/**
* \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:
* <dl>
* <dt>-ENOMEM<dd>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:
* <dl>
* <dt>-ENOMEM<dd>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:
* <dl>
* <dt>-EINVAL<dd>\a ev is not a valid sequencer event.
* <dt>-ENOENT<dd>The sequencer event does not correspond to one or more MIDI messages.
* <dt>-ENOMEM<dd>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;
}