/**

 * \file seq/seq_midi_event.c

 * \brief MIDI byte <-> sequencer event coder

 * \author Takashi Iwai <tiwai@suse.de>

 * \author Jaroslav Kysela <perex@perex.cz>

 * \date 2000-2001

 */

/*

 *  MIDI byte <-> sequencer event coder

 *

 *  Copyright (C) 1998,99,2000 Takashi Iwai <tiwai@suse.de>,

 *			       Jaroslav Kysela <perex@perex.cz>

 *

 *

 *   This library is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU Lesser General Public License as

 *   published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

 *

 *   You should have received a copy of the GNU Lesser General Public

 *   License along with this library; if not, write to the Free Software

 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <malloc.h>

#include "local.h"

#ifndef DOC_HIDDEN

/* midi status */

struct snd_midi_event {

	ssize_t qlen;	/* queue length */

	size_t read;	/* chars read */

	int type;	/* current event type */

	unsigned char lastcmd;

	unsigned char nostat;

	size_t bufsize;

	unsigned char *buf;	/* input buffer */

};

/* event type, index into status_event[] */

/* from 0 to 6 are normal commands (note off, on, etc.) for 0x8?-0xe? */

#define ST_INVALID	7

#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)(const snd_seq_event_t *ev, unsigned char *buf);

#endif /* DOC_HIDDEN */

/*

 * 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(const snd_seq_event_t *ev, unsigned char *buf);

static void one_param_decode(const snd_seq_event_t *ev, unsigned char *buf);

static void pitchbend_decode(const snd_seq_event_t *ev, unsigned char *buf);

static void two_param_decode(const snd_seq_event_t *ev, unsigned char *buf);

static void songpos_decode(const snd_seq_event_t *ev, unsigned char *buf);

/*

 * event list

 */

#ifndef DOC_HIDDEN

static const struct status_event_list_t {

	int event;

	int qlen;

	event_encode_t encode;

	event_decode_t decode;

} status_event[] = {

	/* 0x80 - 0xef */

	{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},

	/* invalid */

	{SND_SEQ_EVENT_NONE,		-1, NULL, NULL},

	/* 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,		-1, NULL, NULL}, /* 0xf4 */

	{SND_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf5 */

	{SND_SEQ_EVENT_TUNE_REQUEST,	 0, NULL, NULL}, /* 0xf6 */

	{SND_SEQ_EVENT_NONE,		-1, NULL, NULL}, /* 0xf7 */

	{SND_SEQ_EVENT_CLOCK,		 0, NULL, NULL}, /* 0xf8 */

	{SND_SEQ_EVENT_NONE,		-1, 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, 		-1, 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, const snd_seq_event_t *ev);

static int extra_decode_xrpn(snd_midi_event_t *dev, unsigned char *buf, int count, const snd_seq_event_t *ev);

static const struct extra_event_list_t {

	int event;

	int (*decode)(snd_midi_event_t *dev, unsigned char *buf, int len, const snd_seq_event_t *ev);

} extra_event[] = {

	{SND_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},

	{SND_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn},

	{SND_SEQ_EVENT_REGPARAM, extra_decode_xrpn},

};

#define numberof(ary)	(sizeof(ary)/sizeof(ary[0]))

#endif /* DOC_HIDDEN */

/**

 * \brief Creates a MIDI event parser.

 * \param[in] bufsize Size of the buffer used for encoding; this should be

 *                    large enough to hold the largest MIDI message to be

 *                    encoded.

 * \param[out] rdev The new MIDI event parser.

 * \return Zero on success, otherwise a negative error code.

 *

 * This function creates and initializes a MIDI parser object that can be used

 * to convert a MIDI byte stream to sequencer events (encoding) and/or to

 * convert sequencer events to a MIDI byte stream (decoding).

 *

 * \par Errors:

 * 

 * 
-ENOMEM
Out of memory.

 *

 * \par Conforming to:

 * LSB 3.2

 */

int snd_midi_event_new(size_t bufsize, snd_midi_event_t **rdev)

{

	snd_midi_event_t *dev;

	*rdev = NULL;

	dev = (snd_midi_event_t *)calloc(1, 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;

	dev->lastcmd = 0xff;

	dev->type = ST_INVALID;

	*rdev = dev;

	return 0;

}

/**

 * \brief Frees a MIDI event parser.

 * \param dev MIDI event parser.

 *

 * Frees a MIDI event parser.

 *

 * \par Conforming to:

 * LSB 3.2

 */

void snd_midi_event_free(snd_midi_event_t *dev)

{

	if (dev != NULL) {

		free(dev->buf);

		free(dev);

	}

}

/**

 * \brief Enables/disables MIDI command merging.

 * \param dev MIDI event parser.

 * \param on 0 to enable MIDI command merging,

 *           1 to always write the command byte.

 *

 * This function enables or disables MIDI command merging (running status).

 *

 * When MIDI command merging is not disabled, #snd_midi_event_decode is allowed

 * to omit any status byte that is identical to the previous status byte.

 */

void snd_midi_event_no_status(snd_midi_event_t *dev, int on)

{

	dev->nostat = on ? 1 : 0;

}

/*

 * initialize record

 */

inline static void reset_encode(snd_midi_event_t *dev)

{

	dev->read = 0;

	dev->qlen = 0;

	dev->type = ST_INVALID;

}

/**

 * \brief Resets MIDI encode parser.

 * \param dev MIDI event parser.

 *

 * This function resets the MIDI encoder of the parser \a dev.

 * Any partially encoded MIDI message is dropped,

 * and running status state is cleared.

 *

 * \par Conforming to:

 * LSB 3.2

 */

void snd_midi_event_reset_encode(snd_midi_event_t *dev)

{

	reset_encode(dev);

}

/**

 * \brief Resets MIDI decode parser.

 * \param dev MIDI event parser.

 *

 * This function resets the MIDI decoder of the parser \a dev.

 * The next decoded message does not use running status from before the call to

 * \a snd_midi_event_reset_decode.

 *

 * \par Conforming to:

 * LSB 3.2

 */

void snd_midi_event_reset_decode(snd_midi_event_t *dev)

{

	dev->lastcmd = 0xff;

}

/**

 * \brief Resets MIDI encode/decode parsers.

 * \param dev MIDI event parser.

 *

 * This function resets both encoder and decoder of the MIDI event parser.

 * \sa snd_midi_event_reset_encode, snd_midi_event_reset_decode

 *

 * \par Conforming to:

 * LSB 3.2

 */

void snd_midi_event_init(snd_midi_event_t *dev)

{

	snd_midi_event_reset_encode(dev);

	snd_midi_event_reset_decode(dev);

}

/**

 * \brief Resizes the MIDI message encoding buffer.

 * \param dev MIDI event parser.

 * \param bufsize The new buffer size.

 * \return Zero on success, otherwise a negative error code.

 *

 * This function resizes the buffer that is used to hold partially encoded MIDI

 * messages.

 *

 * If there is a partially encoded message in the buffer, it is dropped.

 *

 * \par Errors:

 * 

 * 
-ENOMEM
Out of memory.

 *

 * \sa snd_midi_event_encode, snd_midi_event_reset_encode

 */

int snd_midi_event_resize_buffer(snd_midi_event_t *dev, size_t 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);

	free(old_buf);

	return 0;

}

/**

 * \brief Encodes bytes to sequencer event.

 * \param[in] dev MIDI event parser.

 * \param[in] buf Buffer containing bytes of a raw MIDI stream.

 * \param[in] count Number of bytes in \a buf.

 * \param[out] ev Sequencer event.

 * \return The number of bytes consumed, or a negative error code.

 *

 * This function tries to use up to \a count bytes from the beginning of the

 * buffer to encode a sequencer event.  If a complete MIDI message has been

 * encoded, the sequencer event is written to \a ev; otherwise, \a ev->type is

 * set to #SND_SEQ_EVENT_NONE, and further bytes are required to complete

 * a message.

 *

 * The buffer in \a dev is used to hold any bytes of a not-yet-complete MIDI

 * message.  If a System Exclusive message is larger than the buffer, the

 * message is split into multiple parts, and a sequencer event is returned at

 * the end of each part.

 *

 * Any bytes that are not part of a valid MIDI message are silently ignored,

 * i.e., they are consumed without signaling an error.

 *

 * When this function returns a system exclusive sequencer event (\a ev->type

 * is #SND_SEQ_EVENT_SYSEX), the data pointer (\a ev->data.ext.ptr) points into

 * the MIDI event parser's buffer.  Therefore, the sequencer event can only be

 * used as long as that buffer remains valid, i.e., until the next call to

 * #snd_midi_event_encode, #snd_midi_event_encode_byte,

 * #snd_midi_event_resize_buffer, #snd_midi_event_init,

 * #snd_midi_event_reset_encode, or #snd_midi_event_free for that MIDI event

 * parser.

 *

 * This function can generate any sequencer event that corresponds to a MIDI

 * message, i.e.:

 * - #SND_SEQ_EVENT_NOTEOFF

 * - #SND_SEQ_EVENT_NOTEON

 * - #SND_SEQ_EVENT_KEYPRESS

 * - #SND_SEQ_EVENT_CONTROLLER

 * - #SND_SEQ_EVENT_PGMCHANGE

 * - #SND_SEQ_EVENT_CHANPRESS

 * - #SND_SEQ_EVENT_PITCHBEND

 * - #SND_SEQ_EVENT_SYSEX

 * - #SND_SEQ_EVENT_QFRAME

 * - #SND_SEQ_EVENT_SONGPOS

 * - #SND_SEQ_EVENT_SONGSEL

 * - #SND_SEQ_EVENT_TUNE_REQUEST

 * - #SND_SEQ_EVENT_CLOCK

 * - #SND_SEQ_EVENT_START

 * - #SND_SEQ_EVENT_CONTINUE

 * - #SND_SEQ_EVENT_STOP

 * - #SND_SEQ_EVENT_SENSING

 * - #SND_SEQ_EVENT_RESET

 * .

 * Some implementations may also be able to generate the following events

 * for a sequence of controller change messages:

 * - #SND_SEQ_EVENT_CONTROL14

 * - #SND_SEQ_EVENT_NONREGPARAM

 * - #SND_SEQ_EVENT_REGPARAM

 *

 * \par Conforming to:

 * LSB 3.2

 *

 * \sa snd_midi_event_new, snd_midi_event_reset_encode, snd_midi_event_encode_byte

 */

long snd_midi_event_encode(snd_midi_event_t *dev, const 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;

}

/**

 * \brief Encodes byte to sequencer event.

 * \param[in] dev MIDI event parser.

 * \param[in] c A byte of a raw MIDI stream.

 * \param[out] ev Sequencer event.

 * \return 1 if a sequenver event has been completed, 0 if more bytes are

 *         required to complete an event, or a negative error code.

 *

 * This function tries to use the byte \a c to encode a sequencer event.  If

 * a complete MIDI message has been encoded, the sequencer event is written to

 * \a ev; otherwise, further bytes are required to complete a message.

 *

 * See also the description of #snd_midi_event_encode.

 *

 * \par Conforming to:

 * LSB 3.2

 *

 * \sa snd_midi_event_new, snd_midi_event_reset_encode, snd_midi_event_encode

 */

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 >= MIDI_CMD_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 ev->type != SND_SEQ_EVENT_NONE;

	}

	if ((c & 0x80) &&

	    (c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {

		/* new command */

		dev->buf[0] = c;

		if ((c & 0xf0) == 0xf0) /* system message */

			dev->type = (c & 0x0f) + ST_SPECIAL;

		else

			dev->type = (c >> 4) & 0x07;

		dev->read = 1;

		dev->qlen = status_event[dev->type].qlen;

	} else {

		if (dev->qlen > 0) {

			/* rest of command */

			dev->buf[dev->read++] = c;

			if (dev->type != ST_SYSEX)

				dev->qlen--;

		} else {

			/* running status */

			dev->buf[1] = c;

			dev->qlen = status_event[dev->type].qlen - 1;

			dev->read = 2;

		}

	}

	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);

		if (dev->type >= ST_SPECIAL)

			dev->type = ST_INVALID;

		rc = 1;

	} else 	if (dev->type == ST_SYSEX) {

		if (c == MIDI_CMD_COMMON_SYSEX_END ||

		    dev->read >= dev->bufsize) {

			ev->flags &= ~SND_SEQ_EVENT_LENGTH_MASK;

			ev->flags |= SND_SEQ_EVENT_LENGTH_VARIABLE;

			ev->type = SND_SEQ_EVENT_SYSEX;

			ev->data.ext.len = dev->read;

			ev->data.ext.ptr = dev->buf;

			if (c != MIDI_CMD_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];

}

/**

 * \brief Decodes sequencer event to MIDI byte stream.

 * \param[in] dev MIDI event parser.

 * \param[out] buf Buffer for the resulting MIDI byte stream.

 * \param[in] count Number of bytes in \a buf.

 * \param[in] ev The sequencer event to decode.

 * \return The number of bytes written to \a buf, or a negative error code.

 *

 * This function tries to decode the sequencer event into one or more MIDI

 * messages, and writes the raw MIDI byte(s) into \a buf.

 *

 * The generated MIDI messages may use running status, unless disabled with

 * #snd_midi_event_no_status.

 *

 * The required buffer size for a sequencer event it as most 12 bytes, except

 * for System Exclusive events (\a ev->type == #SND_SEQ_EVENT_SYSEX) which can

 * have any length (as specified by \a ev->data.ext.len).

 *

 * The following sequencer events correspond to MIDI messages:

 * - #SND_SEQ_EVENT_NOTEOFF

 * - #SND_SEQ_EVENT_NOTEON

 * - #SND_SEQ_EVENT_KEYPRESS

 * - #SND_SEQ_EVENT_CONTROLLER

 * - #SND_SEQ_EVENT_PGMCHANGE

 * - #SND_SEQ_EVENT_CHANPRESS

 * - #SND_SEQ_EVENT_PITCHBEND

 * - #SND_SEQ_EVENT_SYSEX

 * - #SND_SEQ_EVENT_QFRAME

 * - #SND_SEQ_EVENT_SONGPOS

 * - #SND_SEQ_EVENT_SONGSEL

 * - #SND_SEQ_EVENT_TUNE_REQUEST

 * - #SND_SEQ_EVENT_CLOCK

 * - #SND_SEQ_EVENT_START

 * - #SND_SEQ_EVENT_CONTINUE

 * - #SND_SEQ_EVENT_STOP

 * - #SND_SEQ_EVENT_SENSING

 * - #SND_SEQ_EVENT_RESET

 * - #SND_SEQ_EVENT_CONTROL14

 * - #SND_SEQ_EVENT_NONREGPARAM

 * - #SND_SEQ_EVENT_REGPARAM

 *

 * \par Errors:

 * 

 * 
-EINVAL
\a ev is not a valid sequencer event.

 * 
-ENOENT
The sequencer event does not correspond to one or more MIDI messages.

 * 
-ENOMEM
The MIDI message(s) would not fit into \a count bytes.

 *

 * \par Conforming to:

 * LSB 3.2

 *

 * \sa snd_midi_event_reset_decode, snd_midi_event_no_status

 */

long snd_midi_event_decode(snd_midi_event_t *dev, unsigned char *buf, long count, const 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 == MIDI_CMD_COMMON_SYSEX) {

		snd_midi_event_reset_decode(dev);

		qlen = ev->data.ext.len;

		if (count < qlen)

			return -ENOMEM;

		switch (ev->flags & SND_SEQ_EVENT_LENGTH_MASK) {

		case SND_SEQ_EVENT_LENGTH_FIXED:

			return -EINVAL;	/* invalid event */

		}

		memcpy(buf, ev->data.ext.ptr, qlen);

		return qlen;

	} else {

		unsigned char xbuf[4];

		if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {

			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 (qlen <= 0)

			return 0;

		if (count < qlen)

			return -ENOMEM;

		memcpy(buf, xbuf, qlen);

		return qlen;

	}

}

/* decode note event */

static void note_decode(const 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(const snd_seq_event_t *ev, unsigned char *buf)

{

	buf[0] = ev->data.control.value & 0x7f;

}

/* decode pitch wheel change */

static void pitchbend_decode(const 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(const 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(const 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, const snd_seq_event_t *ev)

{

	unsigned char cmd;

	int idx = 0;

	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);

	if (ev->data.control.param < 32) {

		if (count < 4)

			return -ENOMEM;

		if (dev->nostat && count < 6)

			return -ENOMEM;

		if (cmd != dev->lastcmd || dev->nostat) {

			if (count < 5)

				return -ENOMEM;

			buf[idx++] = dev->lastcmd = cmd;

		}

		buf[idx++] = ev->data.control.param;

		buf[idx++] = (ev->data.control.value >> 7) & 0x7f;

		if (dev->nostat)

			buf[idx++] = cmd;

		buf[idx++] = ev->data.control.param + 32;

		buf[idx++] = ev->data.control.value & 0x7f;

	} else {

		if (count < 2)

			return -ENOMEM;

		if (cmd != dev->lastcmd || dev->nostat) {

			if (count < 3)

				return -ENOMEM;

			buf[idx++] = dev->lastcmd = cmd;

		}

		buf[idx++] = ev->data.control.param & 0x7f;

		buf[idx++] = ev->data.control.value & 0x7f;

	}

	return idx;

}

/* decode reg/nonreg param */

static int extra_decode_xrpn(snd_midi_event_t *dev, unsigned char *buf, int count, const snd_seq_event_t *ev)

{

	unsigned char cmd;

	const char *cbytes;

	static const char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,

				       MIDI_CTL_NONREG_PARM_NUM_LSB,

				       MIDI_CTL_MSB_DATA_ENTRY,

				       MIDI_CTL_LSB_DATA_ENTRY };

	static const char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,

				       MIDI_CTL_REGIST_PARM_NUM_LSB,

				       MIDI_CTL_MSB_DATA_ENTRY,

				       MIDI_CTL_LSB_DATA_ENTRY };

	unsigned char bytes[4];

	int idx = 0, i;

	if (count < 8)

		return -ENOMEM;

	if (dev->nostat && count < 12)

		return -ENOMEM;

	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);

	bytes[0] = (ev->data.control.param & 0x3f80) >> 7;

	bytes[1] = ev->data.control.param & 0x007f;

	bytes[2] = (ev->data.control.value & 0x3f80) >> 7;

	bytes[3] = ev->data.control.value & 0x007f;

	if (cmd != dev->lastcmd && !dev->nostat) {

		if (count < 9)

			return -ENOMEM;

		buf[idx++] = dev->lastcmd = cmd;

	}

	cbytes = ev->type == SND_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;

	for (i = 0; i < 4; i++) {

		if (dev->nostat)

			buf[idx++] = dev->lastcmd = cmd;

		buf[idx++] = cbytes[i];

		buf[idx++] = bytes[i];

	}

	return idx;

}