pm_hosterror_text, PM_HOST_ERROR_MSG_LEN,
+ pm_hosterror);
+ return pmHostError;
+ }
+ return pmNoError;
+}
+
+
+static PmError alsa_in_open(PmInternal *midi, void *driverInfo)
+{
+ void *client_port = descriptors[midi->device_id].descriptor;
+ alsa_descriptor_type desc = (alsa_descriptor_type)
+ pm_alloc(sizeof(alsa_descriptor_node));
+ snd_seq_port_info_t *info;
+ snd_seq_port_subscribe_t *sub;
+ snd_seq_addr_t addr;
+ int err;
+
+ if (!desc) return pmInsufficientMemory;
+
+ err = alsa_use_queue();
+ if (err < 0) goto free_desc;
+
+ snd_seq_port_info_alloca(&info);
+ snd_seq_port_info_set_port(info, midi->device_id);
+ snd_seq_port_info_set_capability(info, SND_SEQ_PORT_CAP_WRITE |
+ SND_SEQ_PORT_CAP_READ);
+ snd_seq_port_info_set_type(info, SND_SEQ_PORT_TYPE_MIDI_GENERIC |
+ SND_SEQ_PORT_TYPE_APPLICATION);
+ snd_seq_port_info_set_port_specified(info, 1);
+ err = snd_seq_create_port(seq, info);
+ if (err < 0) goto free_queue;
+
+ /* fill in fields of desc, which is passed to pm_write routines */
+ midi->descriptor = desc;
+ desc->client = GET_DESCRIPTOR_CLIENT(client_port);
+ desc->port = GET_DESCRIPTOR_PORT(client_port);
+ desc->this_port = midi->device_id;
+ desc->in_sysex = 0;
+
+ desc->error = 0;
+
+ VERBOSE printf("snd_seq_connect_from: %d %d %d\n",
+ desc->this_port, desc->client, desc->port);
+ snd_seq_port_subscribe_alloca(&sub);
+ addr.client = snd_seq_client_id(seq);
+ addr.port = desc->this_port;
+ snd_seq_port_subscribe_set_dest(sub, &addr);
+ addr.client = desc->client;
+ addr.port = desc->port;
+ snd_seq_port_subscribe_set_sender(sub, &addr);
+ snd_seq_port_subscribe_set_time_update(sub, 1);
+ /* this doesn't seem to work: messages come in with real timestamps */
+ snd_seq_port_subscribe_set_time_real(sub, 0);
+ err = snd_seq_subscribe_port(seq, sub);
+ /* err =
+ snd_seq_connect_from(seq, desc->this_port, desc->client, desc->port); */
+ if (err < 0) goto free_this_port; /* clean up and return on error */
+ return pmNoError;
+
+ free_this_port:
+ snd_seq_delete_port(seq, desc->this_port);
+ free_queue:
+ alsa_unuse_queue();
+ free_desc:
+ pm_free(desc);
+ pm_hosterror = err;
+ if (err < 0) {
+ get_alsa_error_text(pm_hosterror_text, PM_HOST_ERROR_MSG_LEN, err);
+ }
+ return pmHostError;
+}
+
+static PmError alsa_in_close(PmInternal *midi)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ if (!desc) return pmBadPtr;
+ if (pm_hosterror = snd_seq_disconnect_from(seq, desc->this_port,
+ desc->client, desc->port)) {
+ snd_seq_delete_port(seq, desc->this_port); /* try to close port */
+ } else {
+ pm_hosterror = snd_seq_delete_port(seq, desc->this_port);
+ }
+ alsa_unuse_queue();
+ pm_free(desc);
+ if (pm_hosterror) {
+ get_alsa_error_text(pm_hosterror_text, PM_HOST_ERROR_MSG_LEN,
+ pm_hosterror);
+ return pmHostError;
+ }
+ return pmNoError;
+}
+
+
+static PmError alsa_abort(PmInternal *midi)
+{
+ /* NOTE: ALSA documentation is vague. This is supposed to
+ * remove any pending output messages. If you can test and
+ * confirm this code is correct, please update this comment. -RBD
+ */
+ /* Unfortunately, I can't even compile it -- my ALSA version
+ * does not implement snd_seq_remove_events_t, so this does
+ * not compile. I'll try again, but it looks like I'll need to
+ * upgrade my entire Linux OS -RBD
+ */
+ /*
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ snd_seq_remove_events_t info;
+ snd_seq_addr_t addr;
+ addr.client = desc->client;
+ addr.port = desc->port;
+ snd_seq_remove_events_set_dest(&info, &addr);
+ snd_seq_remove_events_set_condition(&info, SND_SEQ_REMOVE_DEST);
+ pm_hosterror = snd_seq_remove_events(seq, &info);
+ if (pm_hosterror) {
+ get_alsa_error_text(pm_hosterror_text, PM_HOST_ERROR_MSG_LEN,
+ pm_hosterror);
+ return pmHostError;
+ }
+ */
+ printf("WARNING: alsa_abort not implemented\n");
+ return pmNoError;
+}
+
+
+#ifdef GARBAGE
+This is old code here temporarily for reference
+static PmError alsa_write(PmInternal *midi, PmEvent *buffer, int32_t length)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ int i, bytes;
+ unsigned char byte;
+ PmMessage msg;
+
+ desc->error = 0;
+ for (; length > 0; length--, buffer++) {
+ VERBOSE printf("message 0x%x\n", buffer->message);
+ if (Pm_MessageStatus(buffer->message) == MIDI_SYSEX)
+ desc->in_sysex = TRUE;
+ if (desc->in_sysex) {
+ msg = buffer->message;
+ for (i = 0; i < 4; i++) {
+ byte = msg; /* extract next byte to send */
+ alsa_write_byte(midi, byte, buffer->timestamp);
+ if (byte == MIDI_EOX) {
+ desc->in_sysex = FALSE;
+ break;
+ }
+ if (desc->error < 0) break;
+ msg >>= 8; /* shift next byte into position */
+ }
+ } else {
+ bytes = midi_message_length(buffer->message);
+ msg = buffer->message;
+ for (i = 0; i < bytes; i++) {
+ byte = msg; /* extract next byte to send */
+ VERBOSE printf("sending 0x%x\n", byte);
+ alsa_write_byte(midi, byte, buffer->timestamp);
+ if (desc->error < 0) break;
+ msg >>= 8; /* shift next byte into position */
+ }
+ }
+ }
+ if (desc->error < 0) return pmHostError;
+
+ VERBOSE printf("snd_seq_drain_output: 0x%x\n", (unsigned int) seq);
+ desc->error = snd_seq_drain_output(seq);
+ if (desc->error < 0) return pmHostError;
+
+ desc->error = pmNoError;
+ return pmNoError;
+}
+#endif
+
+
+static PmError alsa_write_flush(PmInternal *midi, PmTimestamp timestamp)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ VERBOSE printf("snd_seq_drain_output: 0x%x\n", (unsigned int) seq);
+ desc->error = snd_seq_drain_output(seq);
+ if (desc->error < 0) return pmHostError;
+
+ desc->error = pmNoError;
+ return pmNoError;
+}
+
+
+static PmError alsa_write_short(PmInternal *midi, PmEvent *event)
+{
+ int bytes = midi_message_length(event->message);
+ PmMessage msg = event->message;
+ int i;
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ for (i = 0; i < bytes; i++) {
+ unsigned char byte = msg;
+ VERBOSE printf("sending 0x%x\n", byte);
+ alsa_write_byte(midi, byte, event->timestamp);
+ if (desc->error < 0) break;
+ msg >>= 8; /* shift next byte into position */
+ }
+ if (desc->error < 0) return pmHostError;
+ desc->error = pmNoError;
+ return pmNoError;
+}
+
+
+/* alsa_sysex -- implements begin_sysex and end_sysex */
+PmError alsa_sysex(PmInternal *midi, PmTimestamp timestamp) {
+ return pmNoError;
+}
+
+
+static PmTimestamp alsa_synchronize(PmInternal *midi)
+{
+ return 0; /* linux implementation does not use this synchronize function */
+ /* Apparently, Alsa data is relative to the time you send it, and there
+ is no reference. If this is true, this is a serious shortcoming of
+ Alsa. If not true, then PortMidi has a serious shortcoming -- it
+ should be scheduling relative to Alsa's time reference. */
+}
+
+
+static void handle_event(snd_seq_event_t *ev)
+{
+ int device_id = ev->dest.port;
+ PmInternal *midi = descriptors[device_id].internalDescriptor;
+ PmEvent pm_ev;
+ PmTimeProcPtr time_proc = midi->time_proc;
+ PmTimestamp timestamp;
+
+ /* time stamp should be in ticks, using our queue where 1 tick = 1ms */
+ assert((ev->flags & SND_SEQ_TIME_STAMP_MASK) == SND_SEQ_TIME_STAMP_TICK);
+
+ /* if no time_proc, just return "native" ticks (ms) */
+ if (time_proc == NULL) {
+ timestamp = ev->time.tick;
+ } else { /* translate time to time_proc basis */
+ snd_seq_queue_status_t *queue_status;
+ snd_seq_queue_status_alloca(&queue_status);
+ snd_seq_get_queue_status(seq, queue, queue_status);
+ /* return (now - alsa_now) + alsa_timestamp */
+ timestamp = (*time_proc)(midi->time_info) + ev->time.tick -
+ snd_seq_queue_status_get_tick_time(queue_status);
+ }
+ pm_ev.timestamp = timestamp;
+ switch (ev->type) {
+ case SND_SEQ_EVENT_NOTEON:
+ pm_ev.message = Pm_Message(0x90 | ev->data.note.channel,
+ ev->data.note.note & 0x7f,
+ ev->data.note.velocity & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_NOTEOFF:
+ pm_ev.message = Pm_Message(0x80 | ev->data.note.channel,
+ ev->data.note.note & 0x7f,
+ ev->data.note.velocity & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_KEYPRESS:
+ pm_ev.message = Pm_Message(0xa0 | ev->data.note.channel,
+ ev->data.note.note & 0x7f,
+ ev->data.note.velocity & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_CONTROLLER:
+ pm_ev.message = Pm_Message(0xb0 | ev->data.note.channel,
+ ev->data.control.param & 0x7f,
+ ev->data.control.value & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_PGMCHANGE:
+ pm_ev.message = Pm_Message(0xc0 | ev->data.note.channel,
+ ev->data.control.value & 0x7f, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_CHANPRESS:
+ pm_ev.message = Pm_Message(0xd0 | ev->data.note.channel,
+ ev->data.control.value & 0x7f, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_PITCHBEND:
+ pm_ev.message = Pm_Message(0xe0 | ev->data.note.channel,
+ (ev->data.control.value + 0x2000) & 0x7f,
+ ((ev->data.control.value + 0x2000) >> 7) & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_CONTROL14:
+ if (ev->data.control.param < 0x20) {
+ pm_ev.message = Pm_Message(0xb0 | ev->data.note.channel,
+ ev->data.control.param,
+ (ev->data.control.value >> 7) & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ pm_ev.message = Pm_Message(0xb0 | ev->data.note.channel,
+ ev->data.control.param + 0x20,
+ ev->data.control.value & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ } else {
+ pm_ev.message = Pm_Message(0xb0 | ev->data.note.channel,
+ ev->data.control.param & 0x7f,
+ ev->data.control.value & 0x7f);
+
+ pm_read_short(midi, &pm_ev);
+ }
+ break;
+ case SND_SEQ_EVENT_SONGPOS:
+ pm_ev.message = Pm_Message(0xf2,
+ ev->data.control.value & 0x7f,
+ (ev->data.control.value >> 7) & 0x7f);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_SONGSEL:
+ pm_ev.message = Pm_Message(0xf3,
+ ev->data.control.value & 0x7f, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_QFRAME:
+ pm_ev.message = Pm_Message(0xf1,
+ ev->data.control.value & 0x7f, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_START:
+ pm_ev.message = Pm_Message(0xfa, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_CONTINUE:
+ pm_ev.message = Pm_Message(0xfb, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_STOP:
+ pm_ev.message = Pm_Message(0xfc, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_CLOCK:
+ pm_ev.message = Pm_Message(0xf8, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_TUNE_REQUEST:
+ pm_ev.message = Pm_Message(0xf6, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_RESET:
+ pm_ev.message = Pm_Message(0xff, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_SENSING:
+ pm_ev.message = Pm_Message(0xfe, 0, 0);
+ pm_read_short(midi, &pm_ev);
+ break;
+ case SND_SEQ_EVENT_SYSEX: {
+ const BYTE *ptr = (const BYTE *) ev->data.ext.ptr;
+ /* assume there is one sysex byte to process */
+ pm_read_bytes(midi, ptr, ev->data.ext.len, timestamp);
+ break;
+ }
+ }
+}
+
+
+static PmError alsa_poll(PmInternal *midi)
+{
+ snd_seq_event_t *ev;
+ /* expensive check for input data, gets data from device: */
+ while (snd_seq_event_input_pending(seq, TRUE) > 0) {
+ /* cheap check on local input buffer */
+ while (snd_seq_event_input_pending(seq, FALSE) > 0) {
+ /* check for and ignore errors, e.g. input overflow */
+ /* note: if there's overflow, this should be reported
+ * all the way through to client. Since input from all
+ * devices is merged, we need to find all input devices
+ * and set all to the overflow state.
+ * NOTE: this assumes every input is ALSA based.
+ */
+ int rslt = snd_seq_event_input(seq, &ev);
+ if (rslt >= 0) {
+ handle_event(ev);
+ } else if (rslt == -ENOSPC) {
+ int i;
+ for (i = 0; i < pm_descriptor_index; i++) {
+ if (descriptors[i].pub.input) {
+ PmInternal *midi = (PmInternal *)
+ descriptors[i].internalDescriptor;
+ /* careful, device may not be open! */
+ if (midi) Pm_SetOverflow(midi->queue);
+ }
+ }
+ }
+ }
+ }
+ return pmNoError;
+}
+
+
+static unsigned int alsa_has_host_error(PmInternal *midi)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ return desc->error;
+}
+
+
+static void alsa_get_host_error(PmInternal *midi, char *msg, unsigned int len)
+{
+ alsa_descriptor_type desc = (alsa_descriptor_type) midi->descriptor;
+ int err = (pm_hosterror || desc->error);
+ get_alsa_error_text(msg, len, err);
+}
+
+
+pm_fns_node pm_linuxalsa_in_dictionary = {
+ none_write_short,
+ none_sysex,
+ none_sysex,
+ none_write_byte,
+ none_write_short,
+ none_write_flush,
+ alsa_synchronize,
+ alsa_in_open,
+ alsa_abort,
+ alsa_in_close,
+ alsa_poll,
+ alsa_has_host_error,
+ alsa_get_host_error
+};
+
+pm_fns_node pm_linuxalsa_out_dictionary = {
+ alsa_write_short,
+ alsa_sysex,
+ alsa_sysex,
+ alsa_write_byte,
+ alsa_write_short, /* short realtime message */
+ alsa_write_flush,
+ alsa_synchronize,
+ alsa_out_open,
+ alsa_abort,
+ alsa_out_close,
+ none_poll,
+ alsa_has_host_error,
+ alsa_get_host_error
+};
+
+
+/* pm_strdup -- copy a string to the heap. Use this rather than strdup so
+ * that we call pm_alloc, not malloc. This allows portmidi to avoid
+ * malloc which might cause priority inversion. Probably ALSA is going
+ * to call malloc anyway, so this extra work here may be pointless.
+ */
+char *pm_strdup(const char *s)
+{
+ int len = strlen(s);
+ char *dup = (char *) pm_alloc(len + 1);
+ strcpy(dup, s);
+ return dup;
+}
+
+
+PmError pm_linuxalsa_init( void )
+{
+ int err;
+ snd_seq_client_info_t *cinfo;
+ snd_seq_port_info_t *pinfo;
+ unsigned int caps;
+
+ /* Previously, the last parameter was SND_SEQ_NONBLOCK, but this
+ * would cause messages to be dropped if the ALSA buffer fills up.
+ * The correct behavior is for writes to block until there is
+ * room to send all the data. The client should normally allocate
+ * a large enough buffer to avoid blocking on output.
+ * Now that blocking is enabled, the seq_event_input() will block
+ * if there is no input data. This is not what we want, so must
+ * call seq_event_input_pending() to avoid blocking.
+ */
+ err = snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX, 0);
+ if (err < 0) return err;
+
+ snd_seq_client_info_alloca(&cinfo);
+ snd_seq_port_info_alloca(&pinfo);
+
+ snd_seq_client_info_set_client(cinfo, -1);
+ while (snd_seq_query_next_client(seq, cinfo) == 0) {
+ snd_seq_port_info_set_client(pinfo, snd_seq_client_info_get_client(cinfo));
+ snd_seq_port_info_set_port(pinfo, -1);
+ while (snd_seq_query_next_port(seq, pinfo) == 0) {
+ if (snd_seq_port_info_get_client(pinfo) == SND_SEQ_CLIENT_SYSTEM)
+ continue; /* ignore Timer and Announce ports on client 0 */
+ caps = snd_seq_port_info_get_capability(pinfo);
+ if (!(caps & (SND_SEQ_PORT_CAP_SUBS_READ | SND_SEQ_PORT_CAP_SUBS_WRITE)))
+ continue; /* ignore if you cannot read or write port */
+ if (caps & SND_SEQ_PORT_CAP_SUBS_WRITE) {
+ if (pm_default_output_device_id == -1)
+ pm_default_output_device_id = pm_descriptor_index;
+ pm_add_device("ALSA",
+ pm_strdup(snd_seq_port_info_get_name(pinfo)),
+ FALSE,
+ MAKE_DESCRIPTOR(snd_seq_port_info_get_client(pinfo),
+ snd_seq_port_info_get_port(pinfo)),
+ &pm_linuxalsa_out_dictionary);
+ }
+ if (caps & SND_SEQ_PORT_CAP_SUBS_READ) {
+ if (pm_default_input_device_id == -1)
+ pm_default_input_device_id = pm_descriptor_index;
+ pm_add_device("ALSA",
+ pm_strdup(snd_seq_port_info_get_name(pinfo)),
+ TRUE,
+ MAKE_DESCRIPTOR(snd_seq_port_info_get_client(pinfo),
+ snd_seq_port_info_get_port(pinfo)),
+ &pm_linuxalsa_in_dictionary);
+ }
+ }
+ }
+ return pmNoError;
+}
+
+
+void pm_linuxalsa_term(void)
+{
+ if (seq) {
+ snd_seq_close(seq);
+ pm_free(descriptors);
+ descriptors = NULL;
+ pm_descriptor_index = 0;
+ pm_descriptor_max = 0;
+ }
+}