--- /dev/null
+/*
+ * MIDI byte <-> sequencer event coder
+ *
+ * Copyright (C) 1998,99,2000 Takashi Iwai <tiwai@suse.de>,
+ * Jaroslav Kysela <perex@suse.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <malloc.h>
+#include <errno.h>
+#include "asoundlib.h"
+
+
+/* midi status */
+struct snd_midi_event {
+ int qlen; /* queue length */
+ int read; /* chars read */
+ int type; /* current event type */
+ unsigned char lastcmd;
+ int bufsize;
+ unsigned char *buf; /* input buffer */
+};
+
+
+/* queue type */
+/* from 0 to 7 are normal commands (note off, on, etc.) */
+#define ST_NOTEOFF 0
+#define ST_NOTEON 1
+#define ST_SPECIAL 8
+#define ST_SYSEX ST_SPECIAL
+/* from 8 to 15 are events for 0xf0-0xf7 */
+
+
+/* status event types */
+typedef void (*event_encode_t)(snd_midi_event_t *dev, snd_seq_event_t *ev);
+typedef void (*event_decode_t)(snd_seq_event_t *ev, unsigned char *buf);
+
+/*
+ * prototypes
+ */
+static void note_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void one_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void pitchbend_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void two_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void one_param_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void songpos_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
+static void note_decode(snd_seq_event_t *ev, unsigned char *buf);
+static void one_param_decode(snd_seq_event_t *ev, unsigned char *buf);
+static void pitchbend_decode(snd_seq_event_t *ev, unsigned char *buf);
+static void two_param_decode(snd_seq_event_t *ev, unsigned char *buf);
+static void songpos_decode(snd_seq_event_t *ev, unsigned char *buf);
+
+/*
+ * event list
+ */
+static struct status_event_list_t {
+ int event;
+ int qlen;
+ event_encode_t encode;
+ event_decode_t decode;
+} status_event[] = {
+ /* 0x80 - 0xf0 */
+ {SND_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode},
+ {SND_SEQ_EVENT_NOTEON, 2, note_event, note_decode},
+ {SND_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode},
+ {SND_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode},
+ {SND_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode},
+ {SND_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode},
+ {SND_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode},
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf0 */
+ /* 0xf0 - 0xff */
+ {SND_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */
+ {SND_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */
+ {SND_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */
+ {SND_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf4 */
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf5 */
+ {SND_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf7 */
+ {SND_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xf9 */
+ {SND_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */
+ {SND_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */
+ {SND_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */
+ {SND_SEQ_EVENT_NONE, 0, NULL, NULL}, /* 0xfd */
+ {SND_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */
+ {SND_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */
+};
+
+static int extra_decode_ctrl14(snd_midi_event_t *dev, unsigned char *buf, int len, snd_seq_event_t *ev);
+
+static struct extra_event_list_t {
+ int event;
+ int (*decode)(snd_midi_event_t *dev, unsigned char *buf, int len, snd_seq_event_t *ev);
+} extra_event[] = {
+ {SND_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},
+ /*{SND_SEQ_EVENT_NONREGPARAM, extra_decode_nrpn},*/
+ /*{SND_SEQ_EVENT_REGPARAM, extra_decode_rpn},*/
+};
+
+#define numberof(ary) (sizeof(ary)/sizeof(ary[0]))
+
+/*
+ * new/delete record
+ */
+
+int snd_midi_event_new(int bufsize, snd_midi_event_t **rdev)
+{
+ snd_midi_event_t *dev;
+
+ *rdev = NULL;
+ dev = (snd_midi_event_t *)malloc(sizeof(snd_midi_event_t));
+ if (dev == NULL)
+ return -ENOMEM;
+ if (bufsize > 0) {
+ dev->buf = malloc(bufsize);
+ if (dev->buf == NULL) {
+ free(dev);
+ return -ENOMEM;
+ }
+ }
+ dev->bufsize = bufsize;
+ *rdev = dev;
+ return 0;
+}
+
+void snd_midi_event_free(snd_midi_event_t *dev)
+{
+ if (dev != NULL) {
+ if (dev->buf)
+ free(dev->buf);
+ free(dev);
+ }
+}
+
+/*
+ * initialize record
+ */
+inline static void reset_encode(snd_midi_event_t *dev)
+{
+ dev->read = 0;
+ dev->qlen = 0;
+ dev->type = 0;
+}
+
+void snd_midi_event_reset_encode(snd_midi_event_t *dev)
+{
+ reset_encode(dev);
+}
+
+void snd_midi_event_reset_decode(snd_midi_event_t *dev)
+{
+ dev->lastcmd = 0xff;
+}
+
+void snd_midi_event_init(snd_midi_event_t *dev)
+{
+ snd_midi_event_reset_encode(dev);
+ snd_midi_event_reset_decode(dev);
+}
+
+/*
+ * resize buffer
+ */
+int snd_midi_event_resize_buffer(snd_midi_event_t *dev, int bufsize)
+{
+ unsigned char *new_buf, *old_buf;
+
+ if (bufsize == dev->bufsize)
+ return 0;
+ new_buf = malloc(bufsize);
+ if (new_buf == NULL)
+ return -ENOMEM;
+ old_buf = dev->buf;
+ dev->buf = new_buf;
+ dev->bufsize = bufsize;
+ reset_encode(dev);
+ if (old_buf)
+ free(old_buf);
+ return 0;
+}
+
+/*
+ * read bytes and encode to sequencer event if finished
+ * return the size of encoded bytes
+ */
+long snd_midi_event_encode(snd_midi_event_t *dev, unsigned char *buf, long count, snd_seq_event_t *ev)
+{
+ long result = 0;
+ int rc;
+
+ ev->type = SND_SEQ_EVENT_NONE;
+
+ while (count-- > 0) {
+ rc = snd_midi_event_encode_byte(dev, *buf++, ev);
+ result++;
+ if (rc < 0)
+ return rc;
+ else if (rc > 0)
+ return result;
+ }
+
+ return result;
+}
+
+/*
+ * read one byte and encode to sequencer event:
+ * return 1 if MIDI bytes are encoded to an event
+ * 0 data is not finished
+ * negative for error
+ */
+int snd_midi_event_encode_byte(snd_midi_event_t *dev, int c, snd_seq_event_t *ev)
+{
+ int rc = 0;
+
+ c &= 0xff;
+
+ if (c >= SND_MCMD_COMMON_CLOCK) {
+ /* real-time event */
+ ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
+ ev->flags &= ~SND_SEQ_EVENT_LENGTH_MASK;
+ ev->flags |= SND_SEQ_EVENT_LENGTH_FIXED;
+ return 1;
+ }
+
+ if (dev->qlen > 0) {
+ /* rest of command */
+ dev->buf[dev->read++] = c;
+ if (dev->type != ST_SYSEX)
+ dev->qlen--;
+ } else {
+ /* new command */
+ dev->read = 1;
+ if (c & 0x80) {
+ dev->buf[0] = c;
+ if ((c & 0xf0) == 0xf0) /* special events */
+ dev->type = (c & 0x0f) + ST_SPECIAL;
+ else
+ dev->type = (c >> 4) & 0x07;
+ dev->qlen = status_event[dev->type].qlen;
+ } else {
+ /* process this byte as argument */
+ dev->buf[dev->read++] = c;
+ dev->qlen = status_event[dev->type].qlen - 1;
+ }
+ }
+ if (dev->qlen == 0) {
+ ev->type = status_event[dev->type].event;
+ ev->flags &= ~SND_SEQ_EVENT_LENGTH_MASK;
+ ev->flags |= SND_SEQ_EVENT_LENGTH_FIXED;
+ if (status_event[dev->type].encode) /* set data values */
+ status_event[dev->type].encode(dev, ev);
+ rc = 1;
+ } else if (dev->type == ST_SYSEX) {
+ if (c == SND_MCMD_COMMON_SYSEX_END ||
+ dev->read >= dev->bufsize) {
+ ev->flags &= ~SND_SEQ_EVENT_LENGTH_MASK;
+ ev->flags |= SND_SEQ_EVENT_LENGTH_VARIABLE;
+ ev->data.ext.len = dev->read;
+ ev->data.ext.ptr = dev->buf;
+ if (c != SND_MCMD_COMMON_SYSEX_END)
+ dev->read = 0; /* continue to parse */
+ else
+ reset_encode(dev); /* all parsed */
+ rc = 1;
+ }
+ }
+
+ return rc;
+}
+
+/* encode note event */
+static void note_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.note.channel = dev->buf[0] & 0x0f;
+ ev->data.note.note = dev->buf[1];
+ ev->data.note.velocity = dev->buf[2];
+}
+
+/* encode one parameter controls */
+static void one_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.control.channel = dev->buf[0] & 0x0f;
+ ev->data.control.value = dev->buf[1];
+}
+
+/* encode pitch wheel change */
+static void pitchbend_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.control.channel = dev->buf[0] & 0x0f;
+ ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
+}
+
+/* encode midi control change */
+static void two_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.control.channel = dev->buf[0] & 0x0f;
+ ev->data.control.param = dev->buf[1];
+ ev->data.control.value = dev->buf[2];
+}
+
+/* encode one parameter value*/
+static void one_param_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.control.value = dev->buf[1];
+}
+
+/* encode song position */
+static void songpos_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
+{
+ ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
+}
+
+/*
+ * decode from a sequencer event to midi bytes
+ * return the size of decoded midi events
+ */
+long snd_midi_event_decode(snd_midi_event_t *dev, unsigned char *buf, long count, snd_seq_event_t *ev)
+{
+ int cmd;
+ long qlen;
+ unsigned int type;
+
+ if (ev->type == SND_SEQ_EVENT_NONE)
+ return -ENOENT;
+
+ for (type = 0; type < numberof(status_event); type++) {
+ if (ev->type == status_event[type].event)
+ goto __found;
+ }
+ for (type = 0; type < numberof(extra_event); type++) {
+ if (ev->type == extra_event[type].event)
+ return extra_event[type].decode(dev, buf, count, ev);
+ }
+ return -ENOENT;
+
+ __found:
+ if (type >= ST_SPECIAL)
+ cmd = 0xf0 + (type - ST_SPECIAL);
+ else
+ /* data.note.channel and data.control.channel is identical */
+ cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
+
+
+ if (cmd == SND_MCMD_COMMON_SYSEX) {
+ qlen = ev->data.ext.len;
+ if (count < qlen)
+ return -ENOMEM;
+ switch (ev->flags & SND_SEQ_EVENT_LENGTH_MASK) {
+ case SND_SEQ_EVENT_LENGTH_FIXED:
+ case SND_SEQ_EVENT_LENGTH_VARIPC:
+ return -EINVAL; /* invalid event */
+ }
+ memcpy(dev->buf, ev->data.ext.ptr, qlen);
+ return qlen;
+ } else {
+ unsigned char xbuf[4];
+
+ if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd) {
+ dev->lastcmd = cmd;
+ xbuf[0] = cmd;
+ if (status_event[type].decode)
+ status_event[type].decode(ev, xbuf + 1);
+ qlen = status_event[type].qlen + 1;
+ } else {
+ if (status_event[type].decode)
+ status_event[type].decode(ev, xbuf + 0);
+ qlen = status_event[type].qlen;
+ }
+ if (count < qlen)
+ return -ENOMEM;
+ memcpy(buf, xbuf, qlen);
+ return qlen;
+ }
+}
+
+
+/* decode note event */
+static void note_decode(snd_seq_event_t *ev, unsigned char *buf)
+{
+ buf[0] = ev->data.note.note & 0x7f;
+ buf[1] = ev->data.note.velocity & 0x7f;
+}
+
+/* decode one parameter controls */
+static void one_param_decode(snd_seq_event_t *ev, unsigned char *buf)
+{
+ buf[0] = ev->data.control.value & 0x7f;
+}
+
+/* decode pitch wheel change */
+static void pitchbend_decode(snd_seq_event_t *ev, unsigned char *buf)
+{
+ int value = ev->data.control.value + 8192;
+ buf[0] = value & 0x7f;
+ buf[1] = (value >> 7) & 0x7f;
+}
+
+/* decode midi control change */
+static void two_param_decode(snd_seq_event_t *ev, unsigned char *buf)
+{
+ buf[0] = ev->data.control.param & 0x7f;
+ buf[1] = ev->data.control.value & 0x7f;
+}
+
+/* decode song position */
+static void songpos_decode(snd_seq_event_t *ev, unsigned char *buf)
+{
+ buf[0] = ev->data.control.value & 0x7f;
+ buf[1] = (ev->data.control.value >> 7) & 0x7f;
+}
+
+/* decode 14bit control */
+static int extra_decode_ctrl14(snd_midi_event_t *dev, unsigned char *buf, int count, snd_seq_event_t *ev)
+{
+ if (ev->data.control.param < 32) {
+ if (count < 5)
+ return -ENOMEM;
+ buf[0] = SND_MCMD_CONTROL|(ev->data.control.channel & 0x0f);
+ buf[1] = ev->data.control.param;
+ buf[2] = (ev->data.control.value >> 7) & 0x7f;
+ buf[3] = ev->data.control.param + 32;
+ buf[4] = ev->data.control.value & 0x7f;
+ dev->lastcmd = buf[0];
+ return 5;
+ } else {
+ if (count < 3)
+ return -ENOMEM;
+ buf[0] = SND_MCMD_CONTROL|(ev->data.control.channel & 0x0f);
+ buf[1] = ev->data.control.param & 0x7f;
+ buf[4] = ev->data.control.value & 0x7f;
+ dev->lastcmd = buf[0];
+ return 3;
+ }
+}
git://git.alsa-project.org / alsa-lib.git / commitdiff